Skip to main content

Full text of "Water,land and related resources Main report, sediment yield and land treatment"

See other formats


Historic, Archive Document 

Do not assume content reflects current 
scientific knowledge, policies, or practices. 







t 





















( Reserve 

Water, land, and related resources 



NORTH COASTAL AREA of CALIFORNIA 
and PORTIONS of SOUTHERN OREGON 



APPENDIX NO. 2 

SEDIMENT YIELD and 
LAND TREATMENT 


KLAMATH, TRINITY, AND SMITH 
RIVER BASINS; RUSSIAN RIVER, 
MENDOCINO COASTAL, 

AND CLEAR LAKE BASINS 



JUNE 1972 


Prepared by the 

UNITED STATES DEPARTMENT OF AGRICULTURE 
RIVER BASIN PLANNING STAFF 
SOIL CONSERVATION SERVICE FOREST SERVICE 
^ ECONOMIC RESEARCH SERVICE 

In cooperation with the 

CALIFORNIA DEPARTMENT OF WATER RESOURCES 


USDA-SCS-PORTLAND ORCGON 1972 














BooWtf* 

CI*M) 

NATIONAL 



LIBRARY 




WATER, LAND, AND RELATED RESOURCES 


North Coastal Area of California 
and Portions of Southern Oregon 

APPENDIX NO. 2 

Sediment Yield and Land Treatment 


Klamath, Trinity, and Smith River Basins; 

Russian River, Mendocino Coastal, and Clear Lake Basins 


Prepared by the 


t! S. DEPT. OF AGRICULTURE 
NATIONAL AGRIC' :! I LIBRARY 


U.S. Department of Agriculture 

River Basin Planning Staff APR - 31973 

Berkeley, California 


Soil Conservation Service 


CATALOGING - PREP, 


Darwyn H. Briggs, Head, River Basin Planning Staff 

William H. Payne, Watershed Staff Assistant 

Mark W. Sussman, Agricultural Economist 

Dwight K. Ellison, Soil Scientist 

Charles E. Stearns, State Geologist 

Romeo A. Rivera, Civil Engineer 

Gerald D. Osborn, Geologist 

W. Britton Pyland, Civil Engineering Technician 
Forest Service 

Lyle M. Klubben, Branch Chief, River Basin Programs 

Darwin B. Crezee, Soils Hydrologist 

James D. Cook, Forester 

Ronald W. Hanson, Forester 

James M. Kress, Hydrologist 

Glenn A. Roloff, Forester 

Economic Research Service 

Robert B. McKusick, Agricultural Economist 
John R. Wilkins, Agricultural Economist 

under Coordination of the 

US DA Field Advisory Committee 

Thomas P. Helseth, Soil Conservation Service, Chairman 

Carl N. Wilson, Forest Service 

Raymond S. Lanier, Economic Research Service 

in cooperation with the 

California Department of Water Resources 

June 1972 


1 



I 









371056 

ACKNOWLEDGEMENTS 


During the course of the sediment studies, the following organizations 
provided valuable assistance or information: 


FEDERAL AGENCIES STATE AGENCIES 

U.S. Department of Defense California Department of 

Conservat ion 

Corps of Engineers 

Division of Forestry 

U.S. Department of Interior 

Department of Water Resources 

Bureau of Reclamation 

Department of Fish and Game 

Geological Survey 

OTHERS 

U.S. Department of Agriculture 

Pacific Southwest Forest 
and Range Experiment 
Station (Forest Service ) 

Soil Conservation Service 

Areas I & II Area and Work 
Unit Staffs 

Economic Research Service 
COUNTY AGENCIES 

Mendocino County Engineer's Office 

Mendocino County Farm and Home 
Advisor's Office (Agricultural 
Extension Service) 

Humboldt County Farm and Home 

Advisor's Office (Agricultural 
Extension Service) 


University of California 

School of Forestry and 
Conservation 

Hopland Field Station 

Numerous private industries 
and citizens 


11 










APPENDIX NO. 2 


SEDIMENT YIELD AND LAND TREATMENT 
TABLE OF CONTENTS 


Page 

ACKNOWLEDGEMENTS. ii 

SUMMARY. ix 

GLOSSARY.... xiii 

INTRODUCTION . 1 

Need for the Study. 1 

Authority for the Study and Participating USDA Agencies . . 2 

Objectives of the Study. 2 

Description of the Study Area. 3 

Inter-Agency Coordination . 3 

Nature and Intensity of the Investigations. 4 

LAND RESOURCES AND USE. 5 

Available Data. 5 

Topography. 7 

Southern Basins. 7 

Northern Basins. 7 

Geology .. 8 

Southern Basins. 8 

Northern Basins. 10 

Soils. 12 

Southern Basins. 12 

Northern Basins. 13 

Vegetal Cover Types . l6 

Land Use. l8 

Timber Production. l8 

Cropland. 19 

Grazing. 19 

Recreation ..... . 20 

Wilderness. 20 

Fish and Wildlife. 21 

Mining.■ 22 

Other Land Uses. 22 

Laud Ownership and Administration. 23 

PROBLEMS. 25 

Sediment and Debris Deposition. 25 

Deposition Areas. 25 

Agricultural. 25 

Urban. 26 

Roads. 26 

Channel Deposition ... . 26 

Potential Future Problems . 28 

Destruction of Fish and Wildlife Habitat. 29 

iii 











































T A B L E OF CONTENTS 


Page 

Periodic Effect on Water Quality . 29 

Reservoir Sedimentation. 30 

Soil Erosion. 30 

Streambank Erosion . 30 

Landslides. 32 

Sheet and Gully Erosion. 32 

Logging. 32 

Grazing. 33 

Deer. 35 

Burning .. 35 

Recreation. 36 

Croplands. 36 

Roads. 36 

Limitation of Potential Land Use. 37 

Southern Basins. 37 

Northern Basins. 38 

Endangered Developments . 38 

Increased Costs for Land Operations . 38 

Increased Runoff Rates. 38 

Destruction of Fish and Wildlife Habitat. 38 

Destruction of Recreation Potential and Scenic Beauty ... 39 

Adverse Impact on Local Economy . 39 

SEDIMENT YIELD STUDIES AND SURVEY PROCEDURES. 40 

Sheet and Gully Erosion. 44 

Survey Procedures. 44 

Data Analys is. 46 

Present Sediment Yield . 47 

Southern Basins . 47 

Northern Basins . 49 

Future Sediment Yield. 52 

Landslide Erosion . 54 

Available Data. 54 

Survey Procedures. 54 

Data Analysis. .. 56 

Findings .. 56 

Southern Basins . 56 

Northern Basins . 58 

Cause of Landslides. 59 

Future Sediment Yield. 60 

Streambank Erosion. 60 

Available Data. 60 

Survey Procedures. 60 

Data Analysis. 62 

Present Sediment Yield . 63 

Southern Basins . 63 

Northern Basins . 67 

Influence of Man's Activity. 71 

Future Sediment Yield. 72 


iv 


















































TABLE OF CONTENTS 


Page 

LAND TREAT ME 1 ! NT FROGMMS. 73 

Remedial and Production Improvement Programs „ . 73 

Privately Owned Grassland . 73 

Natural Grass land--Southern Basins.74 

Measures...74- 

Slight Erosion Class . 74 

Moderate Erosion Class . 74 

Severe Erosion Class . 74 

Cost.75 

Natural Grass land--Northern Basins.75 

Measures...75 

Range Sites in Poor Condition.75 

Range Sites in Fair Condition.75 

Cost.78 

Converted Timberland . 78 

Measures. ......... . 78 

Area to be Reforested.78 

Area to Remain in Grass.80 

Severely Eroded Area .......... 80 

Cost. 80 

Effects of the Program.80 

Sediment Yield.80 

Production.80 

Publicly Owned Grassland.84 

Measures.84 

Cost.85 

Effects of the Program.85 

Sediment Yield.85 

Production.85 

Brushland.85 

Measures . ..... 86 

Cost.86 

Effects of the Program.86 

Roads ..87 

Measures and Costs.87 

Effects of the Program.89 

Management Guidelines.89 

Sheet and Gully Erosion ..89 

Logging Guidelines . 89 

Grazing Guidelines . 93 

Deer Guidelines.94 

Wildfire Guidelines.95 

Type Conversion Guidelines . 95 

Recreation Guidelines.96 

Cropland Guidelines.97 

Road Guidelines.97 

Mining Guidelines. . . 106 

Streambanks.108 

Landslides.109 

Other Studies on Landslide Problems.109 


v 























































TABLE OF CONTENTS 


Page 

Effects of the Management Guidelines. Ill 

Summary of the Effects of the Land Treatment Program. . . . Ill 

Sediment Yield . Ill 

Production. 113 

Water Quantity and Quality. 113 

Fish and Wildlife. 113 

Scenic Beauty and Recreation . Il4 

Monetary and Social Benefits . Il4 

Implementation. Il4 

Problems. Il4 

Needs. 115 

OPPORTUNITIES FOR DEVELOPMENT THROUGH US DA PROGRAMS. 117 

Watershed Protection and Flood Prevention Projects 

(Public Law 566). 117 

Resource Conservation District Programs . 118 

Conservation Operations (Public Law 46) . . 120 

Rural Environmental Assistance Program. 120 

Farm and Home Administration loan Programs. 121 

Agricultural Extension Service. 122 

Resource Conservation and Development Projects. 122 

Cooperative State and Federal Forestry Programs . 123 

National Forest Development and Multiple Use Programs . . . 125 

OTHER ACTIONS NEEDED. 127 

Changes Needed in USDA Programs. 127 

New Programs or Legislation Needed . 128 

ADDENDUM. 130 

Special Sediment Studies. 130 

Reservoir Sediment Surveys . 130 

Procedures. 130 

Findings. 132 

Suspended Sediment Data . 132 

Available Data. 132 

Procedures. 133 

Soils Data. 135 

Soil Erosion Classes. 152 

MAPS Follows Page 

North Coastal River Basins . xiv 

Generalized Geologic Map--Southern Basins. 8 

Generalized Geologic Map--Northern Basins. 10 

General Soils (2). l4 

Vegetal Cover Types (2). l6 

Land Ownership and Administration (2). 24 

Annual Sediment Yield (2). 43 


vi 











































TABLE OF CONTENTS 


MAPS Follows Page 

Suspended Sediment Gaging Stations and Reservoir 

Sedimentation Surveys--Southern Basins ...... . 133 

Suspended Sediment Gaging Stations--Northern Basins . 133 

General Land Capability (2) . ..151 

Hydrologic Soil Groups (2).152 

TABLES Page 

Area of Major Geologic Units--Southern Basins . 9 

Area of Major Geologic Units--Northern Basins . 11 

Approximate Area of Soil Associations--Southern Basins. l4 

Approximate Area of Soil Associations--Northern Basins. 15 

Summary of Changes in Streambed Elevation . 27 

Present Annual Sediment Yields by Source. 42 

Future Annual Sediment Yields by Source Without Program . 43 

Present Sediment Yields and Rates from Sheet and 

Gully Erosion in the Southern Basins. 48 

Present Sediment Yields and Rates from Sheet and 

Gully Erosion in the Northern Basins. 50 

Present Sediment Yields and Rates from Landslides . 57 

Present Annual Sediment Yield from Streambanks in the 

Southern Basins. 64 

Length of Stream Channels in the Southern Basins. 65 

Annual Sediment Rate Per Mile of Stream in the 

Southern Basins. ...... . 66 

Present Annual Sediment Yield from Streambanks 

in the.Northern Basins . ..... 68 

Length of Stream Channels in the Northern Basins. 69 

Annual Sediment Rate Per Mile of Stream in the Northern Basins. . 70 

Estimated Costs of the Private Natural Grassland Program 

in the Southern Basins. 76 

Estimated Costs of the Private Natural Grassland Program 

in the Northern Basins. 79 

Estimated Costs of the Private Converted Timberland 

Program in the Southern Basins . 8l 

Effects of the Privately Owned Grassland Programs 

in the Southern Basins .. 82 

Grass Forage Production on Privately Owned Grassland. 83 

Estimated Measures and Costs for National Forest Roads 

in the Northern Basins. 88 

Guidelines for Land Use and Minimum Conservation Treatment 

of Land Suited for Cultivation (Southern Basins).99“101 

Guidelines for Land Use and Minimum Conservation Treatment 

of Land Suited for Cultivation (Northern Basins).102-103 

Reservoir Sedimentation Summary . 131 

Mean Annual Sediment Discharge for the Period 1940-65 . 134 

Soil Characteristics, Qualities, and Interpretive Groupings-- 

Southern Basins.136-l4l 

vii 


































n li LK OK 0 0 N T E N T 0 

TABLES Page 

Soil Characteristics, Qualities, and Interpretive Groupings-- 

Northern Basins. 142-147 

Distribution of Land Capability Classes . 150 

PHOTOGRAPHS 

View of Klamath River.xii 

Aerial View of Dry Creek Watershed. 4 

Landslide in Road Fill. 31 

Sediment Deposition in Farm Pond. . .. 31 

Overgrazed Range Site. 34 

Landslide on State Highway 299. 39 

Sediment Deposition in Orchard and Reservoir (2). 40 

Severe Sheet and Gully Erosion (2). 45 

Road Erosion (2). 51 

Landslides (2).' . 55 

Streambank Erosion (2). 6l 

Range Site Conditions (3). 77 

Poorly Logged Land vs. Contoured Cut Blocks (2). 91 

Severely Eroded Converted Timberland. 93 

Effect of Improperly Installed Road Culvert (2) . 104 

Road Encroaching Upon Stream.105 

Gold Dredge Tailings.106 

Severe Erosion Caused by Hydraulic Mining . 107 

Landslide Caused by Poor Drainage Conditions.110 

Treatment Measures on Landslide . Ill 

Fish Pond Built with SCS Assistance.119 

Woodland Soil Site Correlation.119 

Reservoir Sedimentation Survey.132 


viii 




























SUMMARY 


The California Department of Water Resources requested a reconnaissance- 
level study of sources and causes of the high sediment yields in the 
Ilorth Coastal Area and an assessment of the ability of existing USDA 
programs to solve the problems identified by the study. This study!/ 
is made in conjunction with water development studies of other federal 
and state agencies. 

The study area is separated geographically by the Eel and Mad River 
Basins, and there are significant physiographic and climatic differences 
between the northern and southern portions; therefore, the two have been 
treated separately in much of this presentation. The Northern Basins 
include the Smith and Trinity River Basins and the California portion 
of the Klamath Basin, comprising some 10,795 square miles; the Southern 
Basins encompass the Mendocino Coastal Streams (several relatively 
short rivers that flow directly into the Pacific Ocean), the Russian 
River, and Clear Lake Basins, comprising some 4,04l square miles. With 
the exception of the Clear Lake Basin, where runoff flows into the 
Sacramento River, the rivers outlet directly into the Pacific Ocean. 

Steep, mountainous terrain interspersed with narrow valleys typifies 
most of the area. The soils are generally characterized by their 
inherent high erodibility, and the parent rock by its weak, fractured 
nature and its susceptibility to landsliding. The major topographical 
exception is the relatively flat Modoc Plateau in the Upper Klamath 
Basin, where the soils are generally stable. Rainfall is heavy in the 
coastal regions and diminishes progressively from west to east, ranging 
from over 100 to about 10 inches per year. 

This appendix presents the general physical characteristics and 
resources of the basins, such as topography, soil associations, geology, 
vegetal cover types, and land use and ownership. It describes the 
procedures used to investigate erosion, determine sediment yields, 
and formulate a land treatment program. Sediment rates are given for 
the various sources and causes, and possibilities for implementing the 
land treatment program are discussed. 


4-'This publication is the second of( two appendices to the report, 

Water, Land, and Related Resources--North Coastal Area of California 

and Portions of Southern Oregon. The first covers the Eel and Mad 
River Basins; this one deals with the remaining river basins in the 
North Coastal Area and will be followed by the main report. 










Sediment yields are summarized as follows: 


Basins 


Land Area 
(Square Miles) 


Estimated 
Sediment Yield 
(Acre-Feet/Year) 


Estimated Rate Of 
Sediment Yield 
( Acre-Feet/Sq.Mile/Year) 


Present 


Northern 10,795 5,9^0 0.6 


Southern 

4,o4i 

4,950 

1.2 

Total 

14,836 

10,890 

0.7 


Future Without 

Recommended Program 


Northern 

10,795 

6,520 

0.6 

Southern 

4,o4l 

6,090 

1.5 

Total 

14,836 

12,610 

0.9 


Future With 

Recommended Program 


Northern 

10,795 

4,850 

0.5 

Southern 

4,o4i 

4,870 

1.2 

Total 

14,836 

9,720 

0.7 


Three sources of sediment -- streambank, landslide, and sheet and gully 
erosion -- were found to yield 46, 26 , and 28 percent, respectively, 
of the total sediment. In the Northern Basins the percentages were 48, 
31, and 21 and in the Southern Basins 45, 19, and 36 , respectively. 
Natural causes are responsible for about 80 percent of sediment from 
streambanks, 75 percent of that from landslides, but only about 20 
percent of that from sheet and gully erosion. 

Two types of land treatment programs are recommended -- those designed 
mainly to reduce sediment yield and those designed primarily to increase 
production. Guidelines to improve land management and prevent future 
problems are also presented. 

The following is a tabulation of the programs, their costs, and their 
effects in sediment reduction and/or production improvement. 


x 



















Annual 

Sediment 

Annual 


Installation 

Reduction 

Production 

Increases^/ 

Program 

Cost ($1,000) 

(Acre-Feet) 

Private Lands 




Grassland 




Natural 

10,509 

190 

424,000 AUM 

Converted Timberland 

3,150 

110 

9,000 AUM§/ 
8 Mil.Cu.Ft 

Brushland Conversion 

To Timberland 

9,232 

20 

14 Mil.Cu.Ft 

Public Lands 




Grassland Conversion 

To Timberland 

1,792 

- 

5 Mil.Cu.Ft 

Brushland Conversion 

To Timberland 

3,077 

10 

5 Mil.Cu.Ft 

Roads 

62,349 

48o 

- 

Total 

90,109 

8io2/ 

433,000 AUM 




32 Mil.Cu.Ft, 


1 / 


Grass increases are shown as animal-unit-months of grazing, and timber 
increases are shown in millions of cubic feet. 


2 / 

3/ 


Part of the converted timberland will be reforested, and the rest will 
be managed as grassland. 


Adherence to the management guidelines would reduce sediment yield an 
additional 2,080 acre-feet. 


Programs recommended include only those that were found to be econ¬ 
omically feasible over large areas. Many remedial measures, such as 
streambank and landslide stabilization, were determined too costly for 
normal onsite benefits. However, many such measures may be economically 
feasible in localized areas where high values are involved. 

Under present policy and funding, USDA programs could accomplish only 
about 16 percent of the land treatment program recommended in this 
appendix. If USDA programs were to be accelerated, about 24 percent 
could be realized. Such acceleration would require increased funds 
as well as intensified informational efforts to interest more land- 
owners . 


xi 















To accomplish the entire land treatment program, it will be necessary 
to modify USDA programs so that specific needs of the basins can be 
fully met. Some proposed modifications are presented in this appendix. 
For complete success, it is essential that the full capabilities of all 
USDA, state, and local agencies be utilized and that the local people, 
particularly the owners of grazing land, become deeply involved. 

Alternative solutions are presented in the form of ideas for new 
programs and legislation that could successfully accomplish the program. 




' T < r 


View of the Klamath River*. 


USFS PHOTO 




GLOSSARY 


The Following terms appear periodically in this appendix and are defined 
here to avoid repetition: 

ANIMAL UNIT -- A measure of livestock numbers by which kinds, classes, 
sizes, and ages are converted to an approximate common standard in 
relation to feed and forage resources and is based on the equivalent 
of one mature cow (1,000 pounds, live weight). 

ANIMAL UNIT MONTH (AUM) -- A measure of forage or feed requirement to 
maintain one animal unit for 30 days. See ANIMAL UNIT. 

BEDLQAD -- The sediment that moves by sliding, rolling, or bouncing 
on or very near the streambed; sediment moved mainly by tractive or 
gravitational forces or both, but at a velocity less than that of the 
surrounding flow. 

DEBRIS SLIDE -- Involves natural soil, unconsolidated sedimentary 
material, and weathered rock and is usually limited to material that 
overlies firm bedrock. 

INFILTRATION -- The process whereby water passes through an interface, 
such as from air to soil or between two soil horizons. 

PERCOLATION -- The movement of water within a porous medium such as 
soil. 

PRESENT CONDITION -- The average condition for the 24-year study period 
(1941-19^5). The 24-year period was selected because it was the longest 
interval between flights of the available sets of aerial photographs 
that could be compared. 

SEDIMENT DISCHARGE -- The rate at which dry weight of sediment passes 
a section of a stream or is the quantity of sediment, as measured by 
dry weight-or volume, that is discharged in a given time. 

SEDIMENT YIELD -- The amount of sediment carried past a given point. 

SHEET EROSION -- The removal of a fairly uniform layer of soil from 
the land surface by overland flow; includes rill networks up to six 
inches deep. 

SUSPENDED SEDIMENT -- The sediment that at a given time is maintained 
in suspension by the upward components of turbulent currents or that 
exists in suspension as a colloid. 

TRAP EFFICIENCY -- The ratio of the amount of sediment retained in a 
reservoir in respect to the total sediment yield brought into the 
reservoir. 


xiii 


















WATERSHED -- All lands enclosed by a continuous hydrologic drainage 
divide above a specified point on a stream. 

WATERSHED MANAGEMENT 1 -- The inspection, analysis, protection, develop¬ 
ment, operation, or maintenance of the land, vegetation, fishery, and 
water resources of a drainage basin for the conservation of all its 
resources for the benefit of man. Watershed management for water 
production is concerned with the quality, quantity, and demand schedule 
of the water that is produced. 

WATER TRANSMISSION -- The movement of water in the soil within and 
across soil horizons. 


xiv 





SMITH RIVER BASIN 


KLAMATH RIVER BASIN 


MAD RIVER BASIN' 


EEL RIVER BASIN 





































/ 


/ 





INTRODUCTION 


NEED FOR THE STUDY 


An important mission of the California Resources Agency and its Depart¬ 
ment of Water Resources is the implementation of the State Water Project, 
a part of the California Water Plan currently financed to the extent of 
.$1.75 billion as a result of the approval of the California Water 
Resources Bond Act by the voters in i 960 . This Act included provisions 
for financing additional facilities to augment water supplies in the 
Sacramento-San Joaquin Delta. In 1957, the Department's Bulletin No. 3, 
"The California Water Plan," identified the North Coast as the principal 
remaining source of substantial surface water supplies to meet future 
needs of the State. In 1964, the Department's Bulletin No. 136, "North 
Coastal Area Investigations," concluded that the most favorable North 
Coastal project for augmenting State Water Project supplies in the Delta 
would involve a multiple-purpose reservoir on the Middle Fork Eel River. 
Bulletin 136 also recommended continuing reconnaissance studies of plans 
for later North Coastal projects. In cooperation with the Department 
and in coordination with the U.S. Department of Defense, Corps of 
Engineers, and the U.S. Department of the Interior, Bureau of Recla¬ 
mation, the U.S. Department of Agriculture undertook an extensive study 
of the North Coastal Area within one of its particular areas of exper¬ 
tise -- namely the sources and causes of the high sediment yields and 
the ability of USD4 programs to solve the problems identified. 

Sediment yield is a major problem in the North Coastal Areas, as illus¬ 
trated by the fact that the Eel River carried over 100 million tons 
( 50,000 acre-feet) of sediment during the 1964 record flood. 

Economic development of these basins has taken place slowly and has not 
reached a high level when compared to other parts of California; 
unemployment has been high in parts of the basins, and all nine counties 
in this area of California are designated as eligible for a full finan¬ 
cial assistance program under the Economic Development Administration 
of the U.S. Department of Commerce. Inaccessibility and remoteness 
from markets have been the primary deterrents to economic growth. 

With construction of better highways, now underway, these impediments 
are lessening. 

Both past and present land management practices have damaged the water¬ 
shed to the detriment of the general economy. First, heavy use of 
grazing lands continues; second, indiscriminate skid logging and repeat¬ 
ed accidental and prescribed burning dates from the early 1900 's to 
the present; third, road construction and subsequent erosion and sedi¬ 
ment yield continues; and fourth, sporadic dredge and devastating hydrau¬ 
lic pilacer mining for gold occurred from the mid to late l 800 's. 

This publication is the second of two appendices to the report Water, 
Land, and Related Resources -- North Coastal Area of California and 

Portions cf Southern Oregon. Appendix No. 1 covers the Eel and Mad 


1 








River Basins in California and presents the findings of the sediment 
yield and land treatment studies. This appendix presents the same type 
of information on the remaining basins in the North Coastal Area. The 
portion of the Klamath River in Oregon is being studied by the USDA 
River Basin Staff in that state, and their report will be appended to 
the Main Report for the North Coastal Area. 

The overall investigation includes all streams that flow into the 
Pacific Ocean from the Russian River in the south to the Smith River 
near the Oregon border. The portions of the Klamath and Smith River 
Basins in Oregon are included in the study area. The total area en¬ 
compasses about 25,000 square miles, of which about 19,500 square miles 
are in California and 5,500 square miles are in Oregon. 


AUTHORITY FOR THE STUDY AND PARTICIPATING USDA AGENCIES 


On March 11, 1964, the California Department of Water Resources request¬ 
ed the U.S. Department of Agriculture to cooperate with other state and 
federal agencies in a study of the Eel River Basin. In the course of 
inter-agency deliberations, the Department of Water Resources extended 
its request to encompass the entire area of the North Coastal Basins. 

The Department of Agriculture agreed to participate in such a study 
under the authority of Section 6 of the Public Law 566 , as amended. 

The Department of Agriculture agencies that participated in the study 
are the Economic Research Service, the Forest Service, and the Soil 
Conservation Service. 


OBJECTIVES OF THE STUDY 


The survey has five major objectives: 

1. To estimate the sediment yield by sources and causes under 
present conditions. 

2. To estimate the future sediment yield under the expected use and 
management. 

3. To formulate a land treatment program that would reduce the 
sediment yield and to estimate the costs of remedial measures. 

4. To evaluate the physical effects of the recommended program. 

5. To evaluate the potential development that could be obtained 
through U.S. Department of Agriculture programs. 


2 




DESCRIPTION OF THE STUDY AREA 


Results of studies made in the Russian River, Mendocino Coastal, and 
Clear Lake Basins in the southern portion of the North Coastal Area 
and in the Klamath, Trinity, and Smith River Basins to the north are 
reported in this appendix. Several small intervening coastal streams 
between the Klamath and Smith Rivers are included. This study area 
encompasses 14,904 square miles, of which l4,8l6 square miles are in 
California and 88 square miles of the Smith River drainage are in 
Oregon. Parts of Del Norte, Siskiyou, Modoc, Humboldt, Trinity, 
Mendocino, Sonoma, and Lake Counties in California and of Curry County 
in Oregon lie in the study area. A study of the 5,640 square miles in 
the Klamath River drainage in Oregon will be prepared by the USDA River 
Basin Staff in Oregon and will be presented in a separate report. 


INTER-AGENCY COORDINATION 


Coordination of the joint planning efforts in the North Coastal Area is 
provided by the California State-Federal Inter-Agency Group, which 
consists of the California Department of Water Resources, the Corps of 
Engineers, the Bureau of Reclamation, and the Soil Conservation Service. 
Other agencies are represented through their membership in the technical 
subgroups of the Inter-Agency Group. The objectives of the group are 
to facilitate coordination and cooperation among the various state and 
federal agencies and to eliminate duplication. 

Primary study responsibilities were assigned to the four agencies accord¬ 
ing to their major interests. The Department of Water Resources was 
assigned the responsibility for determining the state water requirements 
and providing the overall coordination for the joint planning efforts, 
the Corps of Engineers for flood control in the main streams and the 
major tributaries, the Bureau of Reclamation for irrigation water devel¬ 
opment at major projects and the development of hydroelectric power for 
inclusion into federal power transmissions, and the Soil Conservation 
Service for watershed management studies and the investigation of flood 
control and irrigation projects in connection with U.S. Department of 
Agriculture programs. 

The Inter-Agency Group will consider all agency study results in plan¬ 
ning development of water and related land resources in the North 
Coastal area. The main objective of such planning is to improve living 
conditions of the people by enhancing the physical environment and 
improving the economic opportunities. Consideration for the complete 
development of water and related land resources will be given to flood 
control, local water supplies, water quality control, hydroelectric 
power, recreation development, sediment and erosion reduction, improved 
watershed management practices, enhanced fishing and hunting programs, 
and possible export of excess water to water deficient areas of 
California. 


3 








NATURE AND INTENSITY OF THE INVESTIGATIONS 


Overall North Coastal Area investigations are being made at a recon¬ 
naissance level, with added emphasis placed on sediment yield problems. 
The intensity of the sediment yield studies was greater than that 
normally associated with a Type IV river basin survey. Watershed 
investigations were made to determine the opportunities for solving 
soil and water problems in the North Coastal Area through Public Law 
566 projects. The full potential for development of these watersheds 
was the main consideration of the investigations, which were made only 
in sufficient detail to assure that a project is feasible. 



Aerial view of Dry Creek Watershed } Russion river Basin . scs PH0T0 


4 



LAND RESOURCES AND USE 


Information regarding geology, soils, and vegetation is basic to 
studies of watershed management and serves as a guide in designing 
programs suited to the needs and limitations of the resource. After 
the inter-relationship of these factors is understood, interpretations 
regarding land use and management can be made. These include land 
capability classification for cropland, range, forest, and woodland 
production and the determination of suitability of sites for road 
location, recreation development, and the construction of buildings 
and other cultural features. 


AVAILABLE DATA 


Aerial photographs of the entire North Coastal Survey Area were taken 
in 1965 for this study and were used in combination with available older 
photographs. The oldest, taken in 194l, cover most of Mendocino County; 
1942, 1944, 1947, 1948, or 1952 photographs cover the remainder of the 
basins. 

The Santa Rosa, Ukiah, Redding, Weed, and Alturas sheets of the "Geologic 
Maps of California" published by the California Division of Mines and 
Geology!/ were used to develop a generalized geologic map. 

In compiling soils information, available data and maps were used 
extensively. The Soil-Vegetation Maps, prepared by the Pacific South¬ 
west Forest and Range Experiment Station with funding by the California 
Division of Forestry!./, cover the upland area outside the National 


California Resources Agency, Department of Conservation, Division of 
Mines and Geology, G eologic Map of California ; Ukiah Sheet. 

(San Francisco, 1960 "). 

. . . Alturas Sheet. ( 1958 ). 

. . . Redding Sheet. ( 1962 ). 

. . . Santa Rosa Sheet. ( 1963 ). 

. . . Weed Sheet. (1964) 


Cooperative Soil-Vegetation Survey Project: California Department of 
Natural Resources, Division of Forestry, in cooperation with the 
University of California and the USDA Forest Service California Forest 
and Range Experiment Station. Upland Soils fMap] of Lake County . 
(Sacramento; State Printing Division, Documents Section, 1955); 

Upland Soils [Map] of Mendocino County , (1951); Soil Vegetation Survey 
Maps . (San Francisco, USDA Forest Service, latest available editions). 


5 













Forests in Lake, Sonoma, Trinity, Mendocino, and Humboldt Counties and 
portions of' the Mendocino National Forest in Lake County. The survey 
team prepared generalized soil association maps using both published 
and unpublished data .%] through 5/ 

The most recent editions of U.S. Geologic Survey 15-minute topographic 
quadrangles were used to determine slope gradients when needed to supple¬ 
ment the Soil-Vegetation Maps. 

The Vegetal Cover Types Maps for the basins were prepared from Timber 
Stand Maps of the Soil-Vegetation Survey when they were available. For 
areas not covered by Soil-Vegetation Survey Maps, National Forest Timber 
Stand Maps were used.—/ Information from the maps was supplemented with 
vegetal cover interpretations made from 1965 aerial photographs. 


—^Robert A. Gardner and others, Wildland Soils and Associated Vegetation 
of Mendocino County, California^ (Sacramento; Resources Agency of 
California, Cooperative Soil-Vegetation Survey Project, 1964). 113 pp. 


2 / 

— James McLaughlin and Frank Harradine, Soils of Western Humboldt 
County, California . (Department of Soils and Plant Nutrition, Uni¬ 
versity of California, Davis, in cooperation with the County of 
Humboldt, November 1965 ). 85 pp. 


USDA Soil Conservation Service, Report and General Soil Map ; (for 
the following counties in California) Del Norte (12/67) 37 pp; 
Humboldt (4/67) 51 PP; Lake (4/67) 45 pp; Mendocino ( 2 / 67 ) 56 pp; 
Modoc (4/67) 49 pp; Siskiyou ( 3 / 67 ) 50 pp; Sonoma ( 1 / 67 ) 64 pp; 
Trinity ( 6 / 67 ) 30 pp. (Berkeley, California) Unpublished report. 




—'K.E. Lanspa and others, Siskiyou Study Area Soil Survey Report; Six 
Rivers-Klamath National Forests. (Unpublished Report) (San Francisco: 


5/ 


USDA Forest Service, California Region; October 1968 ). 52 pp. plus 
maps . 

( 

USDA Forest Service, California Region, Soil-Vegetation and Timber 
Stands Maps, Orleans Ranger District, Six Rivers National Forest . 

1964.(Unpublished maps and legend) 


6 / 

USDA Forest Service, Six Rivers National Forest, Timber Stand 
Maps . (San Francisco, 1967 ). 


6 














TOPOGRAPHY 


SOUTHERN BASINS 

The principal topographical features of Southern Basins -- the Russian, 
Mendocino Coastal, and Clear Lake Basins -- are the rugged northwest- 
southeast trending ridges and valleys. These reflect the geologic 
structural features of the basin, such as faults, folds, and contacts 
between formations, all of which have the same general alignment. The 
San Andreas Fault cuts through the western part of the basins and extends 
beneath the Pacific Ocean near Point Arena. This fault zone is charac¬ 
terized by a valley along most of its length. The Gualala and Garcia 
Rivers turn and follow the fault in their lower reaches. 

As a consequence of the topography, the general trend of the main 
streams in the basin in northwest-southeast, and those streams crossing 
the structural grain of the basin, usually do so at right angles, result¬ 
ing in a rectilinear pattern known as trellis drainage. 

Other important topographic features of these basins are the alluvial 
valleys, coastline, and a large lake. Most of the irrigable land occurs 
in the broad alluvial valleys scattered throughout the basin; the most 
prominent ones are Anderson, Potter, Redwood, and Ukiah Valleys, the 
flatlands around Clear Lake, and the alluvial plains around Santa Rosa 
and along the Russian River. The rugged coastline is noted for its 
spectacular and relatively unspoiled scenery. Clear Lake, located on 
the eastern side of the basins, is one of the largest natural fresh¬ 
water lakes in the State with a surface area of about 68 square miles. 
Lake Mendocino, a man-made lake in the Russian River Basin, is the only 
sizeable impoundment. 

NORTHERN BASINS 

The topography of Northern Basins -- the Klamath, Trinity, and Smith 
Basins -- is typified by rugged mountains and deep, narrow canyons in 
the western portion. The eastern portion consists of gently rolling to 
relatively flat plateau country dotted with many prominent volcanic 
cones. Mfc. Shasta, with an elevation of l4,l62 feet, one of the 
highest peaks in the United States, is the highest peak in the study 
area. 

The drainage pattern of most of the Trinity, Smith, and western Klamath 
Basins is dendritic --an irregular, branching pattern not controlled by 
underlying geologic structures. Some exceptions occur where streams 
flow parallel to the structural trend of the underlying rocks; examples 
are the South Fork Trinity River, and the lower reaches of the Klamath 
and Smith Rivers. 

In the eastern Klamath Basin, an area underlain by volcanic rocks, much 
of the drainage is disjointed and irregular. The volcanic topography 
is relatively smooth over a large area, but individual cones or small 
areas may have steep relief. Consequently, much of the precipitation 


7 





that falls on the area collects in small interior basins, where it 
evaporates or sinks into porous volcanic rock. 

Most of the irrigable land is in broad alluvial valleys, such as Hayfork 
and Hyampom Valleys in the Trinity Basin, and Scott, Shasta, Butte, and 
Tule Lake Valleys in the upper part of the Klamath Basin. The flood 
plain near the mouth of the Smith River also supports some irrigated 
crops. 

Spectacular scenery abounds in the basins. The area contains the 
Salmon-Trinity Alps Primitive Area, the Marble Mountain Wilderness, and 
part of the Yolla Bolly-Middle Eel Wilderness, totaling about 500,000 
acres. These are particularly impressive for their remoteness and scenic 
beauty. Small mountain lakes formed by glacial action are abundant in 
some of the high mountain regions. Clair Engle Lake, on the Trinity 
River, is the largest manmade lake in the basins; others include Lewis¬ 
ton Reservoir on the Trinity River, Dwinnell Reservoir on the Shasta 
River, and Copco and Iron Gate Reservoirs on the Klamath River. 


GEOLOGY 


SOUTHERN BASINS 

The basins contain rocks typically found in the Northern California 
Coast Ranges. The rocks range in age from Late Jurassic to Recent 
and are predominantly marine sediments. About 79 percent of the area 
is underlain by Franciscan rocks or rocks generally associated with the 
Franciscan. These rocks include the undivided Cretaceous marine sedi¬ 
mentary rocks or coastal belt rocks of the Franciscan formation (K), 
"typical" Franciscan rocks (KJf), Franciscan volcanic and metavolcanics 
(KJfv), and ultrabasic rocks, such as serpentinite (ub). The Great 
Valley sequence comprises about 3 percent of the rocks in the basins 
and is comprised of Upper (Ku) and Lower (Kl) Cretaceous marine sedi¬ 
mentary rocks. Tertiary marine (Tm) sediments comprise about 2 percent 
of the rocks; Pliocene and Pliestocene volcanic (QPv) and sedimentary 
(Qmc) rocks comprise 10 percent; and the remaining 6 percent of the 
basin is underlain by alluvium (Qal). The extent of these geologic 
assemblages in the various basins is shown on the Generalized Geologic 
Map and in the table "Area of Major Geologic Units" on the following 
pages. 

The Franciscan formation is a heterogeneous mass of sedimentary, 
volcanic, and metamorphic rocks highly fractured and deformed by fold¬ 
ing, faulting, and metamorphism. The formation has been intruded by 
basic and ultra-basic rocks that are predominantly serpentinized. The 
volcanic rocks, which are interbedded with marine sediments, are mostly 
submarine lava flows that are now largely altered to greenstone. By 
far the most prevalent rock type in the Franciscan formation is grey- 
wacke, a sandstone, which is commonly associated with minor amounts of 
shale. Chert is also common. The Great Valley sequence, although 
about the same age as the Franciscan formation, has less volcanic rock 



LEGEND 



GENERALIZED GEOLOGIC MAP 

SOUTHERN RIVER BASINS 

HUMBOLDT, LAKE, MENDOCINO. AND SONOMA COUNTIES, 
CALIFORNIA 

NOVEMBER 1971 

5 Q 5 10 15 MILES 

SCALE I 760,320 


MENDOCINO 
COASTAL 


•CLEAR LAKE 
SASIN 


i-marine sedimentary deposits 
Cache Formation-clays, silts, 
stream terrace deposits 
Glen Ellen Formation-clays. • 
marine terrace deposits 


Clear Lake Volcai 
flows and tuffs 
Sonoma Volcanics 
and rhyolite flo 


Tertiary marine sedimentary rocks 

Mattole River Basin: Wildcat Group: mudstone, siltstone. 

sandstone 

Southern Mendocino Basin: sandstone, siltstone. clay of Merced 

Formation; shale and sandstone of 
Point Arena Beds; other shales, 
sandstones and conglomerates 


Undivided Cretaceous marine sedimentary rocks 
graywacke (sandstone), shale, conglomerate 


Upper Cretaceous marine sedimentary rocks 

mudstone, shale, graywacke (sandstone), conglomerate 


Lower Cretaceous marine sedimentary rocks 
shale, siltstone. sandstone, conglomerate 


Upper Jurassic to Upper Cretaceous rocks 

Franciscan formation: shale, graywacke (sandstone), conglomerate, 
chert, glaucophane schist 


Mesozoic ultrabasic rocks 

mostly serpentine rocks (serpentinites) 


Jurassic and Cretaceous marine sedimentary rocks 

Knoxville formation: shale, siltstone. sandstone conglomer< 
and some limestone. 


Fault, dashed where inferred 
Contact, dashed where uncertain 
River Basin Boundary 
Sub-basin Boundary 






















Area of Major Geologic Units--Southern Basins 
( Square Miles) 


P r rf 
p 0) 
CD Ti 

£ B 

<v o 

Ph k 


P 

Cd CL> 
CD rM 

d 3 


o 

P ■H 
■H cd 
O P 
o w 
Td aJ 
a O 

CD O 


CD 

O M 
•rH cd 
bO r-H 

° ■¥, 
P £ 
O CD 
cd ra 
cO w 
< 


o 

Pc -Q 


m 


vo 


LTV 

CO 


-zt" 

CVI 


O 

CO 


i—I 

cd 

<3? 


VO 


-d~ 


CM 


CT\ 

Pt 


CO 


LTV 

CM 


CO 


CM 


1 — 1 

CP 

CO 

LT\ 

CO 

VO 

o 

1-1 

OV 

UP 

cd 

CO 

VO 

VD 

CO 

to- 

CM 

1-1 

o 

VO 

-P 

CM 

CM 

i—1 


CP 

rH 

o 

1—l 


o 





•V 





EH 





1—1 


I-1 




I-1 


OO 

t- 


VO 

CO 


CO 
t— 


vO 

vo 


CD CQ 
P -P 
•H p 
P CD 
£ 

£ -H 

"O 

CD CD 
P W 
CD 

O CD 

O P 

-P -H 
W p 
■H cd 
CD £ 

I-1 Q 

Ph O 
I P 
O 

•H T3 
r—I P 
Ph cd 


t- 

CO 


CQ 

-p 

p 

CD 


£ 

& 


£ 

Eh 


O 

CO 


to¬ 

co 

to- 


-=j" 

CO 


Pt 

I—1 

CM 


OV 

VO 




OV 

CO 


vo 

uo 


co 

CM 

fc— 


o 

CO 


CP 

-of 



1—1 
w 

Ch 

t> 

<+H 


p 

Ed 

M) 

« 

W 

W 

W 




o 


o 

o 


r—1 

J - 

o 

Pt 


co 

LTV 

Pt 


OO 

CP 

o 

CM 


LT\ 

CO 

p± 




•H 

w 



P 


c/d 



CD 







p 



O 


O 



-P 

P 





CD 

m 

o 

CD 


CD 

•H 

p 

M 

p 

m 


•rH 

P 

o ■ 

•rl 

w 


0 ) 



O 

w 

p 

p 

P> 

cd 

o 

CQ 

•rH 

p 

p 


£j 


CD 

cd 

-p 

•H 

g 

P 

o 

•rH 

rP 

P 

$ 

p 


CD 


£ 

P> 

p 

P 

p 

0 > 

1— 1 

P 

CD 

P 

£ 


cq 

o 


•rH 

CD 

CD 

cd 

o 

g 

o 

cd 

O 

CD 

P 

£ 

J 

o 


5 h 

P 

£ 

g 

<P 

•r—1 

> 

CJ 

P 

Pi 

o 

•rH 

<d 

-p 


cd 

o 

•rH 



•d 


i—I 


P 

Ch 

'Ot 

EH 

m 


g 



w 

P 

CD 

p 

o 

O 

CD 


CD 

o 

•r-\ 

c/d 


Td 

CD 

P w 

cd 

C/D 

cd 

> 

•1—1 

W 

CD 

W 

EH 

(D 

o 

>> 

CD 

ra 

o P> 

o 


CD 

cd 

c/d 


r—1 



i—1 

•rH 

Jh 



CD P 

ra 

CD 

w 

-P 

cd 

rO 

r—t 

CD 


Ph 

1 

£ 

cd 

•r—1 

CD 

CD CD 

•rH 

£ 

■rH 

o 

rO 

i—1 

•1—1 

P 


cd 

•i—i 

> 

P 

cd g 

o 

•rH 

CD 

£ 

cd 

P 

t> 

•rH 


o 

O 

p> 

•i—1 

•H 

-P -H 

P 

u 

P 


?H 

ra 

X 

P 


•H 

i—I 

p 


P 

CD TP 

cd 


cd 

-P 

O 

o 

£ 


i—1 

o 

CD 

d 

cd 

P CD 

P 


P 

P 

r—j 

£ 

p 

£ 


Ph 

> 

EH 

13 

£ 

O CQ 

Ph 


Ph 

cd 

13 

s -^ 


v -^ 



9 





















and chart: and many more fossils; it is also much less structurally 
deformed and much more regularly bedded. 

Tertiary rocks outcrop in an area west of the San Andreas Fault and in 
small isolated areas near the coast. Generally, the Tertiary rocks are 
of marine origin and consist of sandstone, siltstone, and conglomerate. 
Sedimentary and volcanic rocks of younger age occur near Santa Rosa and 
around Clear Lake. 

Erodibility of the various broad geologic formations or assemblages is 
variable and depends upon many factors such as mineralogy, degree of 
weathering, and structural history. Generally, the Franciscan formation 
is highly unstable, largely because of the presence of both small and 
very large faults and shear zones often hundreds of feet wide. The 
deeply weathered Franciscan formation contains shale interbedded with 
more massive rocks, and serpentinite is common. These inherently weak 
structural features, combined with high rainfall, prolonged storms, 
high peak flows, and rugged terrain, account for the widespread insta¬ 
bility and erodibility of the Franciscan formation. Consequently, land¬ 
slides, streambank erosion, and soil creep are common. In contrast, 
the volcanic rock in the Clear Lake and Russian River Basins Is relatively 
stable and produces very little sediment from mass erosion processes, 
such as landslides and streambank erosion. 

A commercial steam field is located within the Russian River Basin on 
the upper reaches of Big Sulphur Creek in an area known as The Geysers. 
This area remains an attraction as a spa. The Pacific Gas and Electric 
Company of San Francisco is developing the area and has been producing 
power from steam wells since i 960 . The Geysers area is unique in that 
it is the only steam field outside of Italy which produces dry steam, 
and it is the only field in the United States sufficiently developed 
to produce electric power. 

NORTHERN BASINS 

The basins contain a complex array of rock types, including volcanics 
in the eastern part, older deformed and metamorphosed sedimentary and 
intrusive rocks in the central or mountainous part, and softer folded 
and faulted rocks of the Franciscan formation in the western coastal 
region. Ages range from Silurian or possibly older (300-400 million 
years) to recent sediments. About 20 percent, or 2,100 square miles, 
of the basin is underlain by intrusive rocks, such as granite, peridotite, 
and serpentinite. Young volcanic rocks cover another 25 percent, or 
2,700 square miles, and about 37 percent, or 3,900 square miles, is 
underlain by older metamorphosed rocks. The Franciscan formation and 
unnamed Jurassic sediments and metasediments underlie about 12 percent 
of the basins. The remaining 6 percent is underlain by recent sediments, 
such as stream and lake deposits and Pleistocene terraces. The General¬ 
ized Geologic Map and the table "Area of Major Geologic Units" are shown 
on the following pages. The map shows the extent of these rock types, 
and the table shows a detailed breakdown of the various rock types shown 
on the map. Erodibility varies across the basin. The Franciscan forma¬ 
tion, which outcrops in the western part of the basin, is easily eroded, 


10 


M7-S-2I456-N 


LEGEND 



Ool 

01 


Ouoternory alluvium ond dune sand 

Quaternary lake deposits 

cloy, volconic osh, dlotomite, sand 


8 

I 


. 



GENERALIZED GEOLOGIC MAP 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 


NOVEMBER 1971 

5 0 5 10 IS 20 MILES 


Pliocene-Pleistocene non-marine sedimentory deposits 
cloy sand,gravel, sondstone, conglomerate 
(includes minor morlne terrace deposits) 

Ouoternory-Tertiory volconic rocks 

basaltic, andesitic, and rhyolitic flows, dikes, tuffs, ond volconic ejecto 

Upper Cretoceous morlne sedimentory rocks 

Hornbrock Formation-orkosic sondstone, conglomerate, shale 

Fronciscon Formation 

groywocke(sondstone),shole, chert, oltered volcanic 
rocks (greenstone), minor conglomerate 

Mesozoic gronitic rocks 

Mesozoic bosic intrusive rocks 

hornblende gobbro, gobbro, dork dlorite 

Mesozoic ultrobasic intrusive rocks 

pyroxenlte, dunite, peridotlte, serpentinite 

Upper Jurossic morine sedimentory ond metosedimentory rocks 
Golice Formation-slote,phyllite, tuffaceous sondstone 
(includes minor Jurassic and/or Trlossic metavolconic rocks) 

Undifferentloted pre-Cretoceous metomorphic rocks 
(includes some ms ond mv) 
phyllite,quartzite, chert,morble, metovolcanics 

Pre-Cretoceous metosedimentory rocks 

quortzite, phyllite, metochert,quortz-mico schist 

Pre-Cretoceous metovolconic rocks 
greenstone,omphibolite, diobose 

Poleozoic sedimentory ond metomorphic rocks 

mudstone,shole,sondstone, conglomerate, limestone, 
tuff, greenstone,hornblende schist, quortz-mico schist 

Contoct 

Foult; doshed where inferred 

Bosln Boundory 

To be included in Finol Report for North Coostol Areo 


SCALE 1-1.2 


















ft ft 
q nj 
CD ft 

o q 
q p 

<L> O 

ft ft 


CVJ 


cn 


lca i—l _q- On 

CVI 


CA CO 


CO 


ft - 


ft - 


I—I 

I—1 


o 

o 

I —I 





i—1 

UA 

00 

1—1 

UA 

CVI 

o 

OO 

VO 

LTV 

o 

1—1 

f—1 

ft 

CA 

UA 




cd 

CA 

1—1 

VO 

b- 

-3- 

CO 

VO 

CA 

i—1 

1—1 

CO 

LT\ 

CO 

1—1 

CA 




ft 

1—1 

on 


vo 


ft 

CA 


o 

C\ 

ov 

ft 

ft 

CVJ 

b- 




o 




r\ 





CN 





•N 

CN 




EH 




CVI 





1-1 


1—1 



1—1 

o 

1—1 

C/2 



ft 

P 
















£h 

•i—1 



CA 


o 



o 

o 


IP 

ft 





o 

co 



•H 

CVJ 

1 

cvi 

1 

1 

VO 

CVI 

1 

b- 

CO 

1 

1 

1 

1 

On 

cd 



a 






1—1 



CVJ 

CVJ 





b- 

ft 



CO 
















q 


q 

















q 


•i—1 

>3 
















CL) 


W 

P 











CA 



CA 

CA 

p 


cd 

•H 







CO 

cvj 

00'. 

cvi 

1—1 

1—1 

P 


ft 

£ 

1 

1 

1 

1 

1 

CVJ 

1—1 

b- 

E 

CO 

OV 

o 

CO 

VO 

VO 

q 


•H 






ft 


CVJ 

cvj 

ON 

CVJ 


VO 

OV 

o 


q 

q 















•A 

ft 

^—~a 

CD 

EH 















cvj 

i 

C/2 

!> 

















co 

-P 

CD 

_i 

•rH 

ft 

ft 

P 
















i—1 

g 

VO 

00 

1—1 

LTV 

OJ 

VO 

LTV 

ft 

o 

ft 

CcJ 

o 

CO 

o 

VO 

•i—1 


cd 

VO 

1—1 


b- 



OO 

CVJ 

VO 

OV 

CO 

ua 

LTV 

UA 

CO 

q 



a 

1—1 

on 

VO 


CVJ 

LTV 


p 

CO 

CA 

cvj 

CO 

UA 

o 

ft 

CL) 


cd 




*n 











CN 


q 


1—1 




CVJ 











o- 

O 

cc5 


ft 

















2. 

bD cd 

O CO 


1-1 V—X* 














C/2 






o 














O 






CD 

c> 














•i—1 

p 















--—- 


CD 


ft 






u 










o 


P 


q 






o 










q 


•rH 


o 

CO 

CO 




•rr) 










ft 

co 

q 

CO 

a 

p 

o 














ft 

CD 

<D 

p 

cd 

q 

■H 

P 











q 


cd 

!> 

X 

q 

p 


q 








co 



o 


bO 

•i—1 

o 

CD 

CD 

a 

cd 

q 



4h 





P 



•rH 



co 

q 

a 

a 

•rH 

o 

cd 



o 





q 



p 



P 

b3 

•rH 


p 

i —1 









0) 


co 

cd 


co 

q 

ft 

ft 

p 

CD 

o 

co 



cd 





a 


P 

a 


0) 

p 


CD 

CD 

co 

> 

P 



CD 





•i—1 

co 

q 

q 

co 

> 

q 

•N 

co 

P 

p 

p 

q 


c/2 

U 




C/2 

ft 

ft 

CD 

o 

P 

•rH 

•rH 

0) 


cd 

CD 


ft 

< 


CD 


-P 

(D 

o 

a 

p 

CJ 

co 


P 

CD 

•rH 

CD 

CD 

a 

C/2 

< 


bD 


■f—i 

CO 

o 

•i—l 


o 

P 

o 

•rH 

q 

P 

CO 

CO 

•rH 

O 

EH 


O 

aJ 


co 

q 

ft 

q 

q 

q 

•i—1 

q 

•1—1 

q 

o 

O 

P 

• i—1 

o 


•i—l 

i—1 


O 

(D 


CD 

cd 


p 

C/2 

•rH 

q 

CD 

p 

P 

CD 

P 

EH 


bD 

,£2 

g 

ft 

q 

o 

CO 

o 

o 

q 

cd 

P 

cd 

q 

ft 

ft 

co 

ft 



O 

£3 


CD 

•rH 

•rH 


co 

•rH 

•rH 

rO 

q 

a 

CD 

q 

q 

p 

q 



1-1 

CD 

•rH 

o 

q 

q 

CD 

• rH 

p 


1 

CD 


ft 

o 

g 

o 



o 

C/2 

i> 



cd 

q 

o 

•i—1 

o 

cd 

ft 

q 

ft 

a 

a 

co 

a 



(D 

C/2 

P 

CD 

o 

•rH 

q 

q 

•i—1 

Jh 

q 

CD 

•rH 

cd 

cd 

CD 

cd 




< 

I—1 

ft 


I—1 

q 

cd 

cd 

C/2 

-P 

CD 

ft 

ft 

P 

P 

P 

P 




l—1 

cd 

o 

o 


q 

q 

cd 

r— 1 

co 

1—1 

q 

ft 

ft 

i—1 

g 





< 

ft 

ft 

> 


ft 

co 

PQ 

& 

—" 

o 

ft 

S 

S 

O 

a 



ft ft 

1 — 1 


o 

> 


ft 


cd a 

cd 

i — 1 

ft 

EH 

3 

ft 

q 


G? 

<3? 

<3? 

C3? 

ft 

ft 

bD 


CO 


£ 


t> 

a 


ft 


11 



















and some metasedimentary rocks (m, ms on geologic map) are extremely 
erodible when disturbed. Important outcrops of these rocks are found 
in the South Fork, Lower Trinity, and Middle Klamath Subbasins. Volcanic 
rocks in the Butte Valley-Lost River and Shasta Valley Subbasins are very 
resistant to erosion. 

Four episodes of glaciation have been recognized in the Trinity Alps. 
Evidence of past glaciation in the high mountainous areas includes 
U-shaped valleys, cirques, glacial lakes, and moraines. Glacial 
deposits along the valley sides (lateral moraines) are composed of sand, 
gravel, and boulders and are easily eroded. As a consequence, large 
quantities of boulders and gravel, derived from the moraines, have been 
eroded and redeposited downstream. Examples of such gravel deposits 
can be found along Swift Creek and Union Creek in the Trinity Alps and 
along Kidder and Canyon Creeks in the Marble Mountains. 


SOILS 


Information from soil surveys was utilized and supplemented by a gener¬ 
alized soil map of most national forest lands. 

Several hundred phases of about 200 soil series and miscellaneous land 
types were combined into 92 soil associations for the river basin study 
of the North Coastal Area. Soil association names were derived from 
soil series names. The distribution of the soil associations is shown 
on the General Soil Maps and in the tables "Approximate Area of Soil 
Associations" on the following pages. 

Detailed data on soils is presented in the Addendum to this appendix; 
included are the tables "Soil Characteristics, Qualities and Interpre¬ 
tive Groupings," interpretive maps, and definitions. 

SOUTHERN BASINS 

The dominant soils of these basins -- the Russian, Mendocino Coastal, 
and Clear Lake -- are in the Hugo and Josephine series, which comprise 
about 47 percent of the area. Both have loam or gravelly loam surface 
textures, but the Josephine soils have a higher clay content in the sub¬ 
soils. They are from 30 to 60 inches or more in depth over fine-grained 
sandstone, and are used mainly for commercial timber production. Slope 
gradients range from 0 to 75 percent. 

Laughlin soils cover 12 percent of the basins and occur on 30 to 50 
percent slopes. They generally support grass, forbs, oak, and 
manzanita and are principally used for grazing. These soils have a loam 
surface and sandy clay loam subsoils underlain at depths of 20 to 40 
inches by sandstone or shale. 

The shallow Maymerj. and Henneke soils, which comprise about 12 percent of 
the Southern Basins, average 10 to 20 inches deep over parent material. 
Maymen soils are underlain by shattered hard sandstone, and Henneke soils 


12 



by serpentine. Slopes range from 9 'to 75 percent. Gravelly loam or 
gravelly sandy loam surface textures characterize these soils; the 
Henneke soils have a very gravelly clay subsoil. The vegetal cover 
consists of manzanita, chamise, oaks, and small shrubs, with an under¬ 
story of grasses and forbs. The soils are located on 9 to 75 percent 
slopes and are mainly used for watershed and wildlife habitat. 

Soils of the valleys and terraces make up about 20 percent of the basins. 
These soils are quite variable as to surface and subsoil texture, depth, 
drainage, and other properties. They usually occur on slopes of less 
than 9 percent and are mainly used for cropland and pasture. The remain¬ 
ing 9 percent of the soils are generally steeper than 30 percent and 
rocky. They are used mainly for woodland, wildlife, and watershed. 

NORTHERN BASINS 

About 60 percent of the basins consists of soils that normally support 
timber, such as Sheetiron, Masterson, Hugo, Josephine, Boomer, and Neuns 
series soils. Slopes range from 0 to 75 percent. All except Boomer and 
Neuns are formed from sandstone and shale and have gravelly loam surface 
soils, with bedrock at 30- to 60-inch depths. The Boomer and Neuns soils 
have gravelly, sandy loam surface soils over gravelly clay loam subsoils. 
Bedrock usually occurs between 40 and 60 inches deep. 

About 20 percent of the area is made up of rock land or lava flows 
intermingled with very shallow to moderately deep members of the Yolla 
Bolly, Windy, Dubakella, and similar series. The vegetal cover is 
generally sparse, consisting of grasses and forbs, shrubs, oaks, and 
mixed conifer. 

Cultivated areas near the coast, about 0.5 percent of the area, are 
confined mostly to the Ferndale and Timmons series. Both are used for 
pasture, and although both are highly suited for redwood growth, only 
the Timmons now has redwood stands. These soils are well drained, very 
deep, and have loam or silt loam textures. 

The major portion of the soils used for cultivation and some pasture or 
grazing occur in the Klamath Basin. These soils comprise about 20 per¬ 
cent of the area. They are members of the Bieber, Modoc, Stoner, Green¬ 
horn, and similar series. These soils have a variety,of characteristics, 
ranging from gravelly sandy loam through loam to clay loam surface 
textures, with slopes mainly from 0 to 9 percent. Most are moderately 
deep to deep. Some, such as the Modoc, have hardpans that occur at about 
3 feet; in the Bieber the hardpan occurs at about 2 feet. These soils 
are mostly used for irrigated or dry pasture, grain, and hay. 


13 







Approx-hna lux Area of Soil Associations--Southern Basins 


fiol 1 

A HO' 1 at Ion 
f Ni imbe r) 



Area (Squm 

v Mllia) 



Percent of 

Total Area 

So 11 Ab hoc 1 a tIona 
(Name) 

Ru s s 1 an 

Basin 

Mrndocino 

Coastal 

Basins 

Clear Lake 

Basin 

Total 

1 



95 


95 

2-'. 

2 

Larabee - Mendocino - Caspar association, 30 to 50 percent slopes 


20 

_ 

20 

0.5 

3 

Hugo - Josephine association, 0 to 30 percent slopes 

30 

85 

- 

115 

2.8 

4 

Hugo - Josephine association, 30 to 50 percent slopes 

120 

645 

55 

820 

20.5 

5 

Hugo - Josephine association, 50 to 75 percent 

U5 

gflfl 


9^5 

ji.h 

8 

Kneeland association, 9 to 50 percent slope s 


15 


IS 

n.9 

9 


. 

20 

. 

20 

0.5 

10 

Yorkville association, 15 to 50 percent 6lope6 

50 

55 

. 

105 

2.6 

11 

Laughlin association, 0 to 30 percent slopes 

40 

10 

40 

90 

2.2 

12 

I.aughlin association, 30 to 50 percent slopes 

2 30 

75 

- 

305 

7.5 

13 

Laughlin association, 50 to 75 percent slopes 

50 

25 

- 

75 

1.8 

15 

Henneke association, 9 to 50 percent slopes 

55 


10 

65 

1.6 

16 

Maymen - Los Gatos association, 15 to 75 percent slopes 

215 

55 

160 

430 

10.7 

17 

Boomer association, 30 to 50 percent slopen 

15 

- 

- 

, 15 

0.4 

18 

Roomer association, 50 to 75 percent slopen 

10 

5 


15 

0.4 

19 

Colluvial land - Landslide association, 9 to 75 percent slopes 

10 

1 5 


25 

0.6 

24 

Wilder association, 15 to 50 percent slopes 


10 


10 

0.2 

26 

Dune land - Coastal beaches association, 0 to 30 percent slopes 


5 


5 

0- 1 

29 

Yolo - Zamora association, 0 to 2 percent slopes 

30 


20 

50 

1.2 

30 

Fcrndnlc - Russ association, 0 to 9 percent slopes 

_ 

10 


10 

0.2 

33 

Carlotta - Ettersburg association, 0 to 5 percent slopes 

- 

10 


10 

0. 2 

34 

Riverwash - Alluvial land association, 0 to 9 percent slopes 

10 

8 

3 

■21 

0- 5 

35 

Cole - Clear Lake association, 0 to 2 percent slopes 

- 

- 

25 

25 

0. 6 

36 

Pinole - Talmage association, 0 to 9 percent slopes 

45 

5 


50 

1.2 

37 

Noyo - Blecklock assoicatlon, 0 to 30 percent slopes 


40 

_ 

40 

1.0 

38 

Maywood - Zamora association, 0 to 5 percent slopes 

35 

10 

- 

45 

1 .1 

39 

Areata - Rohncrville association, 0 to 9 percent slopes 

- 

40 

- 

40 

1.0 

42 

P.ijnro association, 0 to 2 percent slopes 

.5 


15 

zn 

o ^5 . 

4 1 

Colliding - Toomee association, 9 to 30 percent slopes 

30 



30 

0.7 

44 

Forward - Kidd - Rock land association, 30 to 75 percent slopes 

15 

- 


1 5 

0.4 

46 

Sp reck 1e 6 - Felta association, 15 to 50 percent slopes 

50 

- 


50 

1.2 

47 

Goulding - Toomea association, 30 to 50 percent slopes 

40 

- 

- 

40 

1.0 

48 

Cotati association, 2 to 9 percent slopes 

10 

- 

f 

10 

0.2 

49 

Goldridge association, 2 to 15 percent slopes 

40 

15 

- 

55 

1.4 

51 

Huichica - Wright association, 0 to 9 percent slopes 

55 

- 


55 

1.4 

52 

Clear Lake association, 0 to 2 percent slopes 

25 

- 


25 

0.6 

53 

Suther - Yorkville association, 15 to 50 percent slopes 

40 

5 

5 

50 

1.2 

55 

Pinole - Manzanita association, 2 to 9 percent slopes 

- 


30 

30 

0.7 

56 

Yolo*- Cortina - Pleasanton association, 0 to 2 percent slopes 

85 

- 

- 

85 

2.1 

57 

Sobrante association, 15 to 50 percent slopes 

- 

- 

10 

10 

0.2 

58 

Konokti - Pluth association, 30 to 75 percent slopes 

- 

- 

35 

35 

0.9 

59 

L-sse - Glenview association, 15 to 50 percent slopes 

- 

- 

10 

10 

a 2 

60 

Cohasset - Red Hill association, 0 to 30 percent slopes 

- 

- 

35 

35 

a 9 

62 

Phipps - Soper association, 15 to 50 percent slopes 

. 


5 

5 

0. 1 

Total 


1485 

2098 

4 58 

V 

4041 

100.0 


1 / 

—■ Does not include Clear Lake - 68 square miles. 


14 







































































BASINS 





GENERAL SOIL MAP 

SOUTHERN RIVER BASINS 

HUMBOLDT, LAKE, MENDOCINO, AND SONOMA COUNTIES, 
CALIFORNIA 

NOVEMBER 1971 


































GENERAL SOIL MAI 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 


NOVEMBER 1971 



























Approximate Area of Soil Associations--Northern Basins 


Soli 

Association 

(Number) 

Soil Associations 
(Name) 

Area (Square Miles) 

Percent o f 
Total Area 

Klama th 

Ba6in 

Trinity 
Basin 

Smi th 

Basin 

Total 

4 

Hugo-.loseph ine association, 30 to 50 percent slopes 

70 

95 

120 

285 

2.7 

5 

Hugo-Josephine association, 50 to 75 percent slopes 

220 

5 

30 

255 

2.4 

6 

Shoetiron-Masterson-Hugo association, 30 to 75 percent slopes 

700 

370 

250 

1,320 

12.2 

18 

Boomcr-Nuens association, 30 to 75 percent slopes 

600 

1,120 

65 

1,785 

16. 5 

20 

Yol 1 r.bo 1 ly - Rock land association, 30 to 75 percent slopes 

140 

85 

- 

225 

2.1 

10 

iVnulale association, 0 to 9 percent slopes 

10 

5 

20 

35 

0.3 

63 

Fordney-Poe association, 0 to 2 percent slopes 

140 

- 

- 

140 

1.3 

64 

Tulnna-Algomn association, 0 to 2 percent slopes 

100 

- 

- 

100 

0.9 

65 

Chawanakoc-Corbctt-Siskiyou association, 15 to 75 percent slopes 

300 

275 

- 

57 5 

5.3 

66 

Dubakella-Ishi Pishi-Weitchpec association, 9 to 50 percent slopes 

400 

175 

240 

815 

7.6 

67 

Kinkel-Boomer association, 15 to 50 percent slopes 

300 

- 

- 

300 

2.8 

68 

Kinkel-Boomer-Duze1 association, 0 to 50 percent slopes 

400 

- 

- 

400 

3.7 

6'i 

Jo- •pliiiii'-.';: i rii-M'iy""'" /irt.-.ucluL Ion, 9 to 30 percent alopuK 

- 

390 

- 

390 

3 . <> 

70 

Tournqu i sr-Fortola association, 0 to 50 percent slopes 

3 50 

- 

- 

350 

3.3 | 

71 

Tyson-Cahto association, 30 to 50 percent slopes 

80 

- 

- 

80 

0.7 

72 

Woodstock-Pokegama association, 15 to 50 percent slopes 

150 

- 

- 

150 

1 .4 

73 

Windy-Lava flows association, 15 to 75 percent slopes 

200 


- 

200 

1 .8 

74 

Tournquist association, 0 to 9 percent slopes 

250 

- 

■ 

2 50 

2.3 

75 

Tournquist-Merlin association, 0 to 9 percent slopes 

200 

- 

- 

200 

1.8 

76 

B1ebcr-Salisbury-Modoc association, 0 to 9 percent slopes 

180 

- 

- 

180 

1 .7 

77 

Stoner-Grtenhorn-Serpn association, 0 to 5 percent slopes 

160 

- 

• 

160 

1 . 5 

78 

Nevndor-Ocho association, 0 to 5 percent ulopen 

110 

- 

- 

no 

1.0 

79 

Pu1s-Made 1ine association, 0 to 9 percent slopes 

350 

- 

- 

350 

3.3 

80 

Delaney-Plutos association, 0 to 30 percent slopes 

70 

- 

- 

70 

0 - 6 

81 

Pasquetti-Ramclli association, 0 to 9 percent slopes 

10 

- 

- 

10 

0.1 

82 

Shasta association, 0 to 50 percent slopes 

50 

- 

. 

50 

0.5 

83 

Lassen-Kuck-Mary association, 0 to 50 percent slopes 

250 

- 

- 

250 

2.3 

84 

Crebbln association, 0 to 2 percent slopes 

50 

- 

- 

50 

0.5 

85 

Salisbury -Monlague-Louie Association, 0 to 9 percent slopes 

120 

- 

- 

120 

1 . 1 

86 

Rock land association, 0 to 75 percent slopes 

60 

- 

- 

60 

0.6 

87 

Gerig association, 0 to 15 percent slopes 

250 

- 

- 

2 50 

2.3 

88 

Kilarc-Plumas association, 0 to 30 percent slopes 

* 

25 

- 

25 

0 .2 

89 

Timmons association, 0 to 15 percent slopes 

- 

- 

35 

35 


90 

Ctuqulto-Rjck land Corbett association, 30 to 75 percent slopes 

210 

125 

30 

365 

3.4 

91 

Windv-Rock land association, 15 to 75 percent slopes 

270 

270 

- 

540 

5.0 


I »va flows association, 0 to 30 percent 

155 

- 

- 

155 

1.4 

Sub Local 


6,905 

2,940 

790 

10,635 

98.5 

Wa ier 


131 

29 

- 

160 

1.5 

Total 


7,036 

2,969 

790 

10,795 

100.0 


15 





















































VEGETAL COVER TYPES 


The following tabulation summarizes the current areas of vegetal cover 
types and areas where original vegetal cover has been modified, such as 
cropland and urban and water development areas. The Vegetal Cover Types 
Maps for the basins appear on the following pages. 


Current Land 

Cover 

Area 

Northern 

Basins 

(Square Miles) 

Southern 

Basins Total 

Percent Of 
Total Area 

Conifer 

4,46oi/ 

1,160 

5,620 

38 

Woodland 

2, lOOi/ 

875 

2,975 

20 

Grass 

1,07°, 

620 

1,690 

11 

Woodland-Grass 

520 2/ 

165 

685 

5 

Brush (Shrub) 

1,990 

680 

2,670 

18 

Cropland 

390 

360 

750 

5 

Other (Barren, Water, 
Urban-Indus tria1, 
etc. ) 

265 

249^/ 

514 

3 

Total 

10,795 

4,109 

14,904 

100 


— Maps for this area were unavailable or insufficiently detailed to 

separate woodland from conifer; data represents an estimated proportion 
of 6,560 square miles of conifer-woodland. 


2 / 

Data represents an estimated proportion of juniper-grassland among 
1,590 square miles shown as grassland on the Vegetal Cover Types Map. 


3/ 


Includes Clear Lake (68 square miles). 


Coniferous forest is composed of several cover types, the most important 
of which are redwood, redwood--Douglas-fir, mixed conifer (mainly Douglas- 
fir, true firs, and sugar and ponderosa pine), and pure ponderosa pine. 
Respectively each lies further from the coast and each receives progres¬ 
sively less precipitation. Minor conifer species, such as Sitka spruce, 
various cypresses, Port Orford cedar, coast and mountain hemlock, lowland 
fir, incense cedar, canoe cedar, juniper, and Bishop and knobcone pine, 
are found in various locations, depending mostly upon soil-moisture 
relationships. Broadleaf trees, typical of which are tan oak, alder, 
madrone, and toyon, grow interspersed in patches throughout the conifer 
stands. Ferns, rhododendron, azalea, salal, thimbleberry, huckleberry, 
and other shrubs often form a rather luxuriant undergrowth in forests 
near the coast while, inland, both species and density of underbrush 
vary widely. 

Woodland , as used here, is a collective term for broadleaf trees and 
includes both deciduous and evergreen species. California black oak, 
Oregon oak, alder, dogwood, Oregon ash, bigleaf maple, and buckeye are 


16 


















VEGETAL COVER TYPES 
SOUTHERN RIVER BASINS 

s HUMBOLDT, LAKE, MENDOCINO, AND SONOMA COUNTIES. 

? CALIFORNIA 

rs> NOVEMBER 1971 


MENDOCINO 
COASTAL 

O 

o 


□ « 

HT 
































VEGETAL COVER TYPES 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 


SMITH 

BASIN 


SCALE 1:1,250,000 


20 MILES 
















the most common of the deciduous species, while tan oak, live oak, 
inadrone, bay, and toyon are the most representative of the evergreens. 
Typically, evergreens predominate near the coast, and in the inland 
mountainous zones deciduous trees are most prevalent. Poison oak, 
manzanita, various Ceanothus, scrub forms of various oaks, currant, 
raspberry, blackberry, annual grasses, and forbs form the understory. 

The grass type is made up of a variety of herbaceous species, predom¬ 
inantly annuals. Typical herbaceous species are oat grasses,.various 
bromes, wild barleys, fescues, wild oats, filaree, Medusahead, and 
burclover. The Modoc Plateau contains meadows that receive subterranean 
moisture where perennials, such as sedges and rushes, are found. In 
the uplands of the Modoc Plateau, low shrubs, such as rabbit brush, 
horsebrush, and sagebrush, are included. 

The woodland-grass type is a combination of the two types described in 
the immediately preceding paragraphs. In parts of the study area, 
mostly in the Southern Basins, much of the landscape is savannah covered 
by low annuals with an occasional large single tree or scattered groups 
of trees. California black oak and live oak are the most common trees; 
vegetation in the open areas is grass and other herbaceous annuals. 

The brush type, called chaparral, consists of species that range in 
height from three to twelve feet, generally with rigid branchlets and 
thorny projections. These often form dense thickets that are virtually 
impenetrable to all but birds and rodents. Along the coast, blueblossom 
Ceanothus, rhododendron, and azalea are the most common species and, in 
the spring, these present brilliant wildflower displays. Inland, chaparral 
usually occupies seasonally hot sites, and typical species are manzanita, 
various Ceanothus, chamise, scrub deciduous and live oaks, poison oak, 
baccharis, and Yerba Santa. On the more xeric timber sites, the shrub 
species tend to encroach on timber sites that have been burned or logged. 
Pure stands of a single species are common, and individual scattered 
digger pine occur in fringe areas that adjoin conifer or woodland types. 

On the Modoc Plateau, open stands of small juniper, bitterbrush, mountain 
mahogany, horsebrush, rabbit brush, sagebrush, and various forbs are the 
predominant species. 

Cropland includes both irrigated and non-irrigated land and is located 
mostly in the river valleys scattered throughout the study area. The 
non-irrigated and much of the irrigated lands are generally used for 
hay production and pasture and are covered mainly by grasses. The other 
irrigated areas support orchards, vineyards, and grain and row crops. 

The remaining land, shown in the "Other 1 ' category, is a combination of 
types that support little or no vegetal cover. Barren areas occur on 
mountain tops, rocky and sandy coastline, rock outcrops, and similar 
sites where soil and climate conditions limit vegetal growth. Some 
of the most spectacular scenery is in this category. Watersurface areas 
include lakes and reservoirs. Urban and industrial areas usually support 
considerable vegetation, but it is often different from the original 
natural cover. 


17 












LAND IJ£JK 


I^ndr; arc often used ['or multiple purposes, but were categorized accord- 
in/- to the principle use. The following tabulation shows the approximate 
present land use pattern. 

Area (Square Miles) 


Land Use 

Northern 

Basins 

Southern 
Basins 

Total 

Percent Of 
Total Area 

Timber Production 

5,072 

1,216 

6,288 

42 

Grazing 

2,093 

1,666 

3,759 

25 

Irrigated Cropland 

273 

240 

513 

3 

Non- T rrigated Cropland 

121 

117 

238 

2 

Urban and Industrial 

8 

43 

51 

<1 

Designated Recreation 

200 

22 

222 

2 

Designated Wilderness 

726 

0 

726 

5 

Designated Fish and 
Wildlife 

251 

158 

409 

3 

Miscellaneous Use 

2,051 

647 

2,698 

18 

Total 

10,795 

4,109 

14,904 

100 


The economy of the basins is tied directly to the productivity and 
utilization of the land resources. Timber, agriculture, and recreation 
rank in that order as the three most important segments of the economy; 
others include mining, manufacturing, power production and transmission, 
transportation, and services. 

TIMBER PRODUCTION 

The timber industry developed with the settlement of California's North 
Coast and quickly became the most important industry and accounts for 
most of the income and employment. The Northern Basins are almost 50 
percent forested, while the Southern Basins are about 30 percent forest¬ 
ed. In both cases, a large share of this land is dedicated to the 
production of timber. Most of the early timber harvest was simply an 
exploitation of the resource with little regard for the future, and much 
of the land in small ownerships continues to be managed that way. 
Recently, some private owners, particularly those holding large acreages, 
have shifted to sustained yield management, similar to a type of manage¬ 
ment long used on national forest timberlands. 


l8 














About 3 percent of the commercial timberland acreage is logged each 
year, including the harvest of sawlogs and poles and products of thin¬ 
ning operations. Production per acre is generally superior to other 
timbered areas in the State. 

About 200 square miles of timberland have been converted to grass for 
grazing. Recently, the number of new conversions has decreased, and 
some previously converted areas are being allowed to revert to timber. 

A small net loss in timber producing lands is expected as recreation, 
urban, summer home, water development, roads, and other uses increase. 
Areas set aside for parks, wildernesses, or as part of a wild and scenic 
rivers program will also eliminate or modify the use of some areas for 
timber production. 

CROPLAND 

The major areas of irrigated cropland are widely scattered throughout 
the basins in the flood plains of the main rivers and along the Pacific 
Coast. These areas occur mainly around Tulelake and in the Shasta and 
Scott Valleys in the Northern Basins, and along the coast and inland 
near Santa Rosa and Clear Lake in the Southern Basins. Non-irrigated 
croplands generally occur in fringes around the irrigated lands. 

Much of both the irrigated and non-irrigated cropland is used for pasture 
and the production of hay. In addition, other crops are produced as 
follows: 


Coastal Zone - Nursery flower stock and bulbs. 

Russian and Clear Lake Basins - Apples, pears, prunes, 
walnuts, and grapes. 

Shasta and Scott Valleys - Grain crops and potatoes. 

Butte and Tulelake Valleys - Potatoes and onions. 

The area of irrigated cropland is expected to increase in the future 
despite a steady, but slow, encroachment by urban and other development. 
Non-irrigated cropland acreage will decrease because much of it will be 
irrigated as new sources of water are tapped and more intensive develop¬ 
ment occurs. 

GRAZING 

Grazing of cattle and sheep was one of the earliest land uses in the 
basins and is still economically important. In the Northern Basins, 
this consists of fall, winter, early spring, and late summer pasturing 
on valley ranches and late spring and early summer grazing on mountain 
sideslopes. Often the latter is by permit on public lands, mainly 
national forest. 

In the Southern Basins, most private rangelands are grazed as soon and 
as long as forage is available. Much of the natural forage responds to 


19 





winter rains and reaches its peak in late spring or early summer. After 
this period, stock on annual ranges must be moved to pastures, fed 
supplementally, or sold. Ranges near the coast are grazed yearlong 
because the cooler, more humid climate and the higher percentage of 
perennials tends to sustain forage growth. Other areas, such as the 
hills west of Santa Rosa, are also grazed yearlong where good manage¬ 
ment and a high percentage of perennials makes such use possible. The 
acreage of grazing land is expected to decrease as increased regional 
populations create demands for other land uses, such as recreation and 
summer home sites. 

RECREATION 

About 220 square miles in the basins are devoted to recreation uses, and 
these are becoming more important, both in economic impact and effect 
upon other land uses. Recreation development and use occurs on both 
public and private lands. General recreation use -- camping, fishing, 
hiking, and hunting, etc. -- is more prevalent on public lands, while 
specialized uses -- organization camps, summer homes, and hunting 
and fishing clubs, etc. -- are more common on private lands. Federal 
lands provide most of the recreation opportunities in the Northern 
Basins, while in the Southern Basins, private lands and state and 
municipal parks satisfy the bulk of the demand. The area has a tre¬ 
mendous recreation potential, and an increasing regional population, 
higher income levels, and increased leisure time are expected to 
contribute to a continued buildup in recreational activity. 

WILDERNESS 

About 726 square miles of wilderness-type areas are located in the North¬ 
ern Basins, as shown in the following tabulation: 


Area 


Jurisdiction 


Approximate Area 
(Square Miles) 


Marble Mountains Wilderness-!/ Klamath NF 


335 


Yolla Bolly-Middle Eel 
Wilderness 


Mendocino and 
Shasta-Trinity NF 



Salmon-Trinitv Aims 
Primitive 



Shasta-Trinity and 
Klamath NF 



Lava Bed National Monument 


National Park Service 



Other 


Mainly National Park 
Service 


15 


Total 


726 


20 







Wildernesses are classified under the National Wilderness Preser¬ 
vation Act of 1964. 


1 / 


4-/'Area within the study basins only, 
square miles. 


Total wilderness is about 170 


^/primitive Areas are under study for inclusion in the Wilderness 
System. Acreage eventually classified may vary somewhat. 


—/Does not include 97 square miles of private land within the Primitive 
Area Boundary. 

5 / 

—'Estimated size of proposed wilderness type land within the Monument; 
remainder is counted as designated recreation. 


Several other areas physically qualify for wilderness classification, 
nearly all on public lands, so the acreage classified could increase in 
the future. 

FISH AND WILDLIFE 

About 409 square miles of land scattered through the basins are dedi¬ 
cated to fish and wildlife uses of varying intensity. Some of these 
uses limit other uses, and some do not. Included in the former class 
are three National Wildlife Refuges (Lower Klamath, Tulelake, and 
Clear Lake) in northeastern Siskiyou and northwestern Modoc Counties, 
which cover about 155 square miles. These are managed mainly to protect 
and preserve waterfowl of the Pacific Flyway, but they also provide 
fisheries and other wildlife benefits. Several fish hatcheries located 
in the basins are exclusive-use areas that occupy very little land. 

In national and state parks^fish are managed in conjunction with 
recreation use. All other Animals are protected. State Game Refuges 
also protect game but allow some other uses. These are included as 
designated wildlife areas. 

Not included as designated wildlife areas are the national forests and 
public domain lands, where the Forest Service and Bureau of Land Manage¬ 
ment, respectively, manage wildlife habitat as a part of their multiple 
use programs. In some cases, such as key deer winter ranges, special 
management programs are designed for the improvement of habitat. No 
privately owned lands are included as designated wildlife areas. How¬ 
ever, many landowners restrict hunting and fishing by limiting access or 
by allowing use only by permit. Some landowners manage game habitat to 
enhance wildlife and construct fish ponds to make their lands attractive 
to hunters and fishermen. 

It is not expected that the amount of land set aside for wildlife will 
increase greatly in the future. 


21 









Ml NINO 


Mining was one of the original industries in the Klamath and Trinity 
Basins and was responsible for the settlement of much of that area as 
well as the exploitation of many streamside zones. Extensive hydraulic 
mining and dredging and some tunnel mining were done for many years, but 
dredging and hydraulic mining are now restricted by sediment and debris 
protection limitations. 

Chief minerals presently mined include gold, chromite, quicksilver, and 
asbestos, with limited amounts of perlite, diatomaceous earth, and 
decorative rock. Many temporary gravel quarries are established each 
year in channels away from streams throughout each basin. 

Mining activity in the basins will probably maintain its present level 
except for an increase in gravel quarrying to satisfy building needs for 
increased populations. The latter will occur throughout the basins, 
while other types of mining will no doubt continue to be concentrated 
in the Klamath and Trinity Basins. 

OTHER LAND USES 

Development for urban and industrial uses has been slow, although it 
has accelerated considerably in the past few years around Santa Rosa; 
the largest and most industrialized city. Other population concen¬ 
trations are Ukiah, Fort Bragg, and Lakeport in the Southern Basins and 
Yreka, Crescent City, Weaverville, and Tulelake in the Northern Basins. 
Scattered throughout the basins are several small towns, many of them 
relics of early mining and ranching activities. It is expected that 
population growth will result in more urban-industrial development, but 
most will occur near the present population centers. Vacation home and 
resort development will probably occur sporadically in the rural areas. 

Powerlines and pipelines, which often limit other uses, span many miles. 
Power plants are located near many damsites, and a unique steam-electric 
plant is located near Cloverdale. Reservoirs preclude other land uses. 

Major railroads serving the area are the Burlington Northern, Southern 
Pacific, and Western Pacific, but none extend into the Trinity, Middle 
and Lower Klamath, or the Smith Basins. The California Western Railroad, 
which runs between Willits and Fort Bragg, is operated for sightseeing 
tours. 

Federal highways 101, 299? and Interstate 5 traverse the area and, with 
numerous state, county, national forest, and private roads, provide the 
transportation network. 

T l ie area used by roads and powerlines is expected to increase. 


22 


LAND OWNERSHIP AND ADMINISTRATION 


Land ownership and administration for the Northern and Southern Basins 
is shown on the maps on the following pages and is summarized in the 
tabulation below. 


_ Area (Square Miles) 

Northern Southern 



Basins 

Basins 

Total 

Federal Land 

Forest Service 

7,201 

46 

7,247 

Bureau of Land Management 
Bureau of Sports Fisheries 

308 

l68 

476 

and Wildlife 

2 

8 

10 

National Park Service 

ll4 

0 

ll4 

Bureau of Reclamation 

30 

1 

31 

Department of Defense 

1 

3 

4 

Subtotal (Federal Land) 

7,656 

226 

7,882 

State Land 

80 

94 

174 

Other Public Land—^ 

56 

0 

56 

Subtotal (Public Land) 

7,792 

320 

8,112 

Private Land , 

Individual & Corporate Land 

2,856 

3 , 7894 / 

6,645 

Indian Land^/ 

147 

0 

147 

Subtotal (Private Land) 

3,003 

3,789 

6,792 

Total 

10,795 

4,109 

l4 ,904 


1 / 

County, city, and special district land. 

^/includes 68 square miles of Clear Lake. 

^/includes private Indian holdings and tribal lands within the 
reservation boundaries. 


About 72 percent of the land in the Northern Basins, but only 8 percent 
of that in the Southern Basins, is publicly owned. Virtually all of the 
public land in both basins is federally owned, with only a scattering of 
state and local ownerships. 


23 


























In the Northern Basins, national forests comprise 92 percent of the 
public lands and 67 percent of all ownerships. In general, these are 
the mountainous areas that form fairly solid blocks of large holdings 
with scattered private ownerships within the national forest boundaries. 
However, in the upper Trinity and upper Klamath, east of longitude 123°, 
there is a checkerboard pattern of national forest alternating with 
other ownerships, mainly private. In the Southern Basins, only 20 per¬ 
cent of the public land is national forest, and that is confined to a 
narrow fringe on the northeast edge of the Clear Lake Basin. 

Public domain, administered by the Bureau of land Management, comprises 
about 3 percent of the land in the Northern Basins and 4 percent in 
the Southern Basins. These lands are generally consolidated blocks that 
occur in the Klamath, Trinity, and Clear Lake, and Mendocino Coastal 
Bas ins . 

About 1 percent of the public land in the Northern Basins is administered 
by the National Park Service, this includes the Lava Beds National Monu¬ 
ment in the Upper Klamath Basin and the portion of Redwoods National 
Park in the Smith and Klamath Basins. No national park land occurs in 
the Southern Basins. The bulk of the Bureau of Reclamation holdings are 
in the Upper Klamath Basin in the vicinity of Tulelake, Lower Klamath, 
and Clear Lake reservoirs. Parts of each of these reservoir areas are 
national wildlife reserves. The Bureau of Reclamation has other small 
scattered holdings, mainly in connection with water development projects. 

The Department of Defense has small, scattered holdings in connection 
with flood control projects. The Bureau of Sport Fisheries and Wildlife 
administers similar parcels for fish and wildlife purposes. 

State and local ownerships make up the balance of the publicly owned 
lands. Most of the state lands are contained in state parks scattered 
through the area and in the Jackson State Forest near Fort Bragg. Local 
holdings are mainly municipal parks and special district lands. 

In the Northern Basins, most of the private land is farm and ranch land, 
generally located in the valleys and foothills. The Simpson Timber 
Company and the Rellim Redwood Company own most of the coastal redwood 
land available for harvest, while most of the upland grazing and timber 
land is federally owned. In the Southern Basins, private ownership is 
predominant. The Boise Cascade, Georgia-Pacific, and Masonite Corpo¬ 
rations and Mo 11ala Forest Products, Inc. own large acreage of timberland, 
but considerable timberland is also contained in small ownerships. Farm 
and ranch lands account for most of the balance of the private lands. A 
relatively recent trend is the sale of small parcels, either in sub¬ 
divisions or in individual plots, for construction of both vacation and 
permanent homes. 

Included in the private holdings are l47 square miles of Indian trust 
land, located mainly in the Hoopa Reservation near the mouth of the 
Trinity River. 


24 


OWNERSHIP AND ADMINISTRATION MAP 

SOUTHERN RIVER BASINS 

HUMBOLDT, LAKE, MENDOCINO, AND SONOMA COUNTIES, CALIFORNIA 

NOVEMBER 1971 


SCALE I 760,320 


BASINS 


^ Clear Lake 
Russian River 
Mendocino Coastal 
River Basin Boundary 



FOREST SERVICE 
BUREAU OF LAND NOT. 
NATIONAL PARK SERVICE 


BUREAU OF RECLAMATION kWW'W'-l 
BUREAU OF INDIAN AFFAIRS 

WILDLIFE SERVICE [ .| 


LAND OWNERSHIP AND ADMINISTRATION 

I -- CIVIL (CORPS. OF ENO.) 

MILITARY 

ATOMIC ENERGY COMMISSION | | 

im 11 in 


STATE 

INDIVIDUAL OR CORPORATE 








































M7-N-2I6I0 


LANO OWNERSHIP AND ADMINISTRATION 


FOREST SERVICE 
BUREAU OF LANO MOT. 

NATIONAL PARK SERVICE 
BUREAU OF RECLAMATION 
BUREAU OF INDIAN AFFAIRS ITEKm INDIVIDUAL OR CORPORATE 

FISH AND WILDLIFE SERVICE 



Klamath River 
Trinity River 
Smith River 

River Basin Boundary 


OWNERSHIP AND ADMINISTRATION 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 

NOVEMBER 1971 

20^ IS jO S 0 20 40 _60 MILES 

SCALE IH,290,000 













































































PROBLEMS 


Problems presented in this chapter are those connected with sediment 
yield and land treatment and are divided into two groups -- sediment 
and debris deposition and erosion. Sediment and debris deposition 
problems normally occur with each flood. In recent years, flooding has 
occurred every third or fourth year on the average; the two major floods 
of record took place in December 1955 and December 1964. Erosion 
problems occur each year, especially in the form of sheet and gully 
erosion and landslides, but the magnitude is greatly increased during 
the periods of major flooding. 

Total damages resulting from the December 1964 flood were estimated at 
$63,500,000 by the Corps of Engineers for the Klamath, Trinity, and 
Smith River Basins,i/ with approximately $6,500,000 of this amount 
considered to be agricultural damage. Damages due to erosion and 
deposition were estimated by the Soil Conservation Service to be about 
20 percent of the agricultural damages, or about $1,300,000. A portion 
of the remaining damages is also associated with erosion and deposition, 
but the amount was not estimated separately from floodwater damages. 


SEDIMENT AND DEBRIS DEPOSITION 


Sediment deposits usually consist of soil and weathered rock material 
with particle sizes ranging from clay to gravel. Debris deposits con¬ 
sist of non-mineral material, both natural and man-made, such as trees, 
brush, lumber, and fencing material. 

DEPOSITION AREAS 

The major deposition areas are located in deltas near the coast and on 
the flood plains and older terraces adjacent to the main rivers and 
tributaries in the valleys. 

Agricultural 

Damages from sediment and debris deposition occur over most of the areas 
that are flooded. Crops are frequently destroyed by these deposits and 
must be replanted. Sediment consisting of sand and gravel must be 
removed, and the fields must be reshaped before planting. Logs, trees, 
and other debris must be burned or removed. Irrigation pipelines must 
be cleaned, and pumps must be either overhauled or replaced. Farm equip¬ 
ment often must be dug out of debris and sediment and overhauled before 
it can be reused. Farm buildings not swept away by the floodwaters are 


U.S. Department of the Army, Corps of Engineers, Report on Floods of 
December 1964 in Northern California Coastal Streams , San Francisco 
District, December 1965 , Vol. I., pp. 25 & 28. 


25 











often damaged and require considerable cleanup and repair. About 12,000 
acres of cropland, or 6 percent of the cropland in the basins, were 
damaged during the 1964 flood by sediment and debris deposition.!/ 

Urban 


A number of communities were damaged by sediment and debris deposition, 
and two towns, Klamath and Klamath Glen, were completely destroyed by 
floodwaters in December 1964. Others, including Happy Camp, Orleans, 
Willow Creek, and Hoopa, were severely damaged by floodwater, debris, 
and sediment, as were towns along the lower Russian River. 

Roads 


After floods, removal of sediment and debris is usually required on 
a number of roads in the valleys. Landslides are another major depo¬ 
sition problem on roads. Although they are not always a result of 
flooding, they frequently force the closure of roads. Road closures 
caused by sediment and debris deposition were extensive as a result of 
the 1964 flood, and replacement of washed out sections of roads and 
debris removal were major expenses after the flood. 

CHANHEL DEPOSITION 

At points along stream channels, aggradation decreases the channel 
capacity and increases the danger of flooding in adjacent areas. Trees, 
brush, rocks, and soil are deposited naturally into streams, but man 
adds to the problem by allowing waste materials from logging, road 
building, and agricultural and domestic activities to accumulate in or 
near channels. Debris jams sometimes form and block the channel, forc¬ 
ing the stream to overflow its banks. When these jams break up, the 
sudden rush of turbulent water accelerates the streambank erosion 
immediately downstream. Debris jams and floating debris have also 
damaged bridges, buildings, and other developments along the rivers. 

As a result of the December 1964 storm, large quantities of sediment 
accumulated in many reaches of stream channels, and streambed elevations 
increased as much as 13 feet. The U.S. Geological Survey found that 
since the 1964 flood, channel aggradation occurred at most of their 
gaging stations in the basin, but a few stations showed degradation, as 
the table on the next page shows.!-/ This aggradation problem appears 


U.S. Department of Agriculture, Soil Conservation Service, Flood Dam¬ 
age Report December 1964 - January 1965 , an unpublished report. 
(Berkeley, 1965 ). 


•John J. Hickey, Variations in Low-Water Streambed Elevations at 
Selected Stream-Gaging Stations in Northwestern California , USDI 
Geological Survey Water Supply Paper 1879 -E, (Washington, D.C., 
U.S. Government Printing Office, 1969 ). 33 pp. 


26 










Summary of Changes in Streambed Elevation 


Number 


11-4895 

-5166 

-5169 

-5175 

-5178 


-5180.5 

-5186 

-5195 

-5205 

-5215 


Gaging Station 


Namei/ 


Klamath River Basin 

Antelope Creek near Tennant 
Cottonwood Creek at Hornbrook 
Little Shasta River near Montague 
Shasta River near Yreka 
Beaver Creek near Klamath River 

East Fork Scott River at Callahan 
Moffett Creek near Fort Jones 
Scott River near Fort Jones 
Klamath River near Seiad Valley 
Indian Creek near Happy Camp 


Difference 


2 / 


in Streambed 


Elevation 
(Feet) 


0.1 

0.6 

0.2 

- 1.1 

0.4 

- 0.1 

0.1 

3.1 


-5223 South Fork Salmon River near Forks of Salmon 2.5 
-5225 Salmon River at Somesbar 

-5230 Klamath River at Somesbar 3*0 
-5232 Trinity River above Coffee Creek, near 

Trinity Center -0.3 
-5237 Coffee Creek near Trinity Center 1.4 
-5258 Weaver Creek near Douglas City -0.3 
-5259 Browns Creek near Douglas City -0.1 
-5265 North Fork Trinity River at Helena 0.8 
-5270 Trinity River near Burnt Ranch 0.6 
-5274 New River at Denny 4.0 

-5281 South Fork Trinity River at Forest Glen 2.2 
-5284 Hayfork Creek near Hayfork 0.3 
-5285 Hayfork Creek near Hyampom 0.6 
-5290 South Fork Trinity River near Salyer 12.9 
-5298 Willow Creek near Willow Creek 13.0 


11-5310 

-5325 


Smith River Basin 

Middle Fork Smith River at Gasquet 
Smith River near Crescent City 


1.5 

-0.3 


1/ 


No data is shown for gaging stations in the Russian, Clear Lake, or 
Coastal Basins. 


Difference in low-water streambed elevation between 1964 and 1965 . 
John J. Hickey, in the paper previously cited, Table I, pg. E5. 


27 











ho be temporary, and in time, degradation is expected to take place. 
Over a long period of time, the aggrading and degrading processes 
probably balance each other. 

Potential Future Problems 


The present unregulated flows have the capacity to transport sediment 
from the watershed to the ocean, but this beneficial flushing action 
could be upset if flow is regulated. A number of tributaries to the 
main rivers in the basins have high sediment yields. If a large 
reservoir were located upstream of tributaries having high sediment 
yields, the behavior of these typically fast-flowing mountain streams 
could change as follows: 

1. Coarse material may be deposited at the confluence of trib¬ 
utaries with the main stem, and regulated flows might be 
insufficient to wash it downstream. Both the main channel and 
tributary could aggrade upstream from the confluence, reducing 
the stream gradient and sediment carrying capacity. 

2. More fine material may be deposited in the reaches^where the 
sediment carrying capacity of the stream is reduced or along 
the banks where velocities are slowed by friction. Such fines 
could promote growth of phreatophytes, such as willows and cat¬ 
tails, causing further deposition and growth to encroach upon 
the channel. This buildup could change the capacity, stability, 
ecology, and beauty of the stream. 

3. In time, the deposition of this fine material on existing 
gravel beds could affect their suitability as spawning beds 
for anadromous fish. Reduction in spawning beds would in 
turn affect fishing in the problem area. 

4. Regulated flows in the main stream may not possess sufficient 
momentum to counteract tributary flows entering at an angle, 
and both streams could be deflected against the opposite bank, 
causing erosion and instability. 

This discussion of potential problems is based on examinations of exist¬ 
ing problems below Lewiston Dam in the Trinity River. Sediment problems 
in the Trinity River near Lewiston have been studhed in detail by the 
State Resources Agency.V Although the hydrologic and sedimentation 
characteristics of other rivers may differ in scale, they have suffi¬ 
cient similarity to warrant caution. 

During the planning stages of large reservoir projects, detailed studies 
should be made to predict the magnitude of potential sediment deposition 


State of California Resources Agency, Task Force Findings and 
Recommendations on Sediment Problems in the Trinity River near 

Lewiston^ (Sacramento, January 1970). 32 pp. 


28 







problems in channel reaches with regulated flows and to formulate 
remedial measures that will minimize or eliminate the problems. These 
problems may require large reservoir releases and construction of debris 
dams on heavy sediment-carrying tributaries to preserve fish, wildlife, 
and natural beauty of rivers downstream of major dams. In the attempt 
to alleviate existing problems, caution must be exercised to avoid 
creating additional problems. 

DESTRUCTION OF FISH AND WILDLIFE HABITAT 

Heavy sediment deposition in bottoms of streams and rivers destroys the 
new crops of fish eggs and the natural fish and wildlife habitat. 
Deposition of fine material in these areas generally decreases the 
numbers of fish food organisms and degrades their use as future spawn¬ 
ing areas for fish. Often, deposition fills holes In the river bed that 
are used by fish for resting areas in their journey upstream. Turbidity 
caused by high concentrations of sediment in waters can cause slower fish 
growth and, in extreme instances, death of fry and fingerlings. 

PERIODIC EFFECT ON WATER QUALITY 

During periods of high flow, usually during the months from December to 
March, considerable suspended sediment is present in many of the streams 
of the basin. Sometimes a landslide may slip into the stream and continue 
to feed sediment to the water until stable conditions are reached. Dur¬ 
ing the investigation, several streams were noted to be exceptionally 
heavy sediment producers. Muddy sediment-laden water persisted much 
longer in those streams than in others nearby. Some of the notable 
examples of heavy sediment-producing streams are listed below. 

Klamath and Trinity River Basin 
Indian Creek near Happy Camp 
Coffee Creek near Trinity Center 
South Fork Trinity River 
Pelletreau Creek near Hyampom 
Willow Creek near Willow Creek 

Smith River Basin 
South Fork Smith River 

Goose Creek (Tributary of South Fork Smith River) 

Russian River Basin 

Dry Creek near Geyserville 

Big Sulphur Creek near Cloverdale 

During the summer momths, the concentration of suspended sediment is 
very low. For example, the station "South Fork Trinity near Salyer," 
which is on one of the heaviest sediment yielding streams in the Klamath 
River Basin, has suspended load concentrations ranging from 1 to 10 ppm 
(parts per million) several days during the summer months. The maximum 
recorded concentration was 20,400 ppm on December 23, 1964. 


29 









Abnormally high suspended sediment loads affect municipal water supplies 
by adding to the cost of maintaining satisfactory drinking water. Sus¬ 
pended sediment also causes problems with mechanical equipment such as 
pump bearings, impellers, and filter beds. For example, such problems 
are causing considerable expense to the Humboldt Bay Municipal Utility 
District, which gets its water from the N&d River upstream of Areata 
(in the Mad River Basin). 

RESERVOIR SEDIMENTATION 

Reservoir sedimentation causes a loss in storage capacity. Surveys were 
made on four reservoirs in the Russian Basin, and the results of these 
surveys are shown in the section "Special Sediment Studies" of the 
Addendum. The surveys showed that annual loss of original storage 
capacity ranged from 0.24 to 2.3 percent. Surveys have not been made 
on the existing larger reservoirs east of Interstate Highway 5 in the 
Klamath Basin because these have no history of high sedimentation. 

Although no official surveys have been made, sediment deposition in 
Clair Engle Lake has been estimated. Suspended load data collected at 
the gage "Trinity River near Lewiston" prior to dam construction 
indicate a mean suspended sediment load of about 300 tons/square mile/ 
yearTen percent was added for bedload, making the total load an 
estimated 330 tons/square mile/year. The drainage area above Trinity 
Reservoir is 688 square miles; therefore, the annual inflow of sediment 
is estimated to be about 227,000 tons per year. Assuming a density of 
70 pounds per cubic foot (l ,525 tons/acre-foot), about 150 acre-feet per 
year is being deposited in the lake. The original storage capacity was 
2.5 million acre-feet, so the storage depletion is only about 0.006 
percent per year. 

Estimates of long term sediment yield for all suspended sediment gaging 
stations are presented in the section "Special Sediment Studies" at the 
end of this appendix. Sediment yields vary considerably from basin to 
basin and are a major factor to be considered in planning and designing 
reservoirs. 


SOIL EROSION 


Soil erosion problems were grouped into three main sources for study -- 
streambank, landslides, and sheet and gully erosion. 

STREAMBANK EROSION 

Terraces and alluvial fills are the major land forms subject to stream- 
bank erosion. These generally have steep banks which will slough when 


i4 


ee table "Mean Annual Sediment Discharge" 


in the Addendum. 


30 




Landslide damage to a seventy-foot high road fill. 

s c s 


PHOTO 3-5735-6 




Sediment deposition in a typical farm pond, scs photo 3 - 1234.9 


31 





undercut by streams. Terraces were formed by historic deposition and 
are usually located in wide canyon bottoms or valley floors. Alluvial 
fills are generally deposited along the inside of curves in streams or 
at the confluence of tributaries. Measured sediment rates per mile of 
channel are generally high in these terraced or alluvial areas, while 
the rates in narrow canyons with steep slopes and shallow soils are 
generally lower. Sloughing occurs as the toe of streambank or adjacent 
slope is undercut by streamflows. 

Most streambank erosion appears to be a natural occurrence, but sometimes 
it is the result of man's activity upstream. Debris dams formed by 
such activity may suddenly collapse and release large quantities of water 
during a storm, causing a sudden acceleration of streambank erosion 
immediately downstream. Much of this type of streambank erosion occurred 
in the Klamath River during the December 1964 storm and had a heavy 
impact on roads and recreation sites. 

LANDSLIDES 

In much of the study area, topography is extremely rugged, rocks are 
relatively young and unstable, and annual rainfall is high and con¬ 
centrated in the winter months. During the periods of high■rainfall 
the rock formations which are often poorly consolidated, highly fractured, 
and structurally weak become saturated, as do the soils, and as a result 
landslides commonly occur. 

Landslides are often triggered by stream action which removes the slope 
toe, especially in steep, narrow canyons. Man's activities, such as 
logging, vegetal cover conversion, and road construction, increase land¬ 
slide incidence by decreasing slope stability in already unstable areas. 

Once a slide has occurred, much of the surface area is left bare, and 
the surface soil material is generally loosened, increasing the hazard 
of sheet and gully erosion. The slide area usually remains unstable and 
is subject to future sliding, especially if the toe is again removed. 

SHEET AND GULLY EROSION 

Sheet and gully erosion is more often directly related to man's activity 
on the land than are streambank erosion and landslides. Historically 
those activities have included farming, livestock grazing, logging, road 
building, and most recently, recreation. Each of these activities has 
modified the land surface. 

Logging 

Logging affects soil erosion by temporarily removing vegetal cover and 
by disturbing soil during skidding and yarding operations and construction 
of logging roads. Even when using the most modern conservation techniques, 
some erosion is inevitable. Poor logging practices have caused serious 
soil disturbances in the form of excessive numbers of skid trails, 
stream crossings and landings; improperly located skid trails, landings, 
and spur roads; water pollution from debris entering stream channels; 
and the erosion of temporary road fills caused by inadequate culverts. 


32 



These practices are aggravated by inadequate post-harvest erosion 
control treatment. For example, skid trails and landings are too often 
not drained, spur roads not closed or drained, and temporary fills 
across intermittent stream channels not removed. 

In the past fifteen years, logging practices have improved in national 
forests. Areas logged prior to 1955 often showed the shortcomings cited 
in the previous paragraph, and by the late fifties, the need for erosion 
control procedures became apparent. Areas were formerly logged using 
crawler type tractors, a method which caused excessive soil disturbance 
on steep slopes. Presently, tractor logging in national forests is 
limited to slopes of less than 35 percent, and steeper areas are logged 
by overhead cable systems, such as high lead or skyline. These logging 
methods cause less disturbance to land and reduce the resulting erosion. 
The three yarding systems now in use are discussed more thoroughly in 
the chapter "Land Treatment Programs." Most problems were associated 
with access roads and skid trails rather than the logging itself. 

On very deep soils in the Mendocino Coastal vicinity, large private 
concerns still log slopes that have gradients of up to 60 percent by 
conventional skid-tractor logging methods. Though large volumes of 
soils are disturbed on the contour, little observable sedimentation 
results, and vegetal regrowth is rapid. Further inland, on deep soils, 
the same logging practices result in much soil loss. The apparent 
reason for this difference is that the very deep soils have the ability 
to infiltrate, percolate, and store large volumes of rain. 

The present sediment rates from national forest areas logged ten or 
more years ago still reflect the poor practices used at that time. They 
still show the scars of logging, many of which are healing slowly, if 
at all. The sedimentation rates from these areas are higher than would 
be expected if they had been logged under the present standards. 

Grazing 


For more than a century, privately owned natural grassland and adjoining 
forest land converted to grass have been subjected to heavy grazing .U 
On much of the land, the more desirable grass species have been elim¬ 
inated, and the poor quality of the replacement forage will no longer 
allow ranges to support the number of livestock for the length of season 
once possible. Perennial rangeland vegetation has generally been replaced 
by less adequate annual cover. 

There is a general contrast between the soil erosion on grasslands in the 
Northern Basins and that in the Southern Basins. In the Northern Basins, 


L.T. Burcham, California Range Land, An Historico-Ecological Study 
of the Range Resource of California, pp. 199-205 (Sacramento; 
California Department of Natural Resources, Division of Forestry, 
1957). 


33 












Loamy range site. Both sides of fence are in poor condition 3 with 
eheatgrass and sagebrush cover. On right side of fence the range 
is severely over-utilized. scs photo 3 - 5 * 63-4 


the soil erosion problem is relatively small. In the Southern Basins, 
however, approximately one-third of the grassland has insufficient 
vegetal cover to protect the soil from sheet and gully erosion, and 
soil creep and slumps are prevalent. The situation is especially 
critical on private rangelands that are grazed throughout the year. 
Analyses of field data indicate that the percentage of bare ground is 
probably the most important factor related to sediment yield on grass¬ 
lands . 

In the Southern Basins, grasslands converted from timberlands have higher 
sediment yields per square mile than those from natural grasslands, 
especially on slopes steeper than 20 percent. Timber soils, being more 
acidic, tend to produce woody vegetation and poor quality grass cover 
causing the converted land to have more exposed ground. The number of 
gullies and small, shallow landslides per unit area is greater in con¬ 
verted areas than that on natural grasslands. This has been only a 
minor problem in the Northern Basins because very little timberland has 
been converted to grassland. 

Prior to the establishment of national forests in the North Coastal Area, 
most of the rangeland in these areas was heavily grazed and some was 
destructively grazed. In some cases, this overgrazing continued into the 
early years of the national forests, and sheet and gully erosion increased 
as a result of the deterioration of the vegetal cover. Most national 


34 




forest grazing land has now been placed in range allotments or closed 
to grazing because of high erosion hazard. 

Deer 


Although many wildlife species exist in the North Coastal Basins, only 
deer appreciably influence erosion or sediment yield. When deer 
populations are concentrated, their heavily travelled paths and browse 
areas expose bare soil to erosion, especially during the rainy season. 

As deer feed in brush or grassy openings, they tend to work around 
preferred browse plants, creating more trails and retarding vegetal 
growth. 

Deer-caused erosion is considered a problem only in the Southern Basins. 
In most parts of the Northern Basins, only a small amount of such erosion 
was found. 

Land use practices, such as type conversion or logging, modify vegetal 
cover over large areas, at least temporarily. The normal plant suc¬ 
cession is first grasses, then shrubs, and finally trees. The new 
shoots of the shorter grasses and shrubs are favored deer feed, and 
stabilization of a disturbed area is often delayed because the herd 
continually browses the short, tender plants. The crown canopy of 
large shrubs and young trees, which succeed the grasses and small 
shrubs, must grow beyond the reach of browsing animals before the area 
will stabilize. Also, reforestation efforts are hampered by deer-browsing 
of seedling trees, often resulting in substantial financial loss to 
timberland owners. Until vegetal cover is established, soil is exposed 
to the weather and subject to sheet erosion and gullying. In the 
Southern Basins, field observations of widespread over-browsing of 
forage or severe trampling indicate that present deer populations exceed 
the carrying capacity of their range.- 

Burning 

The climate of the basins in the study area is characterized by warm, 
dry summers where rain is minimal from June through October. This 
climate and the vast expanses of woody vegetal cover combine to create 
a high potential fire hazard. The severe erosion that often follows 
wildfire, particularly on steep slopes, is usually attributed to salvage 
logging. 

Despite the high potential, wildfire has been insignificant as a cause of 
erosion in these basins because the average annual acreage'burned by 
wildfire has been small. This record is attributable to the cooperative 
efforts of the. fire protection agencies at all levels and a cooperative 
public that is becoming more aware of the problems coincident to burning. 

Controlled burning, although used less in recent years, is still a land 
management tool in these basins. It has been used extensively in the 
Southern Basins to convert timber or brush covered lands to grass cover 
and to maintain the conversion. It is also an effective way to dispose 
of slash and debris from newly logged areas, for fire reduction, pest 


35 









habitat elimination, and preparation of planting sites for reforestation 
of Doug]as-f .i r or redwood. However, the ever-increasing demand for 
control of air pollution and concern for scenic beauty will probably 
preclude use of burning in the future. 


Recreation 


Although the overall sediment yield from recreation is not a problem 
at the present time, some recreation areas presently have high sediment 
rates and a serious problem could develop yn the future. Recreation use 
is expected to expand significantly as more recreation sites are develop¬ 
ed and new and improved highways make these facilities more accessible. 
Haul roads constructed for logging operations in national forests are 
opening up new areas that were previously considered inaccessible to 
most types of recreation. This is probably true of private timberlands 
also. Sheet and gully erosion will increase unless careful planning 
and good construction methods are used in the development of recreation 
facilities. 

Croplands 


Sheet and gully erosion is not a problem on most croplands 'because they 
are used for non-irrigated pasture or generally lie on gentle slopes. 
Erosion has been moderate or severe on some sloping cropland, such as 
vineyards. In time, additional grassland will probably be converted to 
cropland, and erosion potential will increase with the conversion. 

Roads 


In the North Coastal Basins, the road system acts as the arteries of 
the local economy. Because of the isolated nature of the towns and 
industries, disruption of any part of this system can immobilize com¬ 
munities in the affected area. Such occurrences were widespread as a 
result of the December 1964 storm. Tourism and recreation in the Redwood 
Region are sometimes hampered because of poor road conditions or delays 
during summer maintenance periods. 

Road related erosion problems usually stem from poor location, design, 
construction, and maintenance. These often cause landslides, aggravate 
streambank erosion, disrupt drainage patterns, mar the beauty, and require 
costly maintenance or even costlier reconstruction. 

Many examples of faulty road location were noted in all of the basins. 
Construction on lower slopes of steep-sided, narrow canyons, encroachment 
of roads upon streams, and alignment through obviously unstable areas were 
the major problems found. Roads located on the lower portions of slopes 
intercept more surface and ground water, thereby increasing surface 
erosion and landslide activity. Those encoraching upon streams constrict 
the channel, either resulting in undercutting of the road or forcing water 
against the opposite streambank and accelerating bank erosion. Roads in 
unstable areas pose a constant problem in that landslides and slips are 
common and maintenance costs are high. Misalignment of bridges and 
culverts in relation to stream channels causes turbulence and deflection 
of flows against erodible banks. 


36 





Major road design problems found in the basins are the steep, bare cuts 
and fills, many of which have long, uninterrupted slopes, and the in¬ 
adequate drainage systems. The largest volumes of road-caused erosion 
and sediment yield comes from cuts and fills. Erosion on unsurfaced 
roadways is a minor problem. Erosion problems from construction occur 
mostly on minor roads, such as logging spurs, farm and ranch access 
roads, and some residential roads, where little or no design was made. 
These problems include inadequate erosion protection for borrow pits and 
waste fills; sidecast trees, rocks, and excess soil, and improper stream 
crossings. 

Inadequate surface drainage design is compounded by the severance of 
continuous substrata layers, which disrupts the normal lateral water 
flows. When severed, these flow planes create supersaturated masses 
of soil materials in cut banks, which build up weight, lubricate weaken¬ 
ed surfaces beyond shear limits, and slump. Other problems associated 
with the exposed road cross-sections are rain splash and rillwash of 
raw cut and fill slopes, downcutting along gutters and flushing of the 
dry-fall debris from these gutters, puddling along the road surfaces, 
uncontrolled spillway breaches, cutting action of runoff down rut tracks, 
erosion of fill materials by and around hanging culvert outlets, lack 
of energy dissipators at downspout ends, and runoff impact on channel 
banks from intercepted flows from adjacent hillsides. 

Poor maintenance practices are another major cause of soil erosion and 
sediment yield from roads. The toe of cutbanks is removed by maintenance 
equipment, causing sloughing and sliding, and excess roadside surface 
material sometimes leaves a berm at the outside edge, permitting runoff 
to concentrate and cause erosion. Sometimes when road ditches are 
cleared the waste is dumped over the road bank, often directly into a 
stream. Using unsurfaced roads during the rainy season causes ruts 
that channel water and erode the surface. Sometimes plugged culverts 
are not cleaned out prior to the rainy season, and gullies are formed 
by the diverted flows. Too often, unsurfaced roads are not graded or 
maintained during the early spring months, when proper soil moisture is 
available to obtain the best results. Temporary roads are often used 
indefinitely even though they were originally designed for short term 
use. They usually receive little maintenance, resulting in additional 
erosion. 


LIMITATION OF POTENTIAL LAND USE 


SOUTHERN BASINS 

Erosion reduces the maximum potential use of lands in the basins. 
Streambank, sheet, and gully erosion, along with floodwaters, prevent 
much of the cropland from being intensively farmed. As topsoil is 
removed by landslide, streambank, sheet, and gully erosion, the livestock 
carrying capacity of grassland is reduced, and in time, this erosion 
destroys its agricultural potential. Similar problems on timberland 
limit its potential for maximum production, and erosion of tirnberland 


37 






converted to grassland may reduce its potential for reforestation. 
About 4b square miles of grassland and one square mile of converted 
timberland are in the severe erosion class and have lost most of their 
potential as productive lands. The best use of these lands is for 
watershed and wildlife areas. 

NORTHERN BASINS 

No survey of eroded land was made in the Northern Basins since severe 
erosion did not appear to be extensive. 


ENDANGERED DEVELOPMENTS 


Erosion of streambanks and gullies can cause the destruction of homes 
and buildings and endanger lives; damage or destruction of utilities 
could result in explosion, electrocution, or fire; interruption of 
water service may occur, which may increase disease hazard; and destruc¬ 
tion of existing flood control facilities may occur. 


INCREASED COSTS FOR IAND OPERATIONS 


Erosion, particularly that connected with gullies and landslides, reduces 
the efficiency of land operations and increases operating costs. It 
causes delays, forcing operators to spend time and money on non-pro¬ 
ductive work. Gullies and landslides can interrupt livestock travel 
patterns, leading to uneven forage utilization and overgrazing of some 
areas. Logging may be hampered by blocked skid trails and spur roads, 
and the necessity of working around problem areas may force expensive 
changes in plans. 


INCREASED RUNOFF RATES 


Sheet and gully erosion causes an increase in runoff by removing topsoil 
and reducing the soil's capacity to grow good vegetal cover. 


DESTRUCTION OF FISH AND WILDLIFE HABITAT 


Several reaches of eroded channel bottoms were found^which indicates 
losses of fish habitat. Fish spawn in gravelly stream bottoms and feed 
on nearby aquatic life. Erosion of the gravel can destroy egg crops and 
reduce the food supply. 

Many areas were found, especially in the Southern Basins, where erosion 
has reduced the capacity of the land to produce forage and cover for 
deer and other wildlife. This forces the animals to concentrate in 


38 






other areas, causing additional overbrowsing problems. A related 
problem is caused when wildlife, particularly deer, find their normal 
ranges decimated and encroach upon croplands and areas where timber 
growers are attempting to reforest. The general health of deer herds 
is affected by lack of good habitat. 


DESTRUCTION OF RECREATION POTENTIAL AND SCENIC BEAUTY 


In many areas throughout the basins, scars from erosion detract from 
the natural beauty, lower land values, and reduce the recreation 
potential. This erosion has little effect on the total use of the 
area for recreation, home building, or tourism, but has a marked effect 
in those localities where it is excessive. 


ADVERSE IMPACT ON LOCAL ECONOMY 


When erosion reduces the productivity of the land, the economy of the 
North Coastal Area is adversely affected. Loss of production from 
timber, grazing, recreation, farming, fishing, and hunting directly 
affect the income of landowners. This, in turn, starts a chain reaction 
that has impacts upon all supporting businesses and upon employment in 
the area. 



Landslide in road out on State highway 299 along the Trinity River. 

SCS PHOTO 3-5735-12 


39 








SEDIMENT YIELD STUDIES 




Pediment deposits in small reservoir, 
'iocn River Basin. 


Tributary to Dry Creek 3 Rus- 


Flood-bome sediment on a young orchard in Anderson Valley 3 
Mendooino County 3 1965. s CS »»oto 




4o 







In this chapter, sediment yield studies are described, present sediment 
data are shown, and predictions of future yields are presented. Future 
sediment yields that can be expected by the year 2020 were predicted 
assuming that a land treatment program is not installed. The total 
sediment yield was divided into three principal sources -- sheet and 
gully, streambank, and landslide erosion -- and each was studied 
separately. Sediment yield from roads is included under sheet and 
gully erosion, whereas in the Eel and Mad River Basins study reported 
in Appendix Wo. 1, roads were considered a separate source. The 
Northern Basins -- the Klamath, Trinity, and Smith -- and the Southern 
Basins -- the Russian, Mendocino Coastal, and Clear Lake -- were grouped 
and are discussed separately because of substantial differences in 
location, sediment yield characteristics, problems, and solutions. 

A more detailed survey entitled Reconnaissance Survey Report--Conserva ¬ 
tion Treatment of the Dry Creek Watershed , dated February 1966,is 
available for the Northern Russian River Basin. 

The table on the next page, "Present Annual Sediment Yields by Source," 
presents the total sediment yields from each basin by source. Stream- 
banks yield 47 percent of the total; sheet and gully erosion yield 28 
percent; and landslides yield 25 percent. 

The Northern Basins presently yield an estimated 5,9^0 acre-feet of 
sediment annually from 10,795 square miles of watershed, an average of 
about 0.55 acre-feet of sediment per square mile per year. 

The Southern Basins presently yield an estimated 4,950 acre-feet of 
sediment annually from 4,04l square miles of watershed, an average of 
about 1.22 acre-feet of sediment per square mile per year. 

Caution should be used when interpreting the sediment yield rates 
presented in this chapter. These values imply greater accuracy than 
is warranted by the survey procedures used; however, they are useful 
in comparing the differences between sources and causes of sediment 
yield in the various basins and in evaluating the effects of land use 
practices and remedial programs. Also the sediment rates presented in 
this chapter are the estimated averages and, in any given year, may be 
several times more or less than these average rates. 

It is estimated that total sediment yields in all basins will increase 
by l6 percent or 1,720 acre-feet per year if an effective land treatment 
program is not installed. These future yields are shown in the table 
"Future Annual Sediment Yields by Source." Reductions in yields that 
can be achieved with a program are discussed in the chapter "Recom¬ 
mended Land Treatment Program." 

The maps "Annual Sediment Yield--Northern Basins" and "Annual Sediment 
Yield--Southern Basins" are presented on the following pages. Estimates 
of the rates in Oregon were prepared by the SCS State Office Staff in 
Oregon. 


4l 




Present Annual Sediment Yields by Source 


Sediment Sources in Acre-Feet Per Year 


Basin and 

Subbasin 

Area 

(Sq.Miles) 

Stream- 

banks 

Land 

slides 

Sheet & 
Gully 

Total 

Northern Basins 

Klamath River 

Butte Valley- 

Lost River 

2,309 

10 

T 

50 

60 

Salmon-Scott- 

Shasta 

2,199 

440 

180 

100 

720 

Middle Klamath 

1,756 

430 

580 

180 

1,190 

Mouth of Klamath 

772 

450 

160 

160 

770 

Subtotal 

7l03£ 

1,330 

920 

490 

2,740 

Trinity River 

Upper Trinity 

1,013 

350 

60 

370 

780 

Lower Trinity 

1,024 

510 

100 

no 

720 

South Fork Trinity 

932 

380 

570 

190 

1,140 

Subtotal 

2^9 

1,240 

730 

870 

2^840 

Smith River 

790 

290 

200 

70 

560 

Total 

10,795 

2,880 

1,850 

1,230 

5794 o 

Southern Basins 

Russian River 

Northern Russian 

1,010 

630 

160 

4io 

1,200 

Southern Russian 

475 

270 

20 

170 

460 

Subtotal 

5 

900 

ISO 

580 

1,660 

Mendocino Coastal 

Mattole River 

499 

550 

4oo 

380 

1,330 

Central Mendocino 

666 

190 

120 

270 

580 

Southern Mendocino 

933 

470 

230 

4oo 

1,100 

Subtotal 

2,098 

1,210 

750 

1,050 

3,010 

Clear Lake 

458 

110 

10 

160 

280 

Total 

4,o4l 

2,220 

94o 

1,790 

47950 

Grand Total 

14,836 

5,080 

2,790 

3,020 

10,890 


42 









































Future Annual Sediment Yields by Source Without Program 


Sediment Sources in Acre-Feet Per Year 


Basin and 

Subbasin 

Area 

(Sq.Miles) 

Stream- 

banks 

Land 

slides 

Sheet & 
Gully 

Total 

Northern Basins 

Klamath River 

Butte Valley- 

Lost River 

2,309 

10 

T 

60 

70 

Salmon-Scott- 

Shasta 

2,199 

440 

230 

120 

790 

Middle Klamath 

1,756 

430 

730 

190 

1,350 

Mouth of Klamath 

772 

450 

200 

160 

810 

Subtotal 

7,036 

1,330 

1,1^0 

530 

3,020 

Trinity River 

Upper Trinity 

1,013 

350 

80 

390 

820 

Lower Trinity 

1,024 

510 

130 

120 

760 

South Fork Trinity 

932 

380 

710 

210 

1,300 

Subtotal 

2,969 

1,240 

920 

720 

2,880 

Smith River 

790 

290 

250 

80 

620 

Total 

10,795 

2,860 

2,330 

1,330 

6,520 

Southern Basins 

Russian River 

Northern Russian 

1,010 

630 

200 

430 

1,260 

Southern Russian 

475 

270 

30 

170 

470 

Subtotal 

i7W 

900 

230 

600 

1,730 

Mendocino Coastal 

Mattole River 

499 

550 

500 

710 

1,760 

Central Mendocino 

666 

190 

150 

370 

710 

Southern Mendocino 

933 

470 

290 

850 

1,610 

Subtotal 

2,098 

1,210 

9 ^o 

1,930 

4 ^So 

Clear Lake 

458 

110 

10 

160 

280 

Total 

4,041 

2,220 

1,180 

2,690 

6,090 

Grand Total 

14,836 

5,080 

3,510 

4,020 

12,610 


4,3 










































LEGEND 



ANNUAL SEDIMENT YIELD IN 
ACRE FEET / SQUARE MILE 

I I >2 ° 

I I 10 - 2.0 

HI 0.5— 1.0 


ANNUAL SEDIMENT YIELD 

SOUTHERN RIVER BASINS 

HUMBOLDT, LAKE, MENDOCINO, AND SONOMA COUNTIES, 
CALIFORNIA 

NOVEMBER 1971 


RIVER. 


SCALE 1760,320 


is MILES 






























LJ 1.0—2,0 

□ °- 5 -' 0 


This mop is intended for general plonning. 
detailed maps for. operational planning, and or 
inspection for more detoiled decisions. 


ANNUAL SEDIMENT YIELD 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 

NOVEMBER 1971 

MILES 

SCALE 1:1,250,000 


LEGEND 

River Basin Boundary 
— - Sub-Basin Boundary 

BASINS 

A a F KLAMATH RIVER 
F - H TRINITY RIVER 
8 SMITH RIVER 

SUB-BASINS 

A UPPER KLAMATH LAKE 
® BUTTE VALLEY-LOST RIVER 
Q MIDDLE KLAMATH RIVER 
D SALMON RIVER AND SCOTT 
AN0 SHASTA VALLEYS 
E MOUTH OF THE KLAMATH RIVER 
F UPPER TRINITY RIVER 
G SOUTH FORK TRINITY RIVER 
(H) LOWER TRINITY RIVER 


































SHEET MD GULLY EROSION 


Sheet and gully erosion presently contributes about 3 5 020 acre-feet per 
year, or nearly 28 percent of the total sediment yield of the basins. 

This yield is attributed to six principal causes -- logging, grazing, 
roads, cultivation, deer browsing, and natural causes. 

If the land treatment program recommended in this appendix is not 
installed, future sediment yields from sheet and gully erosion are ex¬ 
pected to increase 33' percent to 4,020 acre-feet per year. 

SURVEY PROCEDURES 

A basic category map was developed which showed specific combinations 
of mappable factors that were thought to affect soil erosion and sedi¬ 
ment yield. The four major factors selected were soil-slope association, 
vegetal cover type, land use, and land ownership. These are further 
described in the chapter "Land Resources and Use." The map was based 
on the most recent U.S. Geologic Survey Topographic Quandrangles 
(15-minute) and on aerial photographs taken in 1965 * 

The map was used only as a working tool, and is not presented in this 
appendix. It showed the areas and distribution of each basic category 
and was used to apportion the number of field plots to the categories 
and to expand the sample data over the basins. 

Seventy-eight soil-slope associations formed the basis for the category 
map, and the vegetal cover types delineated were conifer, woodland, 
conifer-woodland, woodland-grass, grass, brush, cropland, and barren. 

Land uses isolated were undisturbed, logged,logged and burned, type 
converted, type converted and burned, burned by wildfire, and culti¬ 
vated. Grazing was considered as a land use but was not delineated on 
the category map because no source maps showing the area grazed were 
available. This area was determined by soil and vegetation acreage 
measurements from the category map. Two ownership classes, national 
forest and other, were also delineated. These factors were combined 
into the basic category map by the use of the MIADS2-L/ computer program. 

Categories representing over one percent of the watershed area were 
selected for sampling; those comprising less than that were combined 
with similar categories unless they had a special significance. The 
number of plots located within a basic category varied according to its 


Elliot L. Amidon, MIADS2, An Alphanumeric Map Information Assembly and 
Display System for a Large Computer , U.S. Forest Service Research 
Paper PSW- 38 , (Berkeley, Pacific Southwest Forest and Range Experiment 
Station, 1966 ). 12 pp. 


44 













This Douglas Fir site cleared by girdling in 1918 is shown ten years 
later. Note serious gully erosion brought about by the land use 
conversion plus heavy grazing use. y SFS photo 



Same site in 1953. Note increase in both size and extent of gullying 3 
a result of continuing heavy grazing. 

45 


SCS PHOTO 3-1559-9 




size, homogeneity, and distribution. Sample plots were selected using 
aerial photographs; accessibility of a site was an important consid¬ 
eration in the selections. 

Depth of erosion, period of occurrence, percentage of the eroded material 
that reached a stream, and the causes of erosion by percentage were 
estimated in the field for each plot. Other data, such as ground cover 
density, percent bare ground, and condition of the vegetal cover, and 
management recommendations were also recorded. 

In the investigation of sediment yields caused by roads, those outside 
the national forests were classified in categories using the USGS 
Topographic Quadrangles, while those inside were classified using 
Forest Service Development Transportation Plan Maps, which showed more 
road detail. Only the roads shown on these maps were considered in 
this study, and sediment yield from other roads, such as logging spurs, 
was estimated as a part of the plots described in the previous para¬ 
graphs. A proportionate number of samples was taken in each of the 
road categories. 

Two different sampling techniques were used during the course of the 
study, but results were similar. Some roads in the national forests 
were sampled with a plot system using 100- to 500 -foot lengths of road. 
Measurements of grade and roadway and cut-fill widths were taken, and 
estimates of the amount of erosion and the percent delivered to the 
streams were made. On other roads, plot lengths were longer, up to 
several miles, and the measurements were estimated while driving slowly 
along the roads. 

DATA ANALYSIS 

Although there were slight variations in procedures, the same general 
analyses were used to determine the sediment yields in all basins. 

Using sample data from field plots, erosion rates were determined for 
each of the basic categories, and these rates were applied to the area 
of that category. In each basin, the total erosion volume was deter¬ 
mined by summing the eroded volumes of each category. The average 
percent of eroded material reaching the streams was determined and was 
applied to the total erosion volume to arrive at the sediment yield for 
each basin. The percent of sediment yield assigned to each cause was 
determined by averaging the estimated percentages recorded in field 
samples for each basin. 

Analysis of road-caused sediment yield followed the same general 
procedure except that road lengths rather than gross areas were used 
as the basis for calculations. From the sample data collected for 
each of the road classifications, the aggregate total of annual sedi¬ 
ment rates and the lengths of sample reaches were determined. The 
weighted average annual sediment rate in acre-feet per year per mile 
of road was computed and was multiplied by the total length of roads 
in each basin to arrive at the annual sediment yield for each road 
classification and basin. 


46 





PRESENT SEDIMENT HELD 


The results of the sediment yield studies for the Northern and Southern 
Basins are discussed separately because the physiography and climate of 
the two areas are quite different. 

Southern Basins 


For the 4,041-square mile area of the Southern Basins, the average 
sediment rate from sheet and gully erosion is about 0.44 acre-feet per 
square mile per year, which accounts for approximately 36 percent of 
the total sediment yield from all sources. The Mendocino Coastal Basin 
has the highest sediment rates from sheet and gully erosion, with about 
0.50 acre-feet per square mile per year, followed by the Russian River 
Basin, with about 0.39 acre-feet per square mile per year, and the Clear 
Lake Basin, with about 0.35 acre-feet per square mile per year. The 
percentage of sediment yield from sheet and gully erosion for each 
cause is as follows: logging - 28 percent, grazing - 26 percent, 
deer - l8 percent, natural erosion - l8 percent, roads - 7 percent, 
and cultivation - 3 percent. 

The following table "Present Sediment Yields from Sheet and Gully 
Erosion in the Southern Basins" shows the annual sediment yields for 
each basin by cause. The accompanying table "Present Sediment Rates 
from Sheet and Gully Erosion in the Southern Basins" shows the annual 
rates per square mile for each cause. 

The sediment rates from sheet and gully erosion are about the same for 
the three basins, but because of size and the large portion logged with 
tractors, the Mendocino Coastal Basin yields substantially more sediment 
than the other two. When considering sediment from sheet and rill 
erosion alone, the Clear Lake Basin has a considerably higher sediment 
rate. In this basin many hillsides with highly erodible soils are 
covered with chaparral. A considerable acreage of these soils is denuded 
each year. This causes a high sediment rate from sheet and rill erosion, 
although stream density in the basin is lower than that in the other two. 
The sediment rate for sheet erosion alone in the Russian Basin is higher 
than that in the Mendocino Coastal Basin probably because stream density 
is slightly higher. 

Gully erosion accounts for most of the sediment yield in the Mendocino 
Coastal Basin. These gullies are usually associated with skid trails and 
rutted roads. A high proportion of sediment from gullies is delivered 
to streams, and stream density apparently has little effect on sediment 
yield. 

Logging causes 28 percent of the sediment yield from sheet and gully 
erosion, about 500 acre-feet per year. Over 90 percent of the logging- 
caused sediment yield occurs in the Mendocino Coastal Basin, and a large 
proportion is attributed to gullying caused by poor logging and post- 
logging practices. Most of the timber land in this basin is privately 
owned, and logging is generally done by tractors, even on steep slopes. 
The Mattole River Subbasin has the most acreage logged and yields the 
most sediment. 




47 




1 —1 

O 

0 

0 

O 



aj 

00 

LTV 

VO 

00 



p 

UA 

O 

1—1 

IP 



0 




C\ 


ctf 

EH 


1 - 1 


1—1 


(D 













(D 

(L> 






-P 

1 —1 

1 — 1 





aj 

•rH 

aj 





K 

S 

P 

O 

O 

0 

0 


* 

2 

CVI 

00 

CO 

00 

P 

a 1 

P> 

1—1 

1—1 


00 

£ 

GO 

aj 





0 


S 





£ 

p 






•1 —1 

0 






■rS 

0 ) 






0 ) 

Ph 






co 

1 

P 

0 

O 

0 

0 


a) 

0 


1—1 

-d- 

CVI 


P 

0 

1—1 

1—1 


00 


0 

O 






< 


a 


■ 


i>= 




O 







r—- 

rH 




•H 





!>> 

ts 

m 

1 —1 


P 


p 





r—1 

0 

0 

£ 


aj 


aj 



0 


1 —1 

p 

1 — 1 

0? 


CD 


> 

0 

0 

0 

O 

£ 

0 

•rH 



>H 


•rH 

-d 

CVI 

aj 

VO 

c£ 

0 

s 

Ti 




P 



P 



P 


£ 

M 

P 

£ 

1 —* 



Eh 


m 

P 

0 

aj 

£ 

0 

aj 

£ 





£ £ 

< 

p 


•rH 

Ph 

S 

O 





aj *rH 


aj 

P 

w 








w 

03 

£ 

0) 

aj 

P 

>> 






P aj 

0 

cr* 

0) 

m 

0 

PP 






0 PP 

p 

CO 

r£ 


0 







0 

c 

- - r 

CO 

£ 

Ph 

n£ 

w 





P £ 




P 

1 

0 

TJ 





CO P 



£ 

CD 

0 

O 

aj 

O 

O 

O 

O 

0 



0 

,£ 

P 

£ 

O 

LTV 

VO 

1 —1 

CVI 

£ r£ 



P 

P 

O 

0 

ffi 




1 —l 

0 p 


I—1 


£ 

<c 

£ 






P £ 

p 

aj 


O 


1 —1 






Ph O 

£ 

P 

w 

CO 


P 






CO 

0 

O 

t£ 



£ 






w 

O 

EH 

1 —l 

CD 


H 

faD 





0 0 

P 


0 

,£ 



£ 





P P 

0 

P 

•rH 

P 



•rH 

O 

O 

O 

O 

aj P 

Ph 

O 

>H 



r-H 

IS] 

30 

LTV 

m 

VO 

Ph 




£ 


P 

aj 

1 —1 

CVI 


_d 

£ 



P 

•iH 


O 

P 





p -H 






0 

O 





£ 



0 

£ 


P 






0 £ 


r ' 

£ 

O 


•rH 






£ 0 

Ti 

P 

•rH 

■rH 


P 






•H -H 

1 —1 

aj 


W 








H£ CO 

0 

0 

0) 

O 



fad 





0 O 

•rH 

>H 

CO 

P 



£ 



0 


CO P 

>H 



p£) 



•rH 

O 

0 

0 

O 

PP 


P 

p 




fad 

CVI 

CO 

aj 

O 

P 

P 

0 

£ 




bd 


-d" 

p 

LTV 

£ 

£ 

0 

CD 




0 



Eh 


0 

0 

Ph 

w 




p 





w 

£ 

1 

a) 









0 

•rH 

0 

P 









P 


P 

Ph 










CD 

O 











m 






ra 












0 












1 — 1 

l r\ 

CO 

00 

1 —1 







aj 

•rH 

30 

ov 

LTV 

-d" 







0 


-d" 

0 

-£■ 

O 







P 

• 

•\ 

#\ 









< 

CJ* 

1—1 

CVI 


-d" 





CO 


i—I 
aj 




p 






w 



H 



aj 



1 —l 


0) 

O 



0 


i> 

O 


1 —1 

• rH 


• r-\ 


0 

a3 

>H 


PP 

O 

PP 

P 




£ 

aj 

O 

P -P 


£ 

• iH 

i-P 

EH 

O £ 


ctf 

0 




£ 

•1 —1 

0 

P 


0 £ 

•rH 

w 

tJ 

a? 


W H 

CQ 

m 

£ 

0 


£ H 

a3 

2 

0 

1 -1 


aj 0 

PQ 

Ph 

2 

O 


0 CO 


P 

>h 



P 


i 

o 

< 


co 

O 

o* 


0\-=f 

1 —1 

rH CO 

VO 1 —1 CO 

1 — 1 

1 —1 0 

• • • 

• 

• • 

O O 

0 

0 0 


CTV CM 

UA_d- 

CM H 

CM VO 

CM OO 

t— Pf 

0- CM 

LTV 

ON O 

«A 


CN *- 

CO 


CM J- 


co vd c— on oo co 
cm cm i—i h 


o o o o o o 

O VO CM VO CVI CO 

LTV J- I—I CO CO 


£ 


aj 








2 








2 








PQ 








TJ 








0 








a 








£ 




£ 




0 




O 




£ 




•rH 




1— 1 




P 




P 

faD 

faD 


aj 



1—1 

£ 

£ 

£ 


> 



aj 

H 

•1— 1 

•rH 

w 

•rH 



P 


fad 

N 

H 

p 


P 

£ 

>3 

faD 

aj 

aj 

rH 


0 

P 

1 - 1 

Q 

P 

O 

£ 


0 

a? 

P 


CO 

K 

O 


n 

S 

a 





P 



0 





0 



P 





■£ 



•rH 





P 



Q 





O 




48 


Total 1,790 100 0.44 Avg. 



































The sediment yield caused by grazing is about 460 acre-feet per year, 
which is 26 percent of the total sediment from sheet and gully erosion 
in the Southern Basins. Although sediment yields from grazing and 
logging are similar, the sediment rate caused by grazing is only about 
one-fifth of that from logging. This rate is higher in the Mendocino 
Coastal Basin than in the other two. Grasslands in this basin are 
generally heavily grazed, especially in the Mattole Subbasin. The 
basin has large areas of unstable geology and soils, and the seasonal 
rainfall is higher than in the other two basins. 

Deer use and natural causes contribute about the same amount of sediment 
yield, each accounting for about l8 percent of the volume from sheet and 
gully erosion. The sediment rate for deer use is a little higher than 
that attributed to natural causes since it occurs over a smaller area. 

Roads in the Southern Basins are yielding only about 7 percent of the 
sediment from sheet and gully erosion. A higher proportion of roads 
are surfaced in the Southern Basins than in the Northern Basins; they 
have generally been established for a longer period and are usually 
located on flatter terrain. 

Cultivation is a minor cause of sediment yield, accounting for about 
60 acre-feet per year, which is about 3 percent of the total from sheet 
and gully erosion. Although the sediment rate from cultivation is about 
the same as some other causes, it occurs on a smaller area. 

Northern Basins 

For the 10,795 _ square mile area in the Northern Basins, the average 
sediment rate from sheet and gully erosion is 0.11 acre-feet per 
square mile per year, which accounts for 21 percent of the total sedi¬ 
ment production from all sources. The Trinity Basin has the highest 
sediment rate from sheet and gully erosion, with 0.22 acre-feet per 
square mile per year, followed by the Smith Basin, with 0.09 acre-feet 
per square mile per year, and the Klamath Basin, with 0.07 acre-feet 
per square mile per year. The percentage of sediment yield from sheet 
and gully erosion for each cause is as follows: roads - 62 percent, 
natural erosion - l6 percent, logging - l4 percent, grazing - 6 percent, 
and deer - 2 percent. 

The following table "Present Sediment Yields from Sheet and Gully 
Erosion in the Northern Basins" shows the annual sediment yields for 
each basin by cause. The accompanying table "Present Sediment Rates 
from Sheet and Gully Erosion in the Northern Basins" shows the annual 
rates per square mile for each cause. 

The sediment rate per square mile of area disturbed by roads is con¬ 
siderably higher than that yielded by other causes of sheet and gully 
erosion. The average annual sediment rate from road prisms in the 
three basins is about 16.5 acre-feet per square mile ( 0.08 acre-feet 
per mile), which is about 13 percent of the total sediment yield from 
all sources and about 62 percent of that from sheet and gully erosion. 


49 









G 

>H 


r—I 
i—1 

3 


G 

G 


m 
G 

• i—i 

+3 w 
G eg 

g m 

nG 

co G 
G 

S G 
O X! 
G P 
P G 
O 

ra P 
"G 

i—1 CLJ 

CD ,G 
•H P 


>n 

p 

G 

U 

•(—I 


TCi M 
CD O 
CO G 

P W 
G 
CD 
W 
CD 
G 
Ph 


1—1 

O 

O 

o 

o 

G 

o\ 

P- 

p- 

CO 

P 

O 

EH 

-G" 

vo 


CM 

c\ 

I—1 


O 
ctS LG- 
G 
C5 


O 

P- 


VO 

CO 

O 

c\ 

tP 


CD 

O 

G 

G 

Eh 


O 

no 


O 

G\ 


OV 

VO 

D\ 

CM 


CD 

O 

G 

G 

Eh 


CD 

O 

G 

G 

EH 


CD 

O 

G 

G 

Eh 


O 


o 

tp 


o 

cr\ 

p- 


o 

p- 

I—I 


LT\ 

o\ 

t>- 

o' 


I —1 

I—I 

3 

Tj W 

G G 


P 

G 


w 

CD CD 
P rG 
G P 
P 

G 

p -H 


CD G 

g o 

•H *H 

w 

CD O 
CO G 
P 
P 
G 
CD 
m 
CD 


G 

G 

CD CD 
P P 
G p 
K S 


cr 1 

CO 


i—1 





•H G 

G 



G 


Ti G 

G 

o 

o 

u 

O 

G P 

G 

CM 

CO 

G 

O 

CO 1 

P 

I—1 


G 

CM 

G 

M 



EH 


G 

P 





O 






C 







G 



G 



G 

o 

o 

O 

O 


G 

1—1 

CM 

G 

CO 

^-S 

n 



G 


P w 




EH 


G G 


P P 
O -H 
CD S 
P 

P CD 

^ s 

G G 
CD cG 
G CO 
< '~p 






G 


I—1 






P G 

P 

G 






CO G 

G 

P 






G 

G 

O 

VO CM 

O 

O 

o 

O 

g p 

o 

EH 

i—1 VO 

LTV 

LTV 

VO 

VO 

O P 

G 



CM 

-G" 


P- 

G G 

G 

P 






P O 

p 

O 



'G G 
i—1 G 
G G 
•H pi 
>H\ 
P 
P G 
G G 
G P 
g I 

•H G 
P G 
G O 
CO < 






P 

P 

P 

P 


p 

P 


O 

O 

G 

I-1 


p 

P 


EH 


G 

P 

G 

G 

•H 

P 


G 

£ 

O 

•rH 

£ 

G 

P 


ra 

•H 

G 

m 

G 

•iH 

•r—1 


G 

P 

G 

ctf 

i—i 

G 

£ 


G 

G 

•H 

PQ 

P 

EH 

CO 


O 

CO 

Q 


P 

P 

l 

V 

C 

CO 

o 

o 


C— i—I G 
P O Lf\ O 

• • • G 

O O VO G 

P Eh 


O LTV vO P- 
W O J-VO 
O P -G" 

P LTV 


>? 

m 

'G 

G 

O 

G 

G 

G 

i —1 

P 

G 

P • 


bO hO 
G G 

•r—I *rH 

W N "G 


G 

o 

•H 

p 

G 

t> 

•H 

p 


- G 
GOG 
CO K O 


G CM 
O O 
G 
G 
EH 


O 


hO 

P 

< 

■—l 
■—1 

o 


-G- CO 
O OV 
P P- 
*\ «~\ 
VO o 


CM VO 

i—i 


o 

o 

I—I 


O 

o o 

o 

O O 

O 

P- 

P-VO 

G 

CO O 

CO 

i—1 

p- 

G 

CM 

CM 



EH 


i—! 


G 

G 

P 

P 

O 


G 

G 

G 

n 


i—i 

G 

P 

O 

EH 


50 



































Land slippage ccnd roadside erosion. i SCS PHOTO 3-2220-10 


Eroding roadside ditch causing slides on the roadcut. 


51 






The Trinity has the highest sediment yield caused by roads, followed by 
the Klamath and Smith Basins. Road and stream densities are greater in 
the Trinity Basin, which probably accounts for its higher yield. The 
Smith Basin yielded less total road-caused sediment, but has a sediment 
rate greater than the Klamath. Higher stream density and rainfall are 
probably responsible. 

In the Trinity, Smith, and Klamath Basins, roads in the national forests 
accounted for 9 ^-, 85 , and 76 percent, respectively, of the total road- 
caused sediment yield. The chief source of sediment is unstable cut 
banks, which are necessarily wide in steep terrain. Many national 
forest roads are new and have not had time to revegetate and otherwise 
stabilize. Terrain in the national forests is generally steeper and 
has more unstable rock and soil mantle than in the areas outside the 
boundaries. National forest road maintenance is often inadequate 
because funds for this purpose seldom keep pace with those for road 
construction. Most of these roads are unsurfaced, and surface erosion 
is an added minor problem. 

An analysis of field data on roads within national forest boundaries was 
made to ascertain the effect of the nearness of roads to streams. One 
hundred feet was selected as the sample dividing point, and maps show 
that about one-third of the roads are within that distance. It was 
found that roads closer than 100 feet yielded about 2-l/2 times more 
sediment as those further away. This is attributed to erosion of fill 
materials during floods and surface erosion that directly enters stream 
channels. 

Natural erosion is the second largest cause of sediment yield from sheet 
and gully ersoion. This is considered to be mostly a result of high- 
rainfall and unstable soil and geological conditions. 

Logging ranks third among the causes of sediment yield from sheet and 
gully erosion. Sediment rates from erosion caused by logging are 
slightly higher in the Trinity than in the Klamath and Smith Basins, 
which have about the same rate. Logging in the Klamath and Smith 
Basins is done primarily with high lead methods, while in the Trinity 

Basin, tractor logging is the most common system used. Tractor logging 

generally causes greater disturbance of the soils and requires more roads, 
many of which must be located on the lower slopes near streams. 

Sediment yield caused by grazing is a minor problem in the Northern 
Basins. Total yield is only about 70 acre-feet, which is based upon 

a rate of 0.01 acre-feet per square mile per year for the area grazed. 

Virtually all of the yield is in the eastern part of the Klamath Basin; 
other grazed areas showed only a trace of erosion. The effect of deer 
use upon sediment yield is also very slight, with rates of only a trace 
basinwide. Cultivation occurs mainly on the nearly level valley soils, 
and sediment yields from this cause are too slight to measure. 

FUTURE SEDIMENT YIELD 

Sediment yields from sheet and gully erosion are expected to increase 
from 1,230 to 1,330 acre-feet per year in the Northern Basins and from 


52 





1,790 to 2,690 acre-feet per year in the Southern Basins during the 
next 50 years if the proposed land treatment program is not installed. 

These estimates are projected from past sediment rate increases found in 
sample data and are modified according to some assumptions regarding the 
future uue and management of the basins. 

Since the Northern Basins have a high proportion of national forest land, 
the sediment rates will probably decrease because of continually improv¬ 
ing management practices. At the same time, however, increased public 
use will tend to offset this decrease. For example, improvement in road 
design, construction, and maintenance may result in lower erosion 
rates, but the increasing public use will require more miles of road. 
Although sediment rates will decrease, the net sediment yield will not 
necessarily be reduced. 

Management on private lands will also probably improve over the next 
50 years as land becomes more valuable, more laws are passed control¬ 
ling use, and traditional management practices that are often wasteful 
are changed by better informed managers. The public is becoming more 
cognizant of destructive management, and this attitude should result 
in more restrictions on private land use, especially where timber har¬ 
vest is concerned. However, many areas, particularly in the Southern 
Basins, have been abused to the point where sediment yields will remain 
high for many years. This is especially true for heavily gullied areas, 
which are almost impossible to heal through rehabilitation programs 
and which heal very slowly under natural conditions. 

Grazing use in national forests is decreasing, and this trend is expected 
to continue in the future. The Forest Service will limit grazing on 
most of the badly abused areas, and these will slowly rehabilitate them¬ 
selves, with or without the application of special programs. In areas 
where grazing is to be continued in the national forests, livestock 
numbers are being brought into balance with the capacity of the resource. 
Sediment yield from all national forest grasslands should remain negli¬ 
gible . 

On private lands, the grazing situation is quite different. Although 
some improvement in management is needed and expected, it is assumed 
that many areas will continue to be overgrazed, particularly in the 
Southern Basins. There are presently many grassland areas that have 
deteriorated through continued heavy use to the point that they cannot 
recover without remedial programs. Sediment yields on these areas are 
expected to increase at an accelerated rate unless remedial programs 
are installed. 

Considering all these factors, it seems logical to predict that sediment 
yields from sheet and gully erosion will increase if remedial programs 
are not installed and management guidelines are not followed. This 
increase is projected to be about 100 acre-feet per year in the Northern 
Basins and about 900 acre-feet per year in the Southern Basins by the 
year 2020. 


53 






IANDSLIDE EROSION 


Landslides are prominent features of the landscape in the basins and 
are one of the most visible sources of sediment yield. A prime example 
of their prominence can be seen along Highway 101 from Cloverdale to 
Hopland, which is repeatedly being repaired because of slide activity. 
Because of this prominence, slides are frequently cited as the major 
mode of landscape degradation as well as the major source of sediment 
in the basins. However, this study shows that landslides rank second 
as a source of sediment yield in the Northern Basins and rank third 
in the Southern Basins, contributing 31 and 19 percent, respectively, 
of the total sediment yield from all sources. 

AVAILABLE DATA 

The only specific data found on landslides in this area are contained in 
the Corps of Engineers report on landslides around the margin of Lake 
Sonoma behind the Warm Springs Dam in the Russian River Basin .±J Other 
sources of available data consisted of published reports on the geology 
of specific areas, ground water reports, and broad reconnaissance studies, 
in which landslides were briefly mentioned. General geology of the 
basins is shown on the Ukiah, Santa Rosa, Redding, Weed, and Alturas 
Sheets of the Geologic Map of California published by the State Division 
of Mines and Geology. 

Aerial photographs taken in 1940, 194l, 1942, 1944, 1947, 1948, 1953, 

1965 , and 1968 and the latest editions of U.S. Geologic Survey Topo¬ 
graphic Quadrangles were used extensively. 

SURVEY PROCEDURES 

Engineering and geological literature abounds with definitions of land¬ 
slides, but the consensus seems to define a landslide as the downward 
movement of slope-forming movement of slope-forming materials, such as 
rock and soil. For this study, two criteria had to be met in order 
that a slide could be tabulated, (l) it had to be visible on a standard 
1 : 20 , 000 -scale aerial photograph and ( 2 ) it had to be actively pro¬ 
ducing sediment. 

Many spectacular landslides can be seen from roads that traverse the 
basins, but many more occur in remote canyons, so it was necessary to 
use aerial photographs. Since it was impractical to examine all the 
photographs, a sampling technique was devised, by which about 10 per¬ 
cent of the area was examined on aerial photographs. In the Clear Lake 
Basin, about 40 percent of the area was examined to assure adequate 
coverage because few landslides were found. Landslide data measured or 
estimated from aerial photographs were checked in the field for accuracy 
when possible. 



Corps of Engineers, Russian River Basin, Dry Creek; Warm Springs Dam 
and Lake Sonoma Project, Sonoma County, California , Design Memorandum 
No. 9, Geology, pp. 26-35- (San Francisco, August 1967 .) 


54 








I 



Large landslide in the Bean Creek Watershed s Humboldt County. 

SCS PHOTO 3-5736-1 



Active landslide causing road damage as well as sedimentation 
in Big Sulphur Creek 3 Sonoma County. photo s-sise-n 


55 





Annual sediment yield for each sample was determined by dividing the 
volume of sediment lost during the time span between two aerial photo¬ 
graph flights by the number of years in that period. Photographs taken 
in 1965 were compared with those taken variously in 1940 , ' 42 , ' 44 , ' 48 , 
and ' 53 * Consequently, the period between flights varied considerably 
over the study area. This could produce discrepancies in the results 
because differences in precipitation and runoff which affect sliding, 
occurred during the various periods. To counteract this potential 
bias, adjustments were made by correlating annual runoff data for the 
various time spans, using 1940-65 as the base period. No adjustments 
were needed for the Northern Basins, and only slight adjustments were 
made for the Southern Basins. 

Other information recorded for each sample slide included interpretations 
of geology, probable causes of the slide, and possible remedial measures. 

The smallest slide that could be adequately studied was found to be 200 
feet in one dimension, which appears as a tenth of an inch on aerial 
photographs with a scale of 1:20,000. Slides smaller than 200 feet in 
one dimension were included in the studies of sheet and gully and stream- 
bank erosion. 

DATA ANALYSIS 

The volume of material yielded by slides was tabulated and the area 
covered by each photo was determined. The average annual sediment rate 
per square mile for the samples in each subbasin was determined, and 
the weighted average rate was applied to the entire subbasin area to 
obtain the average annual sediment yield for that subbasin. 

FINDINGS 

As shown in the following table, "Present Sediment Yields and Rates 
from Landslides," the sediment yield from the Northern Basins is nearly 
double that in the Southern Basins. However, the Southern Basins 
have a sediment rate about 25 percent higher than that in the Northern 
Basins. The Nkttole River Subbasin of the Mendocino Coastal Basins 
has the highest rate, 0.80 acre-feet per square mile per year, followed 
by the South Fork Trinity Subbasin of the Trinity River Basin, with 0.6l 
acre-feet per square mile per year. The Clear Lake Basin showed the 
lowest rate, 0.02 acre-feet per square mile per year. 

Southern Basins 


The low yield for the Southern Russian Subbasin and Clear Lake Basin 
can probably be attributed to topographic and geologic factors. Much 
of the Southern Russian Subbasin is flat or gently rolling, and the 
mountains in the eastern part are underlain by the resistant Sonoma 
volcanics. To the west the terrain and geology are typical of the 
unstable conditions in the North Coastal Area, but the only major 
landslides observed were in the Austin Creek watershed north of 
Cazadero. 


56 









Present Sediment Yields and Rates From Landslides 


Basin or Subbasin 


Annual 

Sediment 

Drainage Area Yield 

(Sq. Miles) (Acre-Feet) 


Annual 

Sediment 

Rate 

(Ac.Ft./ 
Sq. Mile ) 


Southern Basins 


Russian River Basin 


Northern Russian 

1,010 

160 

0.16 

Southern Russina 

475 

20 

o.o4 

Subtotal 

1,485 

180 

0.12 

Mendocino Coastal Basin 

Mattole 

499 

4oo 

0.80 

Central Mendocino 

666 

120 

0.18 

Southern Mendocino 

933 

230 

0.25 

Subtotal 

2,098 

750 

0.36 

Clear Lake Basin 

458 

10 

0.02 

Total 

4,o4l 

940 

0.21 avg 


Northern Basins 

Klamath River Basin 

Butte Valley-Lost River 

2,309 

- 

- 

Salmon-Scott-Shasta 

2,199 

180 

0.08 

Middle Klamath 

1,756 

580 

0.33 

Mouth of Klamath 

772 

160 

0.21 

Subtotal 

7T03£ 

920 

0.13 

Trinity River Basin 

Upper Trinity 

1,013 

60 

0.06 

Lower Trinity 

1,024 

100 

0.10 

South Fork Trinity 

932 

570 

0.6l 

Subtotal 

2,969 

730 

0.25 

Smith River Basin 

790 

200 

0.25 

Total 

10,795 

1,850 

0.17 avg 


57 



























Nearly half of the Clear Lake Basin of the watershed is underlain by 
the erosion-resistant Clear Lake Volcanic Series, alluvium and other 
gently rolling or flat lands, and Clear Lake. Landslides in these 
areas are, for all practical purposes, non-existent, and nearly all the 
slides found were in the other half, the mountainous western and 
northern parts. 

The major areas of landslide activity in the Northern Russian Subbasin 
are Dry Creek, Big Sulphur Creek, and stretches along Highway 101 north 
of Ukiah and between Cloverdale and Hopland. The Franciscan formation, 
noted for its inherent weakness and erodibility, underlies most of these 
areas. In Big Sulphur Creek, faults are common and geysers are present, 
indicating geologic instability. 

Part of the variations in sediment yield among the subbasins is due to 
climatic differences. Mean annual rainfall in the Southern Russian Sub¬ 
basin and Clear Lake Basin is a moderate 30-50 inches per year, whereas 
the range in the Mattole Subbasin is 50-120 inches per year. This high 
rainfall, combined with weak rocks and steep topography, creates an 
especially significant landslide hazard in the Mattole Subbasin. 

Faulting is also a major cause of landslides, and many active slides 
are found along the San Andreas Fault in the Southern Mendocino Subbasin. 

Northern Basins 

As the table shows, some subbasins of the Klamath have very low sediment 
yields from landslides. For example, no slides were seen on any of the 
sample photos examined in the Butte Valley-Lost River Subbasin. Most 
of this subbasin is flat or gently rolling and is underlain by erosion- 
resistant lavas. This is an area of low precipitation, most of which 
falls as snow, and drainage of the subbasin is characterized by marshes, 
lakes, and sluggishly flowing streams. 

The Salmon-Scott-Shasta, Upper Trinity, and Lower Trinity Subbasins also 
experience a relatively low frequency of slides. Although they have 
rugged topography, rock formations are generally resistant to sliding. 
Debris slides and avalanches in the glacially sculptured valleys of the 
Trinity Alps and Marble Mountains account for considerable sediment in 
some of the smaller glacial streams of these areas, but they are rela¬ 
tively unimportant in the Klamath Basin. 

Landslide sediment yield in the South Fork Trinity Subbasin is the 
highest of any of the Northern Subbasins. It is estimated that land¬ 
slides account for 570 acre-feet of sediment per year in this subbasin. 
Mach of this area has steep terrain that was logged with little apparent 
regard for erosion control. 

One of the most devastated areas in the entire basin is a tractor logged 
area of privately owned land around Pelletreau Creek, where large slides, 
bank erosion, and gullies are found. An extremely large debris fan has 
formed at the mouth of Pelletreau Creek. A similar situation exists 
on privately owned land that was tractor logged in the watershed of Goose 


58 








Creek, a tributary of the South Fork of the Smith River. However, no 
large fan was observed at the mouth of Goose Creek, probably because 
of the flushing action by the South Fork Smith River. 

CAUSES OF LANDSLIDES 

Landslides take place under the combined influence of land use practices 
and geologic, topographic, and climatic conditions. These conditions 
can lead to sliding either by contributing to high shear stress on the 
slope, such as that caused by the removal of the toe of a slope by 
stream or road undercutting, or contributing to low shear strength in 
the rock or soil mass, as in the examples of faults, joints, and high 
water content. Removal of the toe of a slope by stream erosion or 
road construction may appear to be the most evident cause of a particular 
landslide, but it may be only the last link in a chain of events lead¬ 
ing to the failure of the slope. 

From any land management point of view, the identification of landslides 
by probable cause is a useful and necessary assessment. Assuming that 
unstable slopes in the basins are now in a delicate state of equilibrium, 
any condition that causes the slope to fail can be considered the pri¬ 
mary cause of a slide. 

The apparent primary causes of landslides were determined from aerial 
photographs and were verified for those slides that were checked in the 
field. These causes can be grouped into two categories -- those assoc¬ 
iated with man's activities and those occurring under natural conditions. 
Roads and logging were the main activities of man that could be iden¬ 
tified as influencing landslides, and the effect of these activities 
were easily detected on aerial photographs. The influence of grazing 
and man's other activities could not be easily identified from the 
photographs. 

Most of the sediment yield from landslides is attributed to natural 
causes, the most common of which is undercutting by streams. Stream- 
caused sliding may be aided by other factors, such as spring seepage, 
location on a fault zone, and heavy precipitation. Slides not incident 
to streams can sometimes be attributed to gullying. In many cases, the 
primary cause of sliding is not evident from the aerial photographs. 

In some areas, especially in the Klamath Basin, sliding may be attri¬ 
butable to unnaturally high stream flows indirectly caused by logging 
activities upstream. Stream courses in these areas are characterized 
by bare, raw channels where the natural streambank vegetation has been 
washed away. Landslides in these areas are caused by stream undercut¬ 
ting, but may be influenced by logging operations. 

The percentage of man-caused landslide sediment yield varies widely 
among the basins, as shown in the following tabulation. 


59 



Basin 

Annual 

Sediment 

Yield 

(Acre-Feet) 

Directly 
Man-Caused 
(Percent) 

Indirectly 
Man-Caused 
(Percent) 

Natural 
Causes 
(Percent) 

Klamath-Trinity- 

Smith 

1,850 

12 

33 

55 

Russian 

180 

6 

- 

94 

Mendocino Coastal 

750 

12 

- 

88 

Clear Lake 

10 

1 

10 

89 

FUTURE SEDIMENT YIELD 




Unless effective 

land treatment 

programs are 

introduced, sediment yield 


from landslides will increase,in the future because of construction and 
development brought on by the demands of an increased population. In 
the next 50 years, a sediment yield increase of 25 percent is estimated 
under these conditions. 


STREAMBANK EROSION 


Streambank erosion is defined as the removal of bank material by erosive 
stream action and includes small landslides that are less than 200 feet 
wide, measured along the stream. This sediment source yields about 
5,080 acre-feet per year from the basins or about 47 percent of the total 
yield. 

AVAILABLE DATA 

The following material was available for use in determining the sedi¬ 
ment yield from streambanks: 

1 . U.S. Geological Survey Topographic Quadrangles (scales 
1:62,500 and 1 : 24 , 000 ). 

2 . Aerial photographs: 1940 , 1941 , 1942 , 1944 , 1946 , 1948 , 1952 , 
1965, and 1968 flights (approximate scale 1:20,000). 

SURVEY PROCEDURES 

Because of the large number of streams and the variation in sizes, a 
sampling technique was used in selecting streams to be studied. 

Streams were classified by order, in accordance with Strahler's 


60 













Streambank erosion along the Trinity River. 5CS PHOTO 3-5735-13 



Streambank erosion along the Russian River. SCS PHOTO 3-5258-6 


6l 


modificati.oni/ of Horton's stream ordering system. A description of 
this system is presented in Appendix No. 1 for the Eel and Mad River 
Basins. 

The number of samples for each stream order was determined in relation 
to its total length, and specific streams to be sampled were selected 
on topographic maps. These sample streams were studied under stereo¬ 
scope on 1965 aerial photographs for all basins except Clear Lake, for 
which 1968 photographs were available. After viewing photographs of the 
sample streams, individual reaches to be studied were selected. A rela¬ 
tively unobstructed view of the sample site on the aerial photograph was 
an important consideration. Sample reaches averaging one mile in length 
were measured. The stream area in the bottom or at the top of eroded 
banks, whichever was most visible, was delineated on the aerial photo¬ 
graph and measured by planimeter. An Abrams height finder was used to 
determine the average height of some eroded banks, while others were 
estimated. 

This process was repeated for the corresponding sample reaches on the 
oldest aerial photographs available. In the Northern Basins, 1944 photo¬ 
graphs were available for 75 percent of the area, and 1942 and 1946 
photographs were used for the remainder of these basins. In the Russian 
and Mendocino Basins, 1941 aerial photographs were available for about 
one-third of the area, and 1948 and 1952 photographs were used in the 
remaining area. In the Clear Lake Basin, 1940 aerial photographs were 
used. The streambank volume that eroded during the time between aerial 
flights is the difference in channel area times the average depth of the 
same reach. The average annual sediment yield was computed for each 
sample reach. 

Of the 32,270 miles of stream in the six basins, about 602 miles or about 
2 percent of the total were sampled. 14)st of the samples were checked in 
the field to assure that they were typical and that the measurements were 
reasonably accurate. Many other stream reaches were observed in the field 
for comparison with the sample reaches. 

DATA ANALYSIS 

Since there was a possibility that the average annual sediment yield 
could vary for the several time periods, 1941-1965, 1944-1965, 1946-1965, 
1948-1965, and 1952-1965, it was necessary to make a comparison of sus¬ 
pended load and streamflow gage records to see if the estimated rates 
needed adjustment. The procedure used to make this comparison is de¬ 
scribed in the Appendix No. 1 for the Eel and Mad River Basins. Results 
of the comparison for the Northern Basins showed that the rates for the 
1942-1965 and the 1946-1965 periods varied only slightly from that for 
the 1944-1965 period, so no adjustment was made for the other two periods. 
For the Russian and Mendocino Basins, the difference was significant, 
and the data for the 1948-1965 and 1952-1965 periods were adjusted to 


Kenneth L. Bowden and James R. Wallis, "Effect of Stream-Ordering 
Technique on Horton's Laws of Drainage Composition." Geol. Society 
of America , Bulletin, Vol. 75, PP* 767-773 (1964). 

62 











correspond with that for 1941-1965. In the Clear Lake Basin, the 
1940-1968 period was essentially the same as that for 194-1-1965, so 
no adjustment was made. 

For each stream order and subbasin, both the sample lengths, in miles, 
and the sediment rates of the samples, in acre-feet per year, were 
totaled. The aggregate sample of sediment yields was divided by the 
total sample length to arrive at an average sediment rate per mile for 
each order and subbasin. The average sediment rate per mile was 
multiplied by the total length of streams for that order and subbasin 
to obtain the final sediment rate in acre-feet per year. 

PRESENT SEDIMENT YIELD 

In general, streambanks in the Northern Basins are yielding less sedi¬ 
ment per square mile than those in the Southern Basins. Except for 
the eastern side of the Klamath Basin, the Northern Basins are mainly 
comprised of steep mountainous terrain with shallower soils, are 
forested and brush covered, and have more stable geologic formations 
over a larger portion of the area. Heavily forested and brush covered 
areas generally provide better protection against streambank erosion. 
Although over half of the Southern Basins are forest and brushlands, 
the areas of grass and cropland are substantially larger than in most 
of the Northern Basins. Terrace material and alluvial valleys found 
in range and cropland areas have deeper soils, and streambanks located 
in these areas are more subject to erosion. 

Although the erosion rates per mile for 2nd and 3rd order streams are 
much smaller than those for the higher order streams, their sediment 
yield is about half of the total from streambanks because of their 
greater lengths. These smaller streams represent about 70 percent of 
the total length of all streams. 

In general, the sediment rates per square mile increase in the larger 
stream orders partially because they carry more flow, but also because 
stream channels generally become flatter and are located in succeedingly 
more terrace and alluvial fill material as they approach the mouth. 

These sources of erodible material appear to yield the greatest amount 
of sediment per mile. In a few cases, larger stream orders are yield¬ 
ing less sediment per mile than the smaller ones in the same basin, 
probably because the larger ones have low banks, rockbound reaches, 
or good vegetal protection. 

Southern Basins 

The results of the present sediment yield studies on streambanks in 
the Southern Basins are presented by stream order and subbasin in the 
tables "Present Annual Sediment Yield from Streambanks," "Length of 
Stream Channels," and "Annual Sediment Rate Per Mile of Stream," on 
the following pages. In these basins, streambank erosion yields about 
40 to 54 percent of the total sediment. 


63 






Present Annual Sediment Yield From Streambanks 
In The Southern Basins 



CYI 

A- 

1—1 

o 

OA 

o 

00 


LT\ 

VO 

ua 

VO 

1—1 

CvJ 

LTN 

UA 

cu 

UA 

• 

• 

• 

• 

• 

• 

• 

• 

• 

o 

o 

o 

1—1 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

PO 

A- 

o 

LTV 

CA 

A- 

1—1 

1—1 

cu 

VO 

CVI 

CA 

LTV 

1—1 

J- 

C\J 

CA 

1—1 

<-l 

cu 

CA 

cu 



i 


i 


p 

O) 

<u 

IP 


(U 

£ 

O 

< 


tJ 

i—I 

cu 

•pH 

lx 

P 

£ 

I 

•H 


W 

£ 

cu 

Ti 

£ 

o 

£ 

cd 

(D 

£ 

-P 

CO 


PZl 

0 ) 

02 



o 

o 

o 


o 


o 

£ 

o 

-p 

A- 

cu 

OA 

1 

1—1 

1 

1—1 

EH 

o 

A- 


1 —1 

1—1 






cu 

,£ 

O 

o 

o 


o 

o 

o 

o 

o 

-p 

CA 

1—1 

o 

1 

1—1 

VO 

A— 

PO 

o 

V0 


r—1 






cu 

X 

O 

o 

o 

o 

o 

o 

o 

o 

o 

-p 

VO 

1—1 

a- 

CO 

pj- 

0O 

UA 

cu 

pA 

UA 



1—1 



cu 


PO 

,£ 

o 

o 

o 

o 

o 

o 

o 

o 

o 

-p 

CO 

cu 

o 

A- 

cu 

cu 

1—1 

PO 

pA 

pf 


1 — 1 



1—1 

cu 


PO 

TJ 

o 

o 

o 

o 

o 

o 

o 

o 

o 

£ 

pj- 

VO 

o 

CO 

CO 

CA 

o 

1—1 

1—1 

CO 

i—1 

cu 

1—1 



PO 


UA 

TZf 

o 

o 

o 

o 

o 

o 

o 

o 

o 

£ 

CA 

LTV 

Pt 

c — 

CO 

cu 

A- 

cu 

PO 

CU 

r—1 


cu 

1—1 


1—1 

PO 


VO 


LfA 

L 1 A 

CA 

VO 

PO 

0O 

CO 

A- 

00 

0 A 

VO 

PO 

0 A 

UA 

Pt 

PA 

CA 

pH 

PA 

VO 

OA 

o 

cu 

PA 


£ 




cd 

£ 


• r~\ 

•H 


CO 

M 


CO 

£ 


2 

X 

£ 

p^ 

P 

o> 


£ 

i> 

( — 1 

02 

• 1—1 

£ 


K 

cu 

£ 


r£ 

o 

£ 

p 


cd 

£ 

£ 

•H 

o 

•t —1 

CO 


co 

CO 


cd 

2 


pq 








o 

£ 




£ 

cd 




•r—1 

• iH 


I—1 


o 

w 


£ 


o 

w 


-P 


TZJ 

£ 

i—1 

w 


£ 

K 

cd 

cd 


cu 

p 

O 


S 

£ 

o 

O 



£ 

p 


<u 

i —1 

0) 

X 

O 

I—1 

cd 

X 

£ 

£ 

o 

£ 

-P 

02 

•i—1 

-p 

P 

£ 


o 

p 

£ 

O 


o 

a 

CU 

02 


T) 

s 

O 



0) 





S 




o 

£ 
• H 


O 

o 

TZ) 


0) 

,£ 

-P 

£ 

o 

CO 


cd 

p 

o 

-p 

CO 


CU 




cd 


P 


£ 

1—1 

cd 

cd 

cu 

p 

i—l 

o 

o 

Eh 


64 










































Length of Stream Channels 
In The Southern Basins 




W 











1 —1 

0 

O 

O 

O 

0 

0 

0 

O 



aj 

00 

IP 

O 

av 

ov 

00 

VO 

CM 



p 

p- 

O 

LTV 

OV 

LTV 

1—1 

p 

P 



O 

c\ 

#> 

*"N 


«N 

0 

r\ 




EH 

CVI 

1 — 1 

CO 


1 - 1 

CM 

p 




P 











+0 

1 

1 

1 

1 

1 

1 

1 

1 



av 











P 











p 

1 

1 

1 

1 

1 

1 

1 

1 



CO 









w 











aj 











1—l 


p 

0 

O 

O 

1 

O 

1 

0 

In 

•rH 


p 

00 

VO 

o\ 


CO 


00 

EH 



IP 









,£ 

p 


p 

0 

O 

0 

, 

O 

O 

0 

O 

W) 

£ 

p 

tp 

1 - 1 

CO 


OO 

VO 

a\ 

CM 

£ 

0 ) 

VO 









CD 

Tj 










PI 

£ 

O 










B 

p 

0 

O 

0 

0 

O 

O 

0 

O 

aj 

B 

-p 

VO 

P 

0 

LTV 

00 

CM 

LTN 

CO 

(D 

a 

LTV 



1—1 



1 —1 

CM 


£ 

<d 










P 

£ 










co 

-P 











co 

P 

0 

O 

0 

O 

0 

O 

O 

O 



-P 

CO 

P 

LPv 

P 

On 

O 

VO 

CTv 



-£~ 

1 —1 


CVI 



CM 

OO 





O 

O 

O 

O 

O 

O 

O 

O 




00 

O 

CO 

O 

co 

P 

CM 

LTV 



£ 

ir\ 

CVI 

p 

CM 

00 

P 

O 

1 - 1 



on 







C\ 











1—1 





O 

0 

0 

O 

0 

O 

0 

O 



p 

VO 

o\ 

LTV 

P 

CO 

VO 

1 — 1 

CO 



a 

LTV 

VO 

CM 

VO 

OV 

CO 

0 

P 



CVI 

C\ 





•> 






1 - 1 


CM 



1 — l 

CO 




w 











cd 











1 —1 

O 

LTV 

LTV 

o\ 

VO 

CO 

00 

00 


ctf 

•r~ 1 

1 —1 

P 

00 

OV 

VO 

CO 

CT\ 

LTV 


(L> 

S 

O 

P 

P 

p 

VO 

ov 

0 

P 


£ 

• 

r\ 






cs 



< 

U H 

l— 1 


1 - 1 




CM 



CO 


o 

o £ 




£ 

£ 




£ 

•rH 





aj 

aj 




•rH 

0 



£ 


•1— 1 

•rH 


1—1 


0 

0 



•rH 


w 

W 


aj 


0 

P 



w 


m 

M 


-P 


P 

£ 



aj 


£ 

£ 

rH 

w 


£ 

CD 

1 — l 


P 

£ 

K 

K 

aj 

aj 


CD 

S 

a3 


P 

(U 



-P 

O 


S 


-P 


2 

> 

£ 

£ 

O 

O 



£ 

O 


co 

•rH 

£ 

£ 

-P 


CD 

1 — 1 

£ 

P 

CD 



O 

0 ) 

P 

O 

1 — 1 

aj 

CD 

P 

p 

£ 


P 

P 

£ 

£ 

O 

£ 

P 

£ 

a3 

0 

£ 

P 

-P 

CO 

•rH 

-P 

-P 

P 

CO 

P 


aj 

£ 

£ 


0 

-P 

£ 

£ 



£ 

•rH 

O 

0 


0 

P 

a) 

O 


£ 

•1 — 1 

C/3 

!P 

CO 


P 

S 

0 

CO 


aj 

U1 

m 




£ 





CD 

aj 

2 




0 





1-1 

PQ 





s 





O 


65 


Total 4,04l 5,690 1,900 700 380 190 120 - - 8,980 









































Annual Sediment Rate Per Mile of Stream 
In The Southern Basins 


• (—1 CL) 
W fc)0 
ccj aj 

VO 

UN 

VO 

VO 

CM 

CVJ 

LTV 

LTV 

P P 

CNJ 

CM 

CM 

LTV 

1-1 

CVJ 

CVJ 

i—1 

P (U 

• 

• 

• 

• 

• 




^ t> 
CO < 

o 

O 

o 

o 

o 

o 

o 

o 

P 









P 

1 

I 

1 

1 

1 

i 

i 

1 

ON 









P 









P 

1 

1 

1 

1 

1 

i 

i 

1 

CO 









XI 

on 

o 

1 — 1 


oo 


oo 


p 

on 

o 

r—1 

1 

oo 

i 

oo 

Jh 

t— 

• 

« 

« 


« 


• 

EH 


C\J 

CVJ 

CVJ 


o 


o 



X! 

ON 

o 

UN 


CO 

o 

CO 

o 

-P 

CM 

o 

CM 

1 

oo 

o 

t— 

UN 

VO 

. 

. 

. 


• 





i — 1 

1 — 1 

1 — 1 


o 

1 — 1 

o 

i — 1 

P 

o 

UN 

O 

o 

o 

IN- 

o 

o 

P> 

o 

CM 

t- 

VO 

UN 

VO 

o 

UN 

LCN 

• 

. 

. 


• 



. 


1 — 1 

o 

o 

CM 

o 

o 

i—t 

o 

P 

-=f 

ON 

o 

O 

CM 

o 

CO 

oo 

-P 

-3* 

CM 

p- 

O 

CM 

VO 

UN 

oo 

P± 

• 

. 

. 

. 

. 


• 

• 


o 

o 

o 

i —1 

O 

o 

o 

o 

P 

VO 

o 

t— 

o 

CO 

o 

ON 

to¬ 

P 

CVJ 

CO 

CM 

ON 

o 

CM 

CM 

co 

OO 


• 

« 

• 

• 

e 

« 

• 


o 

o 

o 

o 

o 

O 

o 

o 

P 

CVJ 

E — 

1 — 1 

UN 

CO 

ON 

CM 

UN 

d 

1—1 

O 

1—1 

CM 

o 

o 

r— J 

o 

CM 

• 

• 

• 

. 

• 

. 

• 



o 

o 

o 

o 

o 

o 

o 

o 


vo 


UN 

o 


n- 

00 

o* 


on 

-d- 


o 


t- 

0J 

o 


i—I 
i —I 


o 


w 

dJ 

I—1 

a *h 

a; S 

p • 
<C a 1 

co 


O 

i—l 

o 


LT\ 

t>- 


ON VO 
ON VO 
Pt VO 


oo 

oo 

ON 


00 

UN 

PE 









•rH 

o 



w 

a 


•rH 

•i — 1 


i—1 


CJ 

o 



d 

•rH 


ra 

w 


d 


o 

P 



•rH 

W 


w 

w 


P 


P 

d 



w 

aj 



d 


w 


d 

da 



aj 

P 

P 

pH 

K 

d> 

aj 


p 

2 

d) 


m 

P 

0) 


W) 

O 


S 


bo 



d 

> 

d 

d 

aj 

O 



d 

aj 


p 

CO 

•H 

p 

p 

P 


CD 

i — i 

p 

P 

d) 

o 


Ph 

aj 

a; 

d) 

o 

i—1 

aj 

<u 

d) 

P 

Ph 

p 


P 

rd 

> 

d 

o 

P 

P 

> 

aj 


o 

d 

p> 

p> 

< 

•rH 

-p 

P 

p 

< 

PI 

dJ 


aj 

p 

d 

o 

p 

d 

d 


M 

d 

•rH 

o 

o 


o 

cti 

d) 

o 


P 

a3 

•rH 

w 

p 

CO 


P 

IS 

o 

CO 


aj 

P 

CO 

w 




d 





d) 

d> 

cd 

2 




p 





i—l 

i> 

PQ 

PP 




S 





o 

< 


66 


O.25 

































The Russian Basin has the highest sediment rate probably because it 
has a larger percentage of terrace material and flat alluvial valleys 
that are particularly subject to streambank erosion. The Northern 
Russian Subbasin has a slightly higher rate than the Southern Subbasin. 
Precipitation varies from about 30 to 60 inches over most of the basin, 
but this variation seems to be uniformly distributed in both subbasins. 

The Mendocino Coastal Basin has the next highest sediment rate from 
streambanks, only slightly lower than that for the Russian Basin. 
Considerable variations in rates occur between the subbasins of the 
Mendocino Coastal Basin. Geologic conditions in the three areas are 
generally similar, but annual runoff varies considerably. There is 
significant correlation between total sediment yield and runoff, and 
this same relationship appears to be true for streambank erosion and 
runoff. The Mattole Subbasin has the highest sediment rate (1.10 acre- 
feet per square mile per year) and the most annual runoff, ranging from 
30 to 90 inches. The Southern Mendocino Subbasin has the next highest 
sediment rate (0.50 acre-feet per square mile per year) and an annual 
runoff that varies from 15 to 40 inches. The Central Mendocino Subbasin 
has the lowest sediment rate ( 0.29 acre-feet per square mile per year) 
and the lowest annual runoff (15 to 30 inches). 

Clear Lake Basin has the lowest sediment rate from streambanks, about 
40 percent of that in the Russian Basin. Precipitation is much lower 
in this basin, varying from 22 to 40 inches per year. 

Northern Basins 


The results of the present sediment yield studies on streambanks in the 
Northern Basins are presented by stream order and subbasin in the 
tables "Present Annual Sediment Yield from Streambanks," "Length of Stream 
Channels," and "Annual Sediment Rate Per Mile of Stream" on the following 
pages. These yields account for about half of the total sediment in each 
basin. 

In the Klamath Basin, both the number of streams and the sediment rate 
per square mile from streambanks decrease in a west-to-east direction. 
Rainfall decreases in the same direction -- from 130 inches near the 
mouth to 10 inches inthe Butte Valley and Tulelake areas. Topography 
changes from steep mountainous terrain in the western portion to flat 
valleys and gently rolling to relatively flat plateaus in the east. 

The highest sediment yield from streambanks occurs in the mouth of the 
Klamath Subbasin, which has narrow alluvial valleys and unstable soil 
conditions on the highly erodible Franciscan formation. Much of this 
area has been tractor logged. Although the Middle Klamath and Salmon- 
Scott-Shasta Subbasins have mostly steep mountainous terrain, geologic 
formations in this area are generally more stable and resistant to 
erosion. Formations in the relatively level Butte Valley-Lost River 
Subbasin are mostly lava and other volcanic rocks that are highly 
resistant to erosion. 

The sediment rate in the Trinity Basin is about double that for Klamath 
Basin, mainly because the Trinity Basin has a proportionately larger 


67 




Present Annual Sediment Yield From Streambanks 
In The Northern Basins 


| 

I 



o 

o 

-d" 

OO 

CO 


o 

1 — 1 

C\J 

n- 

VO 

o 

CM 

C\J 

LT\ 

1—1 

on 

LTV 



0O 

CM 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 


CO 

i—! 

O 

o 

O 

o 

o 

o 

O 

O 

O 

O 

aj 

• — 1 


OO 

LTV 

OO 

LT\ 

i — l 

CO 

-G- 

o\ 

-P 



-4" 

-G - 

OO 

OO 

LTV 

OO 

CM 

CM 

O 

EH 





rs 

1 — 1 




c\ 

l—1 



o 

VO 

OO 

«\ 

CM 


o| 

M 


o 

t- 


o 

r- 


O VO 





o 

o 


O 


o 


O 

1 

l 

1 

OO 

oo 

1 

VO 

1 

VO 

1 

CO 


O 

o 


o 


o 

o 

o 


o 

l 

CM 

UO 

1 

t- 

1 

CM 

-G- 

VO 

1 

oo 

1—1 

G 

O 

O 


o 

o 

O 

o 

o 

o 

o 

Eh 

VO 

VO 

1 

CM 

UO 

CM 

to¬ 

-G - 

CM 

00 




1—1 




1—1 


CM 

G 

O 

O 

o 

o 

o 

O 

co 

o 

O 

o 

EH 

OO 

OO 

-G- 

o 

to¬ 

UO 


VO 

00 

-G- 





1—1 




1—t 


oo 

O 

O 

O 

o 

o 

co 

O 

o 

o 

O 

o 

1-1 

CT\ 

o 

VO 

VO 

-at 

OO 

oo 

UO 

UO 

VO 



1—1 


CM 




1—1 


-G - 

G 

O 

O 

o 

o 

o 

O 

o 

o 

o 

o 

EH 

1-1 

CO 

CO 

CO 

-at 

OO 

UO 

CM 

CM 

CM 


1-1 



CM 

1—1 

1-1 


OO 


VO 

G 

o 

o 

o 

o 

o 

o 

o 

O 

O 

O 

EH 

oo 

o 

c- 

o 

LTV 

LTV 

LTV 

UO 

CM 

to¬ 

1—1 

1—1 

1—1 

-at 


1-1 

i—i 

OO 

1-1 

co 


G 

CD 

G 

< 


G 

•H 

CO 

cti 

G> 

G> 

G 

co 

G 

O 

G 

•H 

W 

ai 

CQ 


G 

<L> 


i> 


•i—1 


K 

Gt 

-P 

I 

cti 


y 


CO 

CO 

VO 

o 

CO 

UO 

oo 

1 —1 

to- 

c\ 

«\ 


CM 

CM 

1 — 1 



cd 



-P 



co 



cd 



rG 



CO 

Gt 

1 

i 

-P 

!» 

-P 

25 

cd 

-P 

p 

i—1 G 

o 

cd 

i—1 CD 

o 

i—i 

cd > 

CO 

y 

> -H 




G 

CD 

CD 

Q 

i—1 

-P .p 

a 

T) 

-P W 

i—1 

T) 

G O 

d 

•rj 

PQ PI 

m 

S 


VO 

on 

-at 

CM 

GO 

O 

OO 

i — i 

CM 

OO 

VO 

CO 

O 

o 

O 

CO 

OV 

to- 

Cs 

#\ 

co 


*0 


0- 

i — i 

1-1 


CM 



-P 


Gt 





•rH 




-P 





G 




cd 





•( — 1 




s 




>5 

G 




cd 



-P 

•p 

EH 




i—t 

i—i 


•l — 1 

•H 


1—1 



y 

cd 

-p 

G 

CD 

.s 

.3 

y 

G 

ai 

-P 



4h 

O 

> 

G 

G 

O 

O 

G 

1—1 

O 

-p 

•iH 

Eh 

Eh 

Pi 

-P 

P 

CCS 


G> 

K 



G> 

> 

-p 

GJ 

3 


G 

G 

Gt 

G 

•H 

o 

-p 

CO 

>> 

CD 

CD 

-P 

CO 

k 

EH 

G 


•P 

Ph 

£ 

G 




o 


•rH 

Ph 

O 

O 


G3 


S 


G 

P3 

G3 

CO 


-P 




• r—1 





•rH 




G 





a 




EH 





CO 



68 














































Length of Stream Channels 
In The Northern Basins 


0 

O 

O 

0 

O 

0 

O 

O 

O 

O 

to 

OO 

10 

1—1 

00 

ft- 

-ft 


CM 

OO 

vo 

no 

UN 

no 

OO 

to- 

On 

-3" 

1-1 

CM 

#A 

*a 

•a 

•> 

«\ 

«A 

•A 

C 

•A 

«-> 

1-1 

-4* 


CU 

OJ 

I — 1 

CM 

CM 

CM 

OO 

CM 




ft 

p> 

ON 

ft 

p> 

00 

V) 



CD 


ft 

1—1 


-p 

s 


to 

ft 


ft 

p 

w 

p> 

hO 

d 

VO 

d 

0 


0) 

ft 


ft 

d 



O 

ft 

B 


p> 

cd 

B 

LTN 

0) 

a 


d 

CD 


-P 

d 


co 

-p 



CO 

ft 

-P 

-ft 

ft 

d 

no 

ft 

d 

CM 


cd 

CD 

d 

< 


Ol 

O 1 1 

1 1 1 I O 

1 




Ol 

O 

1 O 

1 I O 1 I 

1 O 

CM | 

CM 

no 

| no 

UA 



O 

O 


O 


O 

O 

0 


O 

1 

CM 

00 

1 

O 

1 

1 —1 

no 

-ft 

1 

_ft 





1-1 






1 —1 

O 

O 

O 


O 

O 

O 

O 

O 

O 

O 

CM 

00 

ON 

1 

ON 

to¬ 

VO 

UN 

co 

CM 

ON 





1-1 




1 —t 


no 

O 

O 

O 

O 

O 

co 

O 

0 

O 

O 

O 

-ft 

VO 

UN 

VO 

ft 

1—1 

CM 

0 

no 

Co 

*—1 





CM 

1—t 

1-1 

1—1 

no 


VO 

O 

O 

O 

O 

O 

0 

O 

0 

O 

O 

O 

CM 

CM 

OO 

UN 

[O 

CM 

OO 

I—1 

VO 

CM 

UN 

1 —1 

CM 

1-1 

1 —1 

VQ 

1 —1 

1-1 

1—1 

no 

1-1 

ft 











1—I 

O 

O 

O 

O 

O 

O 

O 

0 

O 

O 

0 

no 

CM 

CO 

-ft 

to 

UN 

ON 

to 

ft 

to 

UN 

no 

CM 

CO 

UN 

On 

VO 

VO 

UN 

ON 

UN 

-ft 


•A 



r\ 




C\ 


•A 


1 - 1 



CM 




1 - 1 


UN 

O 

O 

0 

O 

O 

O 

0 

O 

O 

O 

O 

VO 

no 

ON 

O 

OO 

ON 

0 

CO 

to 

O 

UN 

1 — t 

to- 

CM 

UN 

VO 

to- 

ON 

UN 

CM 

UN 

-d- 


«A 

*A 

i> 

«A 

C\ 

«A 

«A 

«A 


«A 

1 —1 

CM 

on 

1-1 

CO 

1-1 

1 - 1 

' 1 - 1 

UN 

1 - 1 

UN 











1 — t 

ON 

ON 

VO 

CM 

VO 

no 

-ft 

CM 

ON 

O 

UN 

O 

ON 

UN 

to¬ 

OO 

1—1 

CM 

no 

VO 

ON 

ON 

OO 

1 —1 

to- 

co- 

O 

O 

O 

ON 

ON 

to 

O 

*\ 

#A 

*A 


«A 

«A 

#A 


#A 


«A 

CM 

CM 

1-1 


O- 

1-1 

1-1 


CM 


O 





-P 







>3 







m 







p 







cd 


ft 





•rH 







ft 


-P 





d 




d 



CO 

rCj 

cd 





•r ~1 




• r - 1 


1 

1 

-P 

g 



2 

>3 

d 




ra 


1>3 

-p 

cri 

cd 



P 

P 

EH 




cd 


0) 

-p 

g 

1 —1 

1—1 


•rH 

•H 


1—1 



ft 

d 

1 1 d 

0 

a5 


cd 

d 

d 

d 

ft 

cd 



ft 

0) 

1 —1 CD 

0 

1 —1 


-P 

CD 

•rH 

•H 

d 

P 



d 

> 

cd > 

CO 


<p 

O 

t> 

d 

d 

O 

O 

d 


CO 

•H 

t> ft 

1 


0 

P 

•1—1 

EH 

EH 

ft 

P 

CD 



K 

1 « 

d 

CD 


ft 

K 




ft 

!> 


d 


CD 

0 

1-1 

d) 

d 


d 

d 

ft 

d 

•1—1 


0 

ft 

-P -P 

B 


p 

CO 

2 

CD 

CD 

P 

CO 

K 



-P 

-P W 

ft 


d 


p 

Ph 

d 

d 




d 

eg 

d 0 

cd 

•H 

0 


•H 

SP 

0 

0 


ft 

1—1 

•rH 

S 

PQ PI 

CO 

S 

2 


d 

ft 

ft 

CO 


P 

cd 

C/3 

cd 






•H 





•l~1 

p 

cti 

1 —1 






d 





B 

0 

PQ 

ft 






EH 





CO 

EH 


69 









































Annual Sediment Rate Per Mile of Stream 
In The Northern Basins 


; 


p 

cd 



-p 

CD 

CD 

P>H 

I 

CD 

P 

O 

< 


CD 

-P 

cd 

PC 

-P 

Pi 


•i—I 

t3 

CD 

co 


r ~1 

(D 

CO 

M 

cd 

cd 


P 

P 

CD 

B 

t> 

co 

< 




-P 


CM 


O 

CT\ 

ON 

o 

OO 

c- 

VO 

LTV 

OO 

CM 

t—1 

o 

i—i 

1—1 

1—1 

i—1 

i—i 

i—1 

i—i 

i—1 

o 

o 

o 

• 

o 

o 

o 

o 

o 

o 

o 


Lf\ 


UO 


C- t- 

• • 

i —I i—1 


LO 

t- 

i—1 


CO 

P 

CD 

Tj 

P 

O 

£ 

cd 

CD 

P 

-P 

co 






o 

o 


o 


o 


xi 

1 

i 

i 

LT\ 

UO 

• 

o 

1 

o 

i 

-P 

CO 




« 

I-1 

i — 1 


CM 


CM 




o 

OO 


o 


o 

OO 

o 


-P 

1 

o 

VO 

1 

t~- 

i 

o 

OO 

LTV 

1 

r- 


• 

1 — 1 

o 


o 


CM 

1 — 1 

1 — l 




LTV 

to- 


OO 

i — i 

PO 

o 

CO 

o 

-p 

P 

t- 

vo 


vo 

t- 

OO 

pf 

£- 

o 

VO 

Eh 

o 

o 


® 

o 

o 

o 

1 — 1 

o 

1—1 



o 

o 

t- 

00 

pt 

CM 

o 

00 

Pt 

-p 

P 

LCN 

VO 

vo 

Pt 

VO 

Pt" 

Pt 

Pt 

r—1 

LCO 

EH 

• 

o 

o 

o 

o 

o 

• 

o 

o 

o 

1 — 1 


CO 

I—1 

vo 

o 

o\ 

OO 

CM 

c- 

CM 

CM 

-P 

O 

-3" 

LTV 

pt 

OO 

OO 

VO 

CM 

Pt 

Pt 

Pt 

o 

• 

o 

• 

o 

• 

o 

o 

o 

o 

o 

o 

o 

rO 


CTv 

o 

LTV 

ON 

CM 

ON 

ON 

to- 

pf 

P 

p 

O 

i—1 

i—1 

o 

CM 

1—1 

o 

i—1 

o 

CO 

EH 

o 

o 

o 

o 

o 

• 

o 

o 

o 

o 



LTV 

OO 

i—1 

LTV 

0O 

oc 

On 

to- 

00 

PI 

CM 

Tr 

o 

o 

o 

o 

i—1 

o 

o 

o 

o 

o 

o 

• 

o 

o 

• 

o 

o 

o 

o 

o 


o 

co 

i—i 

CO 

On 

O 

CM 

o 

VO 

LTV 

o 

o 

Pt 

o 

i—i 
i—i 

o 

vo 

o 

o 


On 

ON 

VO 

CM 

o 

ON 

LTV 

n- 

OO 

I — 1 

to- 

tr~- 

#n 

«\ 



CM 

CM 

cd 

-P 

co 

cd 

,P 

1 — 1 

xi 

+3 


CO 

rP! 

eg 

1 


-p 

£ 

f>> 

-P 

cri 

cd 

CD 

-P 

g 

1—1 

<-i P 

o 

cc5 

W 

i—1 CD 

V 

i—l 


cd t> 

CO 

« 

> *H 

1 


o 

PC 

Pi 

CD 


CD 

o 

r—1 

rP 

-P -P 

B 

Tj 

-P 

H- 3 CO 

H 

Ti 

B 

p O 

cd 

•p 

o 

PQ t-Q 

CO 

S 

S 


OO 

Pt 

CM' 

1—1 

CM 

0O 

o 

O 

CT\ 




1—1 

1-1 



-P 

•p 






p 



co 





*rH 



p 




>> 

P 



•p 



-p 

-p 

EH 



CO 



•H 

•r*l 




cd 

<D 

p 

Pi 

P 

Xi 

CD 


PQ 

W 

CD 

•H 

• i—1 

P 

hQ 



c6 

> 

p 

P 

o 

cd 

P 

P 

u 

•Hl 

EH 

EH 

pH 

P 

P 

o 

CD 

PC 




CD 

t> 


> 


p 

p 

Xi 

t> 

•r—1 


< 

>> 

CD 

CD 

-P 

< 

PC 

CD 


-p 

Ph 

£ 

P 



M 


•iH 

PM 

o 

o 


xc 

cd 


pi 


l-Q 

CO 


-p 

P 


• i—1 





•H 

CD 


p 





£ 

i> 


EH 





CO 

< 


70 



































area of unstable geologic formations and more streams per square mile. 
Some private lands in the basin have been tractor logged. 

The Lower and South Fork Subbasins of the Trinity Basin have higher 
sediment rates from streambanks than the Upper Trinity Subbasin. There 
is a 1+0- to 70-inch variation in rainfall, but the variation is somewhat 
uniform within each of the subbasins. Flatter gradient streams located 
in terrace material usually occur in the two lower subbasins, and 
probably account for this increase in sediment yield per square mile. 

The Smith Basin also has a higher sediment rate than the Klamath Basin. 
As in the Trinity Basin, unstable geologic formations cover a large 
portion of the Smith Basin. 

INFLUENCE OF MAN’S ACTIVITY 

Most streambank erosion is caused by natural geologic and hydrologic 
conditions, but some was directly influenced by man's activities. The 
magnitude of this influence was estimated by analyzing the field data 
and studying aerial photographs. Watershed areas above the sampled 
streambank reaches were examined on aerial photographs for evidence of 
activities such as logging, roadbuilding, and grazing. Field samples 
were divided into two groups -- those with evidence of man's activities 
and those without -- and the average sediment yield was determined for 
each group and stream order. The average sediment rates from the un¬ 
disturbed sample areas are assumed to be natural rates and, in all 
cases, are less than those associated with man's activities. The dif¬ 
ference between these rates is the estimated influence of man on stream- 
bank erosion. Only the 2nd, 3rd, and 4th orders were analyzed because 
watershed areas above the larger stream order samples all contained 
some form of man's activities, and natural sediment rates could not 
be determined. Within the scope of this study, there is no effective 
way to analyze the influence of man's activity on streambank erosion 
in the larger stream orders, but it is considered to be less than that 
in the smaller stream orders. 

The following tabulation presents the sediment yield from 2nd, 3rd, and 
4th order streambanks directly influenced by man's activity for each of 
the basins: 

Sediment Yield 

Total Sediment Directly Influenced By Man 


Yield From All Streams 
Basin (Acre-Feet/Year) 

From 2nd,3rd, & 4th Order 
(Acre-Feet/Year) 

Percent Of 
Total 

Klamath 

1,330 

310 

23 

Trinity 

1,240 

240 

19 

Smith 

290 

70 

24 

Rus sian 

900 

120 

13 

Mendocino 

Coastal 1,210 

280 

23 

Clear Lake 

110 

30 

27 

Total 

5,080 

1,050 

21 avg. 


71 











The table shows that at least 21 percent, or 1,050 acre-feet per year, 
of sediment yield from streambanks is directly influenced by man. 

In the Northern Basins, essentially all of this influence came from 
tractor logging operations and associated spur roads. In the Southern 
Basins, about 80 percent of the sediment yield from this influence came 
from tractor logging operations; the rest was from grazing and other 
activities, as indicated in the following tabulation: 

Sediment Yield Directly Influenced By Man 
(Acre-Feet/Year) 


Bas in 

Logging 

Grazing and 

Other Activities 

Total 

Russian 

84 

36 

120 

Mendocino Coastal 

240 

4 o 

280 

Clear Lake 

26 

4 

30 

Total 

350 

8 o 

430 


FUTURE SEDIMENT YIELD 

Unless an effective land treatment program is installed, the future 
sediment yield from streambanks is expected to continue at about the 
present rate of 5>080 acre-feet per year for the next 50 years. The 
present sediment yield for the 24-year study period is higher than the 
average for the last 50 years. One reason is that major storms, such 
as that of December 1964, leave most of the streambanks bare and sub¬ 
ject to heavy erosion for many years. The subsequent regrowth of veg¬ 
etation along the banks is sometimes retarded by the less intense storms. 


72 



















LAND TREATMENT PROGRAMS 


Land treatment programs are presented in two phases -- measures to 
remedy sediment yield problems and increase productivity and management 
guidelines to prevent future problems. Costs, methods and problems of 
implementation, and effects of each program are discussed. 


REMEDIAL AND PRODUCTION IMPROVEMENT PROGRAMS 


The programs described in this section are recommended for basinwide 
installation because they either reduce sediment yield or increase 
productivity of the land. In many cases, they do both. Several other 
measures were investigated and were considered inadequate to meet those 
criteria, at least within practical economic limits. For example, 
basinwide installation of remedial measures that would reduce sediment 
yield from landslides and streambanks are not recommended because their 
high cost makes them impractical for general use. However, some may 
be feasible in local areas where high values are involved. 

A simplified benefit-cost procedure was employed to determine the 
relative efficiency of the land treatment measures. The average annual 
land treatment costs were calculated for each range site after discount¬ 
ing for a 20-year installation period. The future annual increase in 
AUM's was calculated for each range site. The AUM's were multiplied 
by a value of $4 and discounted for lag in accrual. The benefits 
were then divided by the costs to determine the benefit-cost ratio. 

Those practices having a relatively low benefit-cost ratio were elim¬ 
inated from consideration. No attempt was made to evaluate other benefits 
such as fish and wildlife benefits in this study. The cumulative 
environmental effects of these programs are described in the main report. 

Total cost of the remedial and production improvement program is 
$90,109,000 over a 20-year installation period. Average annual main¬ 
tenance costs are predicted to be $5,112,000, about 90 percent of which 
is for road maintenance. 

PRIVATELY OWNED GRASSLAND 

Privately owned grasslands encompass about 1,592 square miles. Because 
of the differences (mainly in productivity and climate) between the 
Northern and Southern Basins, separate programs were developed for 
natural grasslands in these areas. A third program was formulated to 
reforest suitable areas of grassland that had originally been converted 
from timberland. The total cost of these three programs is nearly $l4 
million. 

Better grazing management will be essential to maintain the improved 
forage conditions and soil cover and to reduce sediment yield from all 
grazing lands regardless of erosion class or present condition. On¬ 
site investigations will be necessary to select the most effective 


73 











treatment for each area. Technical services should be provided to 
assist landowners in making these decisions for each specific area. 

Natural Grassland -- Southern Basins 


The program for privately owned natural grasslands in Southern Basins 
covers about 462 square miles. It will provide the necessary increase 
in ground cover density and organic litter for sediment reduction and 
forage improvement. 

Measures 

Natural grasslands were grouped into three erosion classes -- slight, 
moderate, and severe -- that are discussed in the section "Soils Data" 
in the, Addendum. Proposed treatment measures differ for each class. 

Slight Erosion Class 

This class comprises about 278 square miles of natural grassland and 
has slight sediment yields that average 80 acre-feet per year. On 
about 91 square miles, vegetal cover conditions are poor, and these 
areas should be reseeded and fertilized. Another 116 square miles have 
adequate natural seed and plants available, but should be fertilized to 
improve the composition and vigor of the stands. After good stands 
have been established in both areas, they should be fertilized about 
every third year to maintain maximum forage production. The remaining 
71 square miles in this class produce adequate forage. 

Moderate Erosion Class 

About 139 square miles of natural grassland are in this class, which 
has moderate sediment yields that average 119 acre-feet per year. 

This land has been heavily grazed, leaving the ground cover in poor 
condition. About 4 square miles should be reseeded and fertilized 
to improve cover. Followup fertilizing will be needed about every 
third year to maintain the improved grass forage. Because of steep 
slopes and low potential for improvement, remedial measures are not 
considered practical on the remaining 135 square miles of land in this 
class. 


Severe Erosion Class 

This class comprises about 45 square miles of natural grassland and 
has high sediment yields that average 106 acre-feet per year. Because 
the ground cover is badly depleted, all of the existing vegetation is 
needed for soil erosion protection. The entire 45 square miles should 
be fertilized to improve the ground cover and should be fenced to ex¬ 
clude livestock grazing. Seeding to grasses would be desirable, but 
steep slopes and gullies make it impractical. Without proper seedbed 
preparations, seeding would be ineffective. In some areas, planting 
of suitable trees and shrubs may be feasible to reduce erosion and 
heal gullies. In general, it is impractical to construct debris dams 
or mechnically repair damaged lands because of the ruggedness of the 
terrain and the high erodibility of newly disturbed areas. 

74 



Cost 


The table "Estimated Costs of the Private Natural Grassland Program in 
the Southern Basins" is presented on the following page. The total cost 
of installing the remedial measures is $5,404,000, averaging $ 292,000 
per year for the 20-year installation period. After the installation 
period, an annual cost of $254,000 would be required for maintenance. 

Natural Grassland -- Northern Basins 

The Northern Basins encompass 916 square miles of privately owned 
natural grasslands. The entire estimated 15 square miles of grassland 
in the Trinity Basin and about 175 square miles of grassland in the 
Klamath are expected to be converted to more intensive use during the next 
50 years. These areas need protection from erosion and improved manage¬ 
ment until conversion is accomplished. Treatment of these lands before 
conversion might avoid much disturbance during conversion. No appreci¬ 
able acreage of grassland exists in the Smith Basin. This program 
covers the remaining 726 square miles of natural grassland in the 
Klamath Basin. Soil erosion is only a minor problem on most of these 
grasslands, but it is significant in places. Treatment measures are 
mainly designed to improve grass forage. 

Measures 

Since treatment measures vary, depending on the condition of plants, 
natural grasslands in this area are divided into two groups -- range 
sites in poor condition and those in fair condition. Range sites in 
good condition are almost non-existent in this area. 

Range Sites in Poor Condition 

This group comprises about 622 square miles of rangeland that is pro¬ 
ducing less than 25 percent of its forage potential. The number of 
existing grass plants is insufficient in some areas to produce the 
necessary seed to improve the stand naturally. Brush cover should be 
removed by mechanical means where needed on about 193 square miles, 
and the area should be reseeded to perennial grasses and legumes on a 
suitable seedbed. About 348 miles of fencing would be needed to pro¬ 
tect these newly seeded areas. The remaining 429 square miles should 
not be seeded because they lie on steep slopes and rocky soils. An 
additional 274 miles of fence and 308 stockwater developments would 
make uniform distribution of grazing possible over the entire area, and 
proper livestock management would be essential to maintain good forage 
production. 

Range Sites in Fair Condition 

This group comprises about 104 square miles of natural grassland that is 
producing one-quarter to one-half of its potential. There is an ade¬ 
quate supply of natural perennial plants, but improved livestock manage¬ 
ment practices are needed to increase forage production. An estimated 
6 l miles of fence and 45 stockwater developments would allow better 


75 







Estimated Costs of the Private Natural Grassland Program 
in the Southern Basins 


Item 

Unit 

Quantity 

Total 

Cost 

($) 

Annual 

Maintenance. 

Cost 

($) 

Slight Erosion Class 
(207 square miles) 
Seeding 

Fertilization 

Subtotal 

Sq.Miles 
Sq.Miles 

91 

207 

90,000 

3,375,000 

4 , 365,000 

232,000 

232,000 

Moderate Erosion Class 
(4 square miles) 
Seeding 

Fertilization 

Subtotal 

Sq.Miles 
Sq. Miles 

4 

4 

51,000 

66,000 

117,000 

4,000 

4,000 

Severe Erosion Class 
(45 square miles) 
Fertilization 
Permanent Fencing 
Subtotal 

Sq.Miles 
Miles 

45 

100 

302,000 

200,000 

502,000 

8,000 

8,000 

Technical Services 
(462 square miles) 
Total 



420,000 

5,4o4,ooo 

10,000 

254,000 


y 


Annual maintenance cost after the 20-year installation period. 
During the 20-year installation period, annual maintenance costs 
will average one-half of this amount. 


76 



















Grassland that has sufficient vegetal cover to prevent ex¬ 
cessive erosion. This range site is in poor condition with 
a cover mainly of Medusa-head. scs photo a-ssae-z 



A range site that has been seeded to perennial grass. 

SCS PHOTO 3-5538-6 



A brush covered range site in fair condition. Mt. Shasta in 
the background. photo a-ssas-n 


77 








grazing management, and carefully controlled chemical spraying for 
brush control on about 54 square miles would allow grasses to grow more 
vigorously. About 5 square miles of meadow area should be reseeded to 
more desirable grasses; although these meadows could be improved by 
better grazing management, improvement would be faster with reseeding. 

Cost 

The table "Estimated Costs of the Private Natural Grassland Program in 
the Northern Basins" is on the following page. The total cost of 
installing the remedial measures is $5,105,000, averaging $ 275,900 per 
year for the 20-year installation period. After the installation 
period, an annual maintenance cost of $ 275,000 would be required. 

Converted Timberland 

Essentially all of the grassland converted from timberland occurs in 
the Russian and Mendocino Coastal Basins and comprises about 2l4 square 
miles, which is about 13 percent of the privately owned grassland. 
Treatment measures for these lands are designed to improve the vegetal 
cover, increase production, and reduce sediment yield. 

Measures 

Because of the difference in treatment measures for these lands, they 
are divided into three areas -- those that should be reforested, those 
that should remain in grass for grazing, and those that are so severely 
eroded that they must be permanently excluded from uses that cause 
further erosion. 

Area to be Reforested 

About 57 square miles of converted timberland are classified as high 
or very high quality sites for Douglas-fir forests. These lands should 
be reforested since timber soils usually are .strongly acid and have a 
relatively low fertility level for grasses.—/ On these lands, much 
effort is required to prevent regrowth of woody vegetation, and good 
quality timberland will yield greater returns over a long period of 
time.— These newly forested lands should be fenced for 3 or 4 years to 
exclude grazing. 


i/Robert A. Gardner and others, Wildland Soils and Associated Vegetation 
of Mendocino County, California , p. 19ff. (Sacramento: Resources 
Agency of California, Cooperative Soil-Vegetation Survey Project 1964). 

2 / 

Adon Poli and E.V. Roberts, Economics of the Utilization of Commercial 
Timberland on Livestock Ranches in Northwestern California , Miscel- 
laneous Paper No. 25, p. 36ff. (Berkeley, USDA Forest Service Cali¬ 
fornia Forest and Range Experiment Station, April 1958). 


78 










Estimated Costs of the Private Natural Grassland Program 
in the Northern Basins 


Annual 





Total 

Maintenance 




Cost 

Cost l/ 

Item 

Unit 

Quantity 

($) 

($) 

Range Sites in Poor Condition 




(622 square miles) 





Seeding (Brush control 





where needed) 

Sq.Miles 

193 

3 , 088,000 

174,000 

Fencing 

Miles 

622 

732,000 

45,000 

Stock Water Development 

Number 

308 

308,000 

15,000 

Subtotal 



4,128,000 

234,000 

Range Sites in Fair Condition 




(104 square miles) 





Brush Control (Spraying) 

Sq.Miles 

54 

173,000 

i4,ooo 

Seeding 

Sq.Miles 

5 

80,000 

5,000 

Fencing 

Miles 

6 l 

79,000 

5,000 

Stock Water Development 

Number 

45 

45 , 000 

2,000 

Subtotal 



377,000 

26,000 

Technical Services 





(726 square miles) 



600,000 

15,000 

Total 



5 , 105,000 

275,000 


Annual maintenance cost after the 20-year installation period. During 
the 20-year installation period, annual maintenance costs will average 
one-half of this amount. 


79 


















Area to Remain in Grass 


About ih'f square miles of converted timberland is classified as medium 
to low quality for Douglas-fir forests. These lands are not considered 
feasible for reforestation and probably should remain in grass cover. 
About 10 square miles are suitable for good grass forage production and 
should be seeded and fertilized, with followup fertilization every third 
year to assure maximum forage production. The remaining 137 square miles 
in this group has little potential for forage improvement, and no addi¬ 
tional treatment measures are recommended. 

Severely Eroded Area 

This area contains about 10 square miles and has ground cover that is 
badly depleted. These lands should be fertilized to improve the 
vegetal cover for protection against erosion and should be fenced to 
exclude livestock grazing. In some areas, planting of trees and shrubs 
may be practical to reduce erosion and heal gullies. 

Cost 

The table "Estimated Costs of the Private Converted Timberland Program 
in the Southern Basins" is on the following page. The total cost of 
installing the remedial measures is $ 3 , 150 , 000 , averaging $170,200 
per year for the 20-year installation period. After the installation 
period, an annual cost of $20,000 would be required for maintenance. 

Effects of the Program 


Sediment Yield 

The land treatment programs for privately owned grassland would reduce 
the sediment yield by about 300 acre-feet per year in the Southern 
Basins. The program for privately owned grassland in the Northern 
Basins would improve forage production and maintain a good surface 
cover, but would have only a minor effect on sediment yield. The 
following table presents the estimated area and sediment yield for 
privately owned grasslands in the Southern Basins, with and without 
the installation of the land treatment program. 

Production 

The private grassland program would increase the future forage 
production by about 433,000 animal-unit-months, which represents an 
increase of 250 percent over the expected production without the 
program. This increase is based on the assumptions of constant price 
levels and the installation of the complete land treatment program. 
Since reforestation areas will be fenced to exclude livestock grazing, 
forage production in these areas will be zero. The table "Grass 
Forage Production on Privately Owned Grassland" gives a breakdown 
of the production by classes or areas of land. 


80 




Estimated Costs of the Private Converted Timberland Program 

in the Southern Basins 


Item 

Unit 

Quantity 

Total 

Cost 

($) 

Annual 

Maintenance- 

Cost 

($) 

Reforestation Area 
(57 square miles) 
Tree Planting 
Temporary Fencing 
Subtotal 

Sq. Miles 
Miles 

57 

23 

2,554,000 

30,000 

2,584,000 

2,000 

2,000 

Grassland Area 

(10 square miles) 
Seeding 
Fertilization 
Subtotal 

Sq.Miles 
Sq.Miles 

10 

10 

109,000 

160,000 

269,000 

11,000 

11,000 

Severely Eroded Area 
(10 square miles) 
Fertilization 
Permanent Fencing 
Subtotal 

Sq.Miles 
Miles 

10 

25 

67,000 

50,000 

117,000 

2,000 

2,000 

Technical Services 
(214 square miles) 
Total 



180,000 

3,150,000 

5,000 

20,000 


U 


Annual maintenance cost after the 20-year installation period. 
During the 20-year installation period, annual maintenance costs 
will average one-half of this amount. 


81 






















£ 


Td 

cd 


m w 
w p 
cd • |—1 
P W 
O cd 

m 

Td 

CD a 
S P 
t: CD 
O ,P 
-P 
r^ P 


i—I O 

0) CO 
-p 

cd a) 


> dd 


f^H P 


•I—I 


CD 

& 

-P 

Ch 

O 

w 

-p 

o 

CL) 

pH 

pH 

Pd 


-P 





CD cd 


S QJ 

w 

•i—i |>H 

CD 

Td 

p 

0) Td -P 

P 

co iH a) 

w 

CL) CD 

cd 

1—1 'H pH 

jd 

cd >H I 

s 

P CD 


P fn 

<—1 

P O 

td 

< 

Td 


a) 


£q 


a> 


K 


-p 

CO 


CD 

o 

rH 

Pd 

Cd -H 

-p 

CD S 

•i—1 

fn • 

is 

< Cd 1 


CO 


O 

LTN 


o 

0O 


o 

ON 

I—I 


NO 

CVJ 

CM 


O 

co 


vo 

LTN 


O 

[O 

PO 


CM 

VO 

Pt 


O O Ol o o 
on co oo| on vo 

rH LTN 


LTN 

VO 

CO 


vo 

LTN 

CM 

CO 

1—1 

E— 


1-1 


C\J 

VO 



-p ^ 


Sd fn 


(D cd 


£ CD 


•i — i |>h 

C/) 

Td O 

CD 

CD Td -P 

U 

CO rH a) 

0 

CD CD 

cn 

rH vH pH 

ai 

cd >H 1 

0) 

P CD 

s 

P fn 


P CJ 

1—1 

< < 

cd 


•i—i 



o 

co 


o o o 
vo pf oo 


fn O Ol o o 

Eh t— rH| CO vo 

CM 


Td 

0) 

e 

( 1 ) 

Ph 

.P 

-p 

•I—I 

ts 


cd 

W 

CD 

rH 

*(H 

co 

ON 

Lf\ 

CM 

IN- 

o- 

o 


VO 

CD 

s 

t- 

CO 


VO 

LTN 


1—1 

1 —1 

IN- 

P 

< 

a 1 

co 

CM 

rH 


pf 


1—1 


C\J 

VO 


Td 

a 








cd 



Td 









■—l 



CD 




£ 





P 

P 


Td 




cd 





CD 

o 


o 




i—1 




i—1 

rQ 

•c—i 


p 

i—1 

1—l 

CO 

cn 




cd 

s 

-P 


Pd 

cd 

cd 

CO 

cn 




-P 

•1-1 

cd 

T3 


-P 

-P 

cd 

cd 


CD 


o 

EH 

+3 

£ 

i» 

o 

o 

i—1 

£ 


-P 


-p 


w 

cd 

i—1 

-p 

EH 

o 

O 

-p 

cd 

CD 

o 

Td 

CD 

i—1 

CD 

,Q 




dd 

p 

P 

p 

CD 

P 

cn 

P 

p 


£ 

•—1 

bO 

CD 

CD 

CO 

-p 

O 

cn 

CD 

CO 


o 

cd 

•(—1 

Td 

> 


p 

ph 

cd 

> 



•1—1 

£ 

l—1 

o 

CD 


CD 

CD 

£ ; 

CD 



w 

3 

co 

S 

CO 


> 



CO 



o 

-p 





p 






p 

cd 





o 






Pd 

s 





O 







82 























Grass Forage Production on Privately Owned Grassland 
(Animal-Unit-Months) 


Class or Area 

Present 

Condition 

Future 

Without 

Program 

Future 

With 

Program 

Natural Grassland 
(Southern Basins) 




Slight 

117,000 

64,000 

298,000 

Moderate 

60,000 

104,000 

62,000 

Q V 

Severe— 7 

0 

0 

0 

Subtotal 

177,000 

168,000 

360,000 

Natural Grassland 
(Northern Basins) 




Range Sites in Poor 
Condition 

73,000 

45,000 

248,000 

Range Sites in Fair 
Condition 

43,000 

30,000 

59,000 

Subtotal 

116,000 

75,000 

307,000 

Converted Timberland 




Reforestation 

13,000 

11,000 

oi/ 

Grassland 

4i,ooo 

36,000 

56,000 

Severely Eroded-^ 

0 

0 

0 

Subtotal 

54,000 

47,000 

56,000 

Total 

347,000 

290,000 

723,000 


i/Current forage production is essentially zero, and the recommended 
treatment for these lands is to exclude grazing. 

^Afoder the recommended program, grazing will be excluded from 
reforestation areas. 


83 

















Timber production from reforestation of converted timberland would 
increase timber production by 8 million cubic feet per year. The 
optimum harvest period would be 60 years for saw logs, but two thin¬ 
ning cycles would be required during this period. Trees removed by 
thinning could be used for pulpwood, Christmas trees, or fuelwood. 

PUBLICLY OWNED GRASSLAND 

There are about 9^3 square miles of public grass and herb covered land. 
Of this, about 246 square miles are capable of producing timber of 
commercial quality and volume. However, only 40 square miles are 
considered to be highly productive and economically feasible to reforest 
under present price structures and interest rates. The other 206 
square miles, although not now feasible to reforest, should be left 
in their present condition. They can be used for grazing but will 
no doubt reforest naturally at a very slow rate. If prices rise as 
demand for lumber increases, it may become economically feasible and 
desirable to intensify management for timber production on some of 
these areas. 

About 701 square miles of the grass and herb covered lands have natural 
grassland soils and are capable of producing at least 0.3 animal-unit - 
months of forage per acre per year. This land is well suited to 
grazing, and it is recommended that such use be continued. Another l6 
square miles are judged to be suitable for open space uses, such as 
dispersed recreation and wildlife habitat, but intensive uses should 
not be permitted. 

Measures 


The reforestation program consists of mechanically removing existing 
grass and herbaceous vegetation and planting trees. Weeding is essential 
during the first five years to free young trees from competition. On 
gentle slopes, weeding can be accomplished by machine, while on steeper 
slopes, a combination of hand weeding and spot applications of herbicides 
may be used. Where feasible, carefully controlled aerial spraying 
would reduce costs 30 to 60 percent; however, since the effects of 
herbicides upon the environment are not fully known, and such a program 
requires extreme care and a detailed study of the long-range ecological 
effects, it was not included. 

The 206 square miles of forest soils not now feasible to reforest and 
the 701 square miles recommended to remain in grass should be managed 
for grazing. The public agencies that have jurisdiction over these 
lands generally have programs that are designed to achieve proper 
management and development of the grazing resource. Therefore, no 
further program recommendations are made here. 

The 16 square miles that are suitable only for open space management 
may require some fencing, although it is probable that proper manage¬ 
ment will achieve the desired results. 


84 



Cost 


The following tabulation shows a breakdown of the total cost for the 
)|0-square-mi In area to be reforested over a 20-year period. 


Item 

Cost Per Acre ($) 

Total Cost ($) 

Site Preparation 

20 

512,000 

Tree Planting 

20 

512,000 

Weeding 

30 

768,000 

Total 

70 

1,792,000 


After the initial installation is accomplished, the only additional 
costs would be for general land management and administration. 

Effects of the Program 


Sediment Yield 

Sediment yield would not be appreciably affected by this program. 
Production 

The program, when fully installed, would produce about 5 million cubic 
feet of wood annually based on the maximum average net growth. About 
20 percent of this volume would result from thinning that would start 
v/hen the trees are between 20 and 30 years old. The feasibility of 
this program is based upon thinnings and final harvest of timber 
products, although Christmas trees may be harvested, enhancing the 
benefits. Approximately 7,600 AUM’s of annual forage production will 
be lost as a result of the program. 

BRUSHLAND 

About 2,666 square miles of land, approximately half of which is 
privately owned, is presently covered with brush and chaparral, includ¬ 
ing about 1,366 square miles that is suitable for producing commercial 
timber. Only 139 square miles is considered productive enough to make 
a reforestation program feasible under the present price and interest 
rate structure. The recommended program covers only that acreage. 

Another 277 square miles have been recently logged and will probably 
reforest naturally in time. Therefore, no reforestation program is 
proposed for those lands; it is recommended, however, that they be 
managed for timber production. The remaining 950 square miles, although 
suitable for timber production, are not considered potentially productive 
enough to support a reforestation program with the present price and 
interest rate situation. A change in either of these or a less expen¬ 
sive reforestation procedure could result in making many more acres 
feasible for reforestation. These 950 square miles and the 1,300 square 
miles of brushland that is incapable of producing timber crops should 


85 












bo left in their present condition, in which they will continue to 
provide wildlife habitat, watershed protection values, dispersed 
recreation, and a small amount of grazing. In the future, economic 
conditions may make it feasible to convert some of these lands to grass. 

Measures 


Brush should be removed by mechanical means and, if possible, chipped and 
spread over the area. After the trees are planted, at least one weeding 
is essential during the first five years to keep the young trees free 
from competition. Where conditions are suitable, weeding can be 
accomplished mechanically, but a combination of hand weeding and spot 
applications or herbicides may be necessary in some cases. Weeding 
must be done carefully to avoid erosion. About 75 percent of the 
program would take place on private land where technical services would 
be needed for assistance to landowners. 

The use of herbicides for brush removal would lower costs by 30 to 60 
percent and would make the reforestation of considerably more land 
feasible; however, because of the uncertainty regarding herbicides, 
their use was not included. 

Cost 


The following tabulation shows a breakdown of the total program costs 
over a 20-year period for the 139 square mile area to be treated. 

On privately owned land, the recommended program would probably require 
a cost-sharing arrangement between the government and the landowner. 


Estimated Cost Of 
Reforestation Program 
On Brush Covered Lands 


Item 

Cost Per Acre ($) 

Total Cost ($) 

Site Preparation 

100 

8,896,000 

Tree Planting 

20 

1 , 779,000 

Weeding 

15 

1 , 334,000 

Technical Services 

- 

300,000 

Total 

135 

12,309,000 


Effects of the Program 

The program, when fully installed, would produce about 19 million 
cubic feet of wood annually based on a high average net growth. About 
20 percent of this volume would result from thinnings that would start 
when the trees are between 20 and 30 years old. The feasibility of this 


86 










program is based upon thinnings and final harvest of timber products, 
but Christmas tree harvests nay enhance the benefits. Sediment yield 
would be reduced by about 30 acre-feet per year after the program is 
installed. 


ROADS 


There are approximately 14,500 miles of roads in the study area, respon¬ 
sibility for which is distributed as follows: 

Federal State County Private Total (Miles) 

8,078 1,226 4,783 368 14,455 

Of the roads maintained by the federal government, 7,925 miles are 
under the direct care of the Forest Service, and the proposed program 
covers only these roads. The following tabulation summarizes the mile¬ 
age of these roads by status: 


Length 


Description of Road (Miles) 


Paved Permanent 

Near Stream!/ 540 

Away From Stream 836 

Subtotal 1,376 


Unpaved Permanent 

Near Stream!/ l, 04 l 

Away From Stream 3 , 3 l 8 

Subtotal 4,359 


Unpaved Temporary!/ 


2,190 


Total 


7,925 


1/ 


"Near stream" 
a stream. 


means that the road centerline is within 100 feet of 


2 / 


Proximity to stream was not ascertained. 


Measures and Costs 


The table on the next page presents types of measures to be installed 
over a 20 -year period and the estimated costs for installation. The 
1,376 miles of permanent paved roads are not included in the program 
because sediment yield from these is low. Some unpaved permanent roads 
are little used and should be closed to all traffic, while some unpaved 
temporary roads receive considerable use and should be upgraded into the 
permanent status. 


87 



















Estimated Measures and Costs for National 
Forest Roads in the Northern Basins 





Annual 



Construction 

Maintenance 


Length 

Cost 

Cost 

Measure 

(Miles) 

($1,000) 

($1,000) 


Unpaved Permanent Roads 
Near Streams 


Paving 

300 

22,255 

1,688 

Improved Drainage 

550 

7,755 

433 

Relocation 

86 

2,580 

196 

Road Closure 

105 

21 

0 

Subtotal 

i,o4i 

32,611 

.2,317 

Away From Streams 

Paving 

166 

12,314 

934 

Outsloping 

2,820 

564 

45 

Road Closure 

332 

66 

0 

Subtotal 

3,318 

12,944 

979 

Unpaved Temporary Roads 

Paving 

219 

16,246 

1,232 

Outs loping 

1,533 

46o 

35 

Road Closure 

438 

88 

0 

Subtotal 

2,190 

16,794 

1,267 

Total 

6,549 

62,349 

4,563 
























Road paving consists of all types, such as asphalt, chip seal, and 
gravel, and includes the necessary drainage facilities. Drainage 
improvement is considered primarily for unpaved roads and includes 
ins loping of road surfaces and installing of paved gutters, culverts, 
energy dissipaters, crossdrains, concrete fords, and bridges. Road 
relocation is recommended on some reaches in unstable areas where 
maintenance problems are extensive. Road closure costs include instal¬ 
lation of barriers to stop traffic, removal of temporary bridges and 
culverts, installation of water barriers on road surfaces, outsloping, 
and seeding. Outsloping consists of grading unpaved roads so that 
they slope toward the downhill side and removing berms along the outside 
edges. 

Effects of the Program 


The road program is expected to reduce sediment yield on the area treated 
by about 75 percent, a reduction of about 480 acre-feet per year, or 
55 percent of the total volume of sediment from all roads. This 
program will result in a better road system that will provide more 
dependable year-round service to the public. 


MANAGEMENT GUIDELINES 


The following management guidelines are recommended to improve exist¬ 
ing situations and to prevent future problems. In some cases, they 
must be used in conjunction with remedial measures to achieve full 
rehabilitation of deteriorated sites. However, proper land management, 
by itself, usually has beneficial effects and can often be practiced 
without great cost to the landowners. Stabilization of the local 
economy and greater long-range returns to the landowner will usually 
result. 

SHEET AND GULLY EROSION 
Logging Guidelines 

1 . Logging operations should be planned well in advance, as is 
now done by the U.S. Forest Service, the California Division 
of Forestry, and large timber companies with forestry staffs. 
Owners of small timber tracts should obtain the assistance of 
foresters to arrive at the best plan for specific areas. 

2 . A system is needed for judging the potential soil erosion from 
lands where timber is to be harvested. An example of this 
type of system is the Erosion Hazard Rating System used by 
the Forest Service, in which weighted values are assigned to 
the individual characteristics of soil, slope, climate, and 
cover. The result is a numerical rating that indicates erosion 
hazard and the methods to be used when harvesting timber for 
each particular hazard area. It also indicates precautions that 
should be taken during logging and provides a guide to the type 
of postlogging treatment needed. 

89 










3 - Logging systems that minimize soil distrubance should be 
used. Cable logging or skyline systems are preferred for 
erosion control and are the only methods recommended for areas 
of high erosion hazard. Tractor logging is acceptable in 
areas of low erosion hazard. Where it is used, the number of 
skid trails should be minimized, and they should be constructed 
as nearly parallel to the contour as possible and provided 
with crossdrains after use. Long, continuous downslope skid 
trails should be avoided because they tend to channel the 
runoff and form gullies. 

4. Timber harvest should be deferred on extremely unstable soils 
where logging by present methods is likely to cause landslides. 
New methods, which are now being developed, will probably make 
it feasible to harvest such timber in the future. 

5 . Landings, roads, and skid trails should be located away from 
creekbeds or washes. Landings should be located on benches 
away from channels, and stream crossings should be avoided 
wherever possible. 

6. Steep slopes or shallow soil areas should not be logged where 
sediment will enter directly into streams. 

7- Temporary bridges or culverts should be installed at all 
watercourses to be crossed by trucks and tractors. During 
winter shutdown or immediately after logging is completed 
on a given area, the culverts and all fill material should 
be removed with a minimum of disturbance to the stream 
channel. 

8. Crossdrains (also referred to as waterbars, water breaks, or 
dips) should be constructed in all temporary roads and skid 
trails immediately after logging is completed on a given area 
and should be maintained as necessary. They should completely 
cross the course's width, have proper outlets, and be deep 
enough to withstand abuse, including travel over them by 
tractors or 4-wheel-drive equipment. Recommended spacing 
for crossdrains on national forest land is determined by the 
Erosion Hazard Rating. Where the Erosion Hazard Rating is not 
used, the following spacings are recommended as a guide: 


Percent 

Gradient 


Spacing Between Crossdrains(Feet) 


Over 40 


1 - 3 
4 - 8 
9-13 
14-22 
23-40 


250 

150 

100 

70 

4o 

25 


90 






Private logging area that has not been reseeded. - Roads and 
skid trails also were not properly eared for. =cs photo 3-5736-3 



Timber harvested in clear cut blocks. High lead system of 
logging was used to remove timber on Six Rivers Rational 
Forest. Cut blocks are shaped to fit contours. 


91 








The above spacings are to be measured on the slope. The water 
should be dissipated onto stable areas well protected by rocky 
ground, slash, or vegetal cover. Crossdrains should be 
located to promptly intercept runoff from lateral skid trails 
or other features that may concentrate runoff. 

As an alternative to crossdrain installation, all temporary 
roads could be outsloped 3 percent after logging is completed. 

9 - Immediately after logging is completed, and cross drains are 
installed, landings, skid trails, and spur roads should be 
seeded or planted with appropriate species, depending upon 
the erosion hazard. 

10 . In all areas where an inadequate seed source remains after 
logging, tree species should be seeded or planted to encourage 
immediate and complete reforestation. 

11 . Standards that minimize the length and width of entry roads 
into logging areas should be set and followed. 

12 . Gradients of logging roads should not exceed 10 percent. 

13 . Where soil disturbance is unavoidable, it should be confined 
to the contour as much as possible. Practices that lead to 
downhill convergence of skid trails and that concentrate 
runoff volumes should be avoided. 

14 . Soil disturbance within streamside zones (within 50 feet of 
a stream) should be restricted to that necessary for removal 
of insect or disease infested and decadent trees. Cable 
lift systems of logging are preferable, and use of ground 
disturbing, heavy equipment for tree removal should generally 
be excluded. When logging near streams, trees should be 
felled uphill away from channels, and slash debris should be 
kept out of watercourses. Any debris inadvertently deposited 
in channels should be removed immediately, with the least 
possible disturbance to streambeds and streambanks. 

15 - Prescribed burning should be minimized because it destroys 
both litter accumulations and plant canopy vital to soil 
protection and also creates large volumes of air pollutants. 
Slash or other unwanted plant materials should either be 
chipped and spread as protective cover or marketed for fiber. 

16. In areas devastated by wildfire, loss of litter and vegetal 
canopy exposes the soil to erosive forces. Salvage of 
merchantable timber should be permitted only where little 
further disturbance to the surface soils results. 

17 . Restrict the size, shape, and location of clear-cut blocks. 

The cut blocks should probably be limited in size to about 20 
acres and should conform to the lines of the terrain. 


92 








adjacent hillsides should have at least pole-sized stands. 

Cut blocks can extend across ridge tops, but not across channel 
ways. Roads should not be allowed within the bounds of a cut 
block, except along ridge lines. 



Converted timberland that is seventy eroded. Hardwoods have 
started to take over the area. , scs photo 3-5736-6 

Grazing Guidelines 

1 . Management plans that consider differences in forage, cover, 
topography, and other physiographic features should be for¬ 
mulated for all grazing areas. These should specify kind and 
number of livestock, system of grazing, length of season, 
improvement potentials, and other details pertinent to full 
utilization of the range consistent with adequate protection 
of the soils. 

2 . Stocking rates should be adjusted yearly to a level that will 
maintain the best possible vegetal cover for soil protection 
and grazing. The grazing season should be adjusted to avoid 
excessive damage to soils and vegetal cover that occurs when 
grazing takes place on wet soils. 

3 . In the Northern Basin, systems that defer grazing during 

the growing season at least every third year are recommended. 
This will enable the perennial grasses, desirable forbs, and 
brush species to replenish the plant food reserves and should 
result in healthier plants, more vigorous growth, more total 
forage, and greater amounts of viable seed. 


93 






4 . To avoid cover deterioration in small areas, livestock use 
should be distributed evenly over large areas. Good distri¬ 
bution can be aided by use of measures such as properly 
located stockwater facilities, fences, and salt licks. 

5 - Grazing should be excluded on land in the severe erosion class 
because all the vegetal cover is needed for protection of the 
soil. After the land has healed, extreme caution should be 
used in further grazing. Land in this class was found mostly 
in the Southern Basins. 

6 . Conversion of cutover timberland to grass should be limited 
to soils suitable for forage production. Such conversions 
require careful planning and sensible range management to 
prevent sediment and erosion damage to the land. 

7 . On land in the slight erosion class, livestock numbers should 
be reduced slightly or the season of use should be shortened. 
Seed is plentiful and ground cover is generally adequate, 

but composition and vigor of stands should be improved through 
lighter use. In the long run, this will protect the soil and 
increase economic returns. 

8. On land in the moderate erosion class, strong steps should 

be taken to bring livestock numbers into balance with the for¬ 
age supply. These lands are frequently overstocked, and the 
reduction of livestock will increase forage and provide 
greater protection for the soil resource. 

Deer Guidelines 


1 . Deer populations should be kept to a level commensurate with 
the carrying capacity of the wildlife habitat. This will 
maintain a healthier herd, protect the soil resource, and 
probably sustain a greater animal harvest. 

2 . Deer hunting effort should be spread more evenly to better 
utilize and manage the resource. Much of the private land, 
especially in the Southern Basins, is closed to public 
hunting, and although most of it is hunted to some extent 
by private clubs or friends of the landowners, this tends to 
concentrate hunters on national forest and other public lands. 

3 - Legislation should be provided and game management programs 
adjusted and coordinated to encourage private landowners and 
hunters to harvest deer under realistic management plans. 

These plans would enable them to remove deer of both sexes, 
to stimulate more efficient management of deer on private land, 
to improve deer habitat, and to realize reasonable monetary 
returns. 

On some cattle and sheep ranges, competition for feed between 
domestic livestock and deer has a detrimental effect upon the 

94 


4 . 





land. In these cases, until a sound deer management program 
is adopted, numbers of domestic livestock must be reduced to 
achieve a balance between grazing use and available forage. 

Wildfire Guidelines 


The following guidelines are designed mainly to recognize and plan for 
the impacts that are anticipated as the basins become developed: 

1 . Coordination between fire control, planning, fire prevention 
efforts, and pre-attack construction must continue and 

should be-intensified by cooperating fire suppression agencies as 
watersheds are subjected to more intensive use and increased 
■valuation. 

2 . Fire control and burned area rehabilitation practices that 
afford maximum protection to soil resources should be employ¬ 
ed. Regardless of the level of fire protection, fires will 
occasionally occur. To minimize soil damage and to rehabil¬ 
itate these areas as quickly as possible, the following should 
be considered: 

a. Expediency often dictates fire fighting tactics that 
disturb large areas of soil. The firefighting team should 
consider the resource values involved and choose the tactics 
that are least likely to cause soil erosion. The instal¬ 
lation of erosion control measures on all areas disburbed 
by fire fighting activities, presently standard practice 
with the Forest Service and California Division of Forestry, 
should be continued and improved wherever possible. 

b. Salvage logging or any other activity within the burned 
area should be undertaken with the guidance of the 
Erosion Hazard Rating System or similar systems. In many 
cases, the potential financial gain from these activities 
may not be worth the risks of increased erosion and loss 
of future productivity. 

c. The area should be seeded promptly to restore vegetal 
cover, and other emergency measures should be used to 
provide initial protection to the soil. Specialists 
should be consulted to formulate the best total rehabil¬ 
itation plan to eventually restore full productivity to 
all lands within the burned area. 

3 . Fuel breaks should have sufficient crossdrains for water 
dispersion, as described under item 8 of the "Logging Guide¬ 
lines" section in this chapter. These should be annually 
inspected for maintenance needs. 

Type Conversion Guidelines 


1 . The decision to type convert should hinge not only upon the 
production potential of the soils present, but upon the 


95 








inherent soil erodibility and steepness of terrain. Where 
conversion is desired on the more erodible soils and steep 
slopes, those practices that create the least soil disturbance 
or tend to disperse rather than concentrate expected runoff 
should be employed. A few examples are contour ripping, 
brush crushing, and the limited application of herbicides. 

2 . Detailed studies should be made to assure that the conversion 
will effectively meet the proposed objectives and that the 
economic returns will be satisfactory. For example, sites 

on timber soils should not normally be converted to grass and 
vice versa. Such conversions are generally ineffective, 
expensive to maintain, and do not usually result in high 
financial returns. 

3 . A combination of mechanical clearing or crushing and control 
burning should be given preference over the use of fire alone. 
However, controlled burns may be the only practical method 
for initial brush removal, especially in dense fields with 
heavy cover. Herbicides have proven very effective in both 
initial clearing and maintenance of conversions, but their 
effects upon the environment are questionable so they should 
be used carefully. 

4 . A specific seeding and fertilization prescription for each area 
to be converted to grass should be obtained from range manage¬ 
ment and soils specialists. 

5 - For conversions to grass, livestock grazing should be restricted 
and sometimes excluded until the grass cover is established and 
the seedlings have attained sufficient vigor to sustain them¬ 
selves. Grass cover and plant vigor should be maintained at 
a satisfactory level through proper grazing management. For 
conversions to timber, livestock grazing should be excluded 
entirely. 

6 . If control burning is done to help prevent escape of fire, 
burns should be kept relatively small, probably 200 acres 
or less, depending upon terrain and vegetal conditions. 

Burns should be well planned to take advantage of weather 
conditions that will allow a successful conversion, to assure 
full control at all times, and to provide for adequate post¬ 
fire treatment. 

Recreation Guidelines 


1 . Guidelines for road design, construction, and maintenance 
are presented in the "Road Guidelines" section of this 
chapter, and these should be followed during the installation 
of recreation roads. However, special care is needed because 
recreation roads are often built along streams and reservoirs, 
and road density is usually high. The construction of vista 
points or observation sites where large fills are usually 


96 





required, often on steep slopes, present especially critical 
erosion control problems. 

2 . Recreation, development sites along streambanks and lakeshores - 
such as beaches, campgrounds, picnic areas, and boat launch 
facilities -- should be carefully selected, designed, developed 
and operated to minimize streambank erosion. Locations that 
are particularly susceptible to damage, such as the outside 
curves of streams, flood plains, and areas with unstable soils 
should be avoided for development. Recreation development 
should be guided by professional recreation planners and 

designers. 

3 . Foot and horse trails should be located, constructed, and 
maintained so as to keep soil loss to a minimum; adequate 
drainage is the most important consideration. Barriers should 
be used to restrict vehicles to established roadway or park¬ 
ing surfaces, and foot travel should be confined to desired 
routes to reduce destruction of vegetal cover by trampling and 
to minimize soil compaction and erosion. To avoid permanent 
damage, trails and unsurfaced roads should be closed to use 
during wet seasons. Trails and roads that must be used during 
wet weather should be paved and drained. Camp and picnic 
sites and other areas where people congregate should be closed 
when use exceeds that which the soil can withstand. 

Cropland Guidelines 


1 . On-site investigations and detailed soil surveys should be 
used to determine management practices and remedial measures 
that are compatible with the great variety of soils and 
climates in the areas where these croplands are found. 

2 . The various educational, financial, and technical assistance 
programs of federal, state, and county agencies should be , 
used to increase productivity and protect the soil resource.— 

3 . Farm management practices that retard runoff and reduce the 
sediment yield should be used; a suggested list is presented 
in the table "Guidelines for Land Use and Minimum Conservation 
Treatment of Land Suited for Cultivation" on the following 
pages. 

Road Guidelines 


1 . Soil and geologic conditions should be investigated so that 
road locations can be planned to avoid steep slopes and 
areas of unstable soil and rock. In potential problem areas, 


y 


See the chapter 


"Opportunities for Development through USDA Programs.' 


97 









excavation and soil disturbance should be minimized even 
though the best alignment may sometimes be sacrificed. 

2 . Roads should be constructed during the dry season. Full 
inspection during all construction phases is essential. 

3 . Except in very steep terrain, cutbank slopes should be no 
steeper than l-l/2 to 1, and fill slopes no steeper than 2 to 
1 . Slopes should be interrupted by intermediate terraces at 
20 -foot vertical intervals. Adequate surface and subsurface 
drainage should be provided for all slopes and terraces. 

4. All cut and fill slopes that will support vegetation should be 
protected from erosion by seeding grasses, planting shrubs 

or trees, and applying mulch and fertilizer. 

5 . Excess material should be end-hauled to safe disposal sites 
where it will not erode into streams. 

6 . All fills should be sufficiently compacted during construction, 
and decomposable material should be eliminated from fill slopes. 

7 - When it is absolutely necessary to construct roads in unstable 
soil and landslide areas, particular attention should be given 
to surface and subsurface drainage. 

8 . Roads should be located so that fills will not encroach upon 
streams during peak flows. Riprap and retaining walls should 
be provided to protect fills when it is necessary to locate 
them within high-water elevations at culvert or bridge cross¬ 
ings . 

9- Fording of live streams with construction equipment should be 
avoided. 

10 . The location of stream crossing points should be selected to 
minimize the disturbance to streambanks and streamflow. The 
natural stream channel gradients should not be altered. Bridges 
or culverts should be provided at all watercourses for both 
temporary and permanent roads. Bridge piers and abutments 
should be aligned to minimize deflection of current. Culverts 
should be designed to permit the free movement of fish. 

11 . Adequate surface drainage facilities should be installed. 
Downdrains and energy dissipators should be installed at 
outlets of drainage ditches and culverts to prevent outflow 
water from being discharged directly onto unprotected slopes. 
Whenever possible, culvert outlets should be located in exist¬ 
ing waterways or in rocky areas. In erodible channels, energy 
dissipators should be provided at culvert outlets. Surfaced 
dips or outsloping should be considered for lower-standard 
roads to prevent accumulation of drainage flows. Road grades 
should be limited to six percent. 


98 








Guidelines for Lund Use and Miniiuuin Conservation 
Treatment of Land Suited for Cultivation 
(By Land Capability Class and Subclass - L.C.S.) 


(Southern Basins) 


L.C.S. 

Area 

( Sq . Mi . 

Land Management 

Problems 

Suitable Alternate 
Agricultural Land Uses-^ 

Minimum Conservation Treatment _ ” ^ 

I 

25 

No permanent problems. 

Irrigated 

Cropland 

fow Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 




Orchard 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Minimum Tillage 

Irrigation Water Management 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-Irrigated 

Cropland 

Row Crops 

FieLd Crops 

Conservation Cropping System 




Orchard 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Minimum Tillage 

He 

LOO 

Erosion hazard due to 
sloping land. Some soils 
are gravelly and have 

Lower available water 
capacity. 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 




Orchard 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Minimum Tillage 

Irrigation Water Management 




Pastureland 
(and Hayland) 

Pasture Proper Use 

Irrigation Water Management 




Non-Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Minimum Tillage 




Orchard 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Minimum Tillage 

IIv 

145 

Overflow. 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 




Orchard 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Minimum Tillage 

Irrigation Water Management 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 




Orchard 

Vineyard 

SmaLl Fruits 

Cover and Green Manure Crop, Minimum Tillage 



Somewhat poor drainage; 
maintenance of drainage 
system. 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 
(drainage) 




Orchard (pears) 
Vineyard 

Small Fruits 

Irrigation Water Management 

Mininun Tillage, or Cover and Green Manure Crop 
(drainage) 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping Syaten 

Mininun Tillage 
(drainage) 





Orchards (pears) 
Vinayard 

Small Fruits 

Mininum Tillage, or Cover and Green Manure Crop 
(drainage) 


99 






































Guidelines for Land Use and Minimum Conservation 
Treatment of Land Suited for Cultivation 
(By Land Capability Class and Subclass - L.C.S.) 


(Southern Basins) 


t.c.s. 

Area 

(Sq.Ml.) 

Land Management 

Problems 

Suitable Alternate 
Agricultural Land Uses-^' 

Minimum Conservation Treatment 2/ - 3/ 

ii* 

25 

Fin* texture, slow 
permeabl1icy. 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 

Minimum Tillage 
(drainage) 




Orchard 
(Cherries 
not adapted) 

Cover and Green Manure Crop, or Minimum Tillage 

Irrigation Water Management 




Pastureland 
(and Hay land) 

Irrigation Water Management 

Pasture Proper Use 




Non-Irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Minimum Tillage 

HI* 

*3 

Erosion hazard due Co 
sloping land. Some soils 
sr* very grsvclly snd 
hsv* low available water 
capacity. 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Irrigation Water Management | 

Minimum Tillage 




Ordhard 

Vindyard 

Small Fruits 

Cover and Green Manure Crop, or Mulching 

Irrigation Water Management 

Minimum Tillage 




Pastureland 
(and Hay land) 

Irrigation Water Management 

Pasture Proper Use 




Non-Irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Mlnlssim Tillage 




Orchard 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Mil ching 

Minimum Tillage 



Erosion hazard du* Co 
sloping land. ResCrlcCed 
rooting. Slow subsoil 
permeability. 

irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Irrigation Water Management 

Minimum Tillage 




Orchard(marginal) 
Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Mulching 

Irrigation Water Management 

Minimum Tillage | 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-Irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 




Vineyard 

Cover and Green Manure Crop, or Mulching 

Minimum Tillage 

IJIv 

80 

Wetness, poor drainage, 
may have some salts 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 

Minimum Tillage 
(drainage) 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 
(drainage) 




Non-lrrlgated 

Cropland 

Field Crops 

Conservation Cropping System 

Minimum Tillage 
(drainage) 


100 

































uux.u.e j-xxxea iur ijcixxu. uae ct,xxu i'oxxxxiuuxix ^uxisex'Vct, oxuxx 


Treatment of Land Suited for Cultivation 
(By Land Capability Class and Subclass - L.C.S.) 


(Southern 


L.C.S. 

Area 
(Sq.Ml.) 

Lund Management 

Problems 

Suitable Alternate , 

Agricultural Land Uses—' 

Minimum Connervutlon Trea1.menU-/””-i/ 

IVe 

315 

Erosion hazard due to 

Irrigated 




sloping land.Soil depth. 
Acidity for seme crops. 

Cropland 

Field Crops 
(Hay) 

Conservation Cropping System 

Crop Residue Use 

Irrigation Water Management 

Minimum Tillage 

Sprinkler Irrigation System 




Orchard(except 

Pears - other 
orchards are 
marginal in some 
areas) 

Vineyard 

Small Fruits 

Cover and Green Manure Crop, or Mulching 

Crop Residue Use 

Sprinkler Irrigation System 

Irrigation Water Management 

Minimum Tillage 




Pastureland 
(and Hayland) 

Sprinkler Irrigation System 

Irrigation Water Management 

Pasture Proper Use 




Non-irrigated 





Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 




Orchard 

(marginal in some 
areas) 

Vineyard 
(marginal in 
some areas) 

Cover and Green Manure Crop, or Mulching 

Crop Residue Use 

Minimum Tillage 



Erosion hazard due to 

Irrigated 




sloping land. Soil depth. 
Slow subsoil permeability. 
Acidity for some crops. 

Pastureland 
(and Hayland) 

Sprinkler Irrigation System 

Irrigation Water Management 

Pasture Proper Use 




Non-irrigated 





Cropland 

Field Crops 
(not well 
adapted) 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 




Orchard(existing) 

Vineyard 

(existing) 

Cover and Green Manure Crop, or Mulching 

Crop Residue Use 

Minimum Tillage 

IVs 

15 

Low available water capac- 

Irrigated 




ity. Low Fertility. 

Erosion hazard. Deposition. 
Very gravelly. 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Irrlgution Water Munagoment 

Minimum Tillage 




Vineyard 

Cover and Green Manure Crop, or Mulching 

Crop Residue Use 

Irrigation Water Management 

Minimum Tillage 




Pastureland 

Pasture Proper Use 

Irrigation Water Management 


l/ Other suitable alternate agricultural land uses for each of the Land Capability Classes and Subclasses are: 
Non-irrigated Pastureland 
Recreation Land and/or Wildlife Land 
Some soils in Classes He, IIw, IHe, and IVe are suited to Woodland. 

Land uses not shown indicate their general unsuitability. 


2/ Pasture Proper Use and Woodland Proper Use are the minimum conservation treatments for Non-irrigated Pastureland and 
Woodland respectively. 

No specific practices are indicated as minimum conservation treatment for Recreation Land and/or Wildlife Land because of 
the wide variety of activities that might occur under these land uses. Applicable conservation treatment should assure 
maintenance of land and water resources. 


There are many structural and other conservation practices that are supplemental to the minimum conservation treatment 
practices such as grassed waterways and outlets, strearabank protection, and diversion terraces. 

Definitions of minimum conservation treatment practices: 

Conservation Cropping System - Growing crops in combination with needed cultural and management measures. Cropping systems 
include the use of rotations that contain grasses and legumes, as well as sequences in which the desired benefits are 
achieved without the use of such crops. 

Cover and Green Manure Crop - A crop of close-growing grasses, legumes, or small grain used primarily for seasonal protec¬ 
tion and for soil improvement. It usually occupies the land for a period of one year or les6, except where there is perma¬ 
nent cover as in orchards. 


Crop Residue Use - Utilizing plant residues left in cultivated fields to prevent erosion and improve the soil. 

Irrigation Water Management - The U6e and management of irrigation water, where the quantity of water used for each irriga¬ 
tion is determined by the moisture-holding capacity of the soil and- the need of the crop, where the water is applied at a 
rate and in such a manner that the crops can use it efficiently and significant erosion does not occur, (includes the tim¬ 
ing of irrigations to meet crop needs, the control and adjustment of stream sizes to prevent erosion, and the control of 
lengths of "set" to reduce water losses.) 

Minimum Tillage - Limiting the number of cultural operations to those that are properly timed and essential to produce a 
crop and prevent soil damage. 

Mulching - Applying plant residues or other suitable materials, not produced on the site, to the surface of the soil. 

Pasture Proper Use - Grazing at an intensity which will maintain adequate cover for soil protection and maintain or im¬ 
prove the quantity and the quality of desirable vegetation. 

Woodland Proper Use - Treating woodlands in a manner which will maintain adequate cover for soil and water conservation, 
and maintain or improve the quantity and quality of desirable wood crops, by the application of one or more woodland pro¬ 
tection and/or woodland conservation practices. 


Basins 































Guidelines lor Land Use and Minimum Conservation 
Treatment of Land Suited for Cultivation 
(By Land Capability Class and Subclass - L.C.S.) 

(Northern Basins) 


L.C.S. 

Are* 

(Sq . Ml. ) 

Lend Management 

Problems 

Suitable Alternate 
Agricultural Land Uses!/ 

Minimum Conservation Treatment!/ “ —' 

He 

90 

Erosion hazard due to 
sloping land. Some 
soil* are gravelly and 
have lover available 
water capacity. 

Irriga ted 

Cropland 

Row Crops 

Field Crops 

Irrigation Water Management 

Crop Residue Use (only in Siskiyou County) 

Minimum Tillage (only in Siskiyou County) 

Conservation Cropping System 




Orchard (only In 
Del Norte County) 
Vineyard (only In 
Del Norte County) 

Cover and Green Manure Crop, or Minimum Tillage ! 

Irrigation Water Management 




Paatureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use (only in Siskiyou County) 

Minimum Tillage (only In Siskiyou County) 




Orchard (only In 
Del Norte County) 
Vineyard (only In 
Del Norte County) 

Cover and Green Manure Crop, or Minimum Tillage 

IIv 

40 

Overflow 

Irrigated 

Cropland 

Row Crops 

Field Crops 

Conservation Cropping System 

Irrigation Water Management 




Pastureland 

Irrigation Water Management 

Pasture Proper Use i 




Non-lrrlgated 

Cropland 

Field Crops 

Conservation Cropping System 

III* 

235 

Erosion hazard due to 
sloping land. Some 
soils are gravelly or 
sandy and have low 
available water capacity. 

Irriga ted 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 

Irrigation Water Management 




Orchard (only In 

Del Norte County) 
Vineyard (only In 
Del Norte County) 

Cover and Green Manure Crop, or Minimum Tillage 

Irrigation Water Management 

Sprinkler Irrigation System 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-lrrlga ted 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 



Erosion hazard due to 
sloping land. Restricted 
rooting. Slow aubsoll 
permeability. 

Irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 

Irrigation Water Management 




Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 




Non-irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 

IIIv 

150 

Wetness, poor drainage 

Some soils have clayey 
texture. Some soil* 
have slight or moderate 
alkali. 

Irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 
(Drainage) 

Irrigation Water Management 

Minimum Tillage 

Toxic Salt Reduction (in soils that have moderate 

alkali) 




Paatureland 
(and Hayland) 

(Drainage) 

Irrigation Water Management 

Pasture Proper Use 

Toxic Salt Reduction (in soil* that have moderate 

alkali) 




Non-irrigated 

Cropland 

Field Crops 

Conaervatlon Cropping System 

Crop Residue Use 

Minimum Tillage 


102 






































Guidelines for Land Use and Minimum Conservation 
Treatment of Land Suited for Cultivation 
(By Land Capability Class and Subclass - L.C.S.) 


(Northern Basins) 


L.C.8. 

Area 

(Sq.Hi.) 

Land Management 

Problems 

Suitable Alternate 
Agricultural Land Uaea^' 

2/ - 3/ 

Minlmun Conservation Treatment— — 

Ills 

140 

Soils are sandy or 
gravelly and have low 
available water capac¬ 
ity. Wind erosion 
hazard. Soils have 
low fertility 

Irrigated 

Cropland 

Field Crops 

Row Crops 

Conservation Cropping System 

Crop Residue Use 

Irrigation Water Management 

Sprinkler Irrigation System 



Pastureland 
(and Hayland) 

Pasture Proper Use 

Sprinkler Irrigation System 

Irrigation Water Management 




Non-irrigated 

Cropland 

Field Crops 

Conservation Cropping System 

Crop Residue Use 

Minimum Tillage 

IVe 

130 

Erosion hazard due to 
eloping land. Soil 
depth. Slow subsoil 
permeability. 

Irriga ted 

Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 

Sprinkler Irrigation 




Non-irriga ted 

Cropland 

Field Crops 

Conservation Cropping System 

Contour Farming 

Crop Residue Use 

Minimum Tillage 

IVw 

100 

Wetness, somewhat poor 
drainage, and strong 
alkali. 

Irrigated (Sub) 

Pastureland 
(and Hayland) 

Irrigation Water Management 

Pasture Proper Use 

Toxic Salt Reduction 




Non-irrigated 

Pastureland 
(and Hayland) 

Pasture Proper Use 

IVs 

370 

Soils are coarse-tex- 
tured, very gravelly, 
or stony and have lower 
available water 
capacity. 

Non-irrigated 

Pastureland 
(and Hayland) 

Pasture Proper Use 


1/ Other suitable alternate agricultural land uses for each of the Land Capability Classes and Subclasses are: 

Non-irrlgated Pastureland 
Recreation Land and/or Wildlife Land 
Some soils in Classes lie, IIw, Ille, and IVe are suited to Woodland. 

Land uses not shown indicate their general unsuitability. 

2/ Pasture Proper Use and Woodland Proper Use are the minimum conservation treatments for Non-irrigated Pastureland and 
Woodland respectively. 

No specific practices are indicated as minimum conservation treatment for Recreation Land and/or Wildlife Land because of 
the wide variety of activities that might occur under these land uses. Applicable conservation treatment should assure 
maintenance of land and water resources. 

There are many structural and other conservation practices that are supplemental to the minimum conservation treatment 

practices such as grassed waterways and outlets, streambank protection, and diversion terraces. 

3/ Definitions of minimum conservation treatment practices: 

Conservation Cropping System - Growing crops in combination with needed cultural and management measures. Cropping systems 
Include the use of rotations that contain grasses and legumes, as well aa sequences in which the desired benefits are 
achieved without the use of such crops. 

Cover and Green Manure Crop - A crop of close-growing grasses, legumes, or small grain used primarily for seasonal protec¬ 
tion and for soil improvement. It usually occupies the land for a period of one year or less, except where there is perma¬ 
nent cover as in orchards. 

Crop Residue Use - Utilizing plant residues left in cultivated fields to prevent erosion and improve the soil. 

Irrigation Water Management - The use and management of irrigation water, where the quantity of water used for each irriga¬ 
tion is determined by the moisture-holding capacity of the soil and the need of the crop, where the water is applied at a 

rate and in such a manner that the crops can use it efficiently and significant erosion does not occur. (Includes the tim¬ 

ing of irrigations to meet crop needs, the control and adjustment of stream sizes to prevent erosion, and the control of 
lengths of "set" to reduce water losses.) 

Minimum Tillage - Limiting the number of cultural operations to those that ore properly timed and essential to produce a 
crop and prevent soil damage. 

Mulching - Applying plant residues or other suitable materials, not produced on the aite, to the surface of the soil. 

Pasture Proper Use - Grazing at an intensity which will maintain adequate cover for soil protection and maintain or im¬ 
prove the quantity and the quality of desirable vegetation. 

Woodland Proper Use - Treating woodlands in a manner which will maintain adequate cover for soil and water conservation, 
and maintain or improve the quantity and quality of desirable wood crops, by the application of one or more woodland 
protection and/or woodland conservation practices. 


103 



























Road culvert outletting above ground on unstable soil causing 
erosion. Landslide on far hillside. scs photo 3-5735-2 



Confluence of three large 3 deep gullies caused by three small 
cross-drains on road with improper outlet conditions . 

104 


SCS PHOTO 3-5735-16 








12 . All roads that will be used during the wet months should be 
paved, and unpaved roads should be closed during this period. 

13 . All drainage ditches, dips, and culverts should be inspected 
each year and repaired and cleaned out prior to the rainy 
season. Maintenance operations should not remove the toe of 
cutbanks, and the excess material should not be sidecast or 
deposited on streambanks. 

1 4 . All roads should be inspected periodically for possible 
maintenance needs. 



This road was constructed across an oxbow and is encroaching 
upon the stream. scs phot ° 3-5735-7 


105 







Mining Guidelines 



1 . Channel systems formerly used in hydraulic mining operations, 
old tailing piles, and dredging should be restored to their 
natural state. This is needed to prevent further erosion 

and sedimentation and to enhance scenic beauty. Land leveling, 
bank sloping, installing gully plugs, and, in some instances, 
channel diversion are recommended to shape the terrain for 
planting. 

2 . Specific regulations should be developed to require mining 
operators to use proper restoration measures for controlling 
erosion and sediment and for re-establishing adequate vegetal 
cover. 

3 . A monitoring system should be developed to enforce water 
quality standards for mining effluent where it is discharged 
into rivers. 


Gold dredge tailings in the Trinity River at the upper end of 
Trvmty Lahe. scs photo 3-5735-10 


106 








Old hydraulic mine with severely eroded mine tailings in fore¬ 
ground and severely eroded mining escarpment face in back¬ 
ground. SCS PHOTO 3-5735-2 



107 


STREAMBANKS 


The application of management guidelines will help to reduce the sedi¬ 
ment yield influenced by man's activities, especially in 2nd and 3rd 
order channels. 

1 . Clearing and snagging: Snags, drifts, sand bars, or other 
obstructions to channel flow should be removed to increase 
the channel capacity, to prevent bank erosion by eddies, to 
prevent the formation of sand bars, to minimize the occurrence 
of debris jams, and to eliminate the diversion of flows 
directly into erodible streambanks. 

a. All trees, stumps, and brush within the channel should be 
cut as low as possible. 

b. Large, bulky, and top-heavy trees that are undercut by 
streamflows and might topple over should be removed to 
avoid causing debris jams and deflection of streams. 

c. Trees selected should be felled so as to avoid damage to 
other trees and the channel. 

d. Trees, logs, and all other non-salvageable combustible 
material resulting from clearing and snagging operations 
should be removed from the channel area. 

e. Where sand bars have built up, especially after heavy 
flooding, and have caused the channel to meander and expose 
raw banks, removal of material to redirect flows away 
from the raw banks is sometimes necessary. These raw 
banks should then be shaped to a stable slope and planted 
with suitable vegetation to help reduce further bank 

erosion. 

f. Where removal will result in channel erosion, either the 
clearing and snagging should not be done, or other practices, 
such as riprap or other revetment, should be installed 
concurrently. 

g. Removal of vegetation on the toe of landslides should be 
done selectively and with good judgement. 

2 . Trash, debris, slash, or other materials should not be dumped 
into stream channels or left where it could reach channel flows. 

3 - Surface waters should not be discharged directly over the edges 
of the streambanks. Diverted flows from farm drainage ditches 
and road gutters should be provided with adequate outlets. 

4 . Vegetal cover along streambanks should be encouraged as long as 
it does not restrict channel capabilities. 


108 







5- Temporary earth fills that may impede high flows should be 
removed prior to the rainy season. 

6. Strong action should be taken to control activities in and 
adjacent to stream channels and unstable areas. Regulations 
such as the state water quality standards, building codes, and 
regulations of planning commissions, fish and game commissions, 
road commissions, and other responsible bodies should be en¬ 
forced to reduce sediment and alleviate debris problems. The 
general public should be informed of the problems and the 
consequences associated with streambank erosion. More stringent 
controls should be enacted when needed. 

7- The management guidelines for logging and road building activi¬ 
ties (discussed elsewhere in this section) should be applied 
where appropriate since they are interrelated with those for 
streambanks. 

8. Other considerations, such as the effect on wildlife habitat 
and scenic beauty, should be taken into account when any 
management guideline is contemplated. 

LANDSLIDES 

The following are guidelines for prevention and reduction of sediment 

yield from man-caused landslides: 

1. Soils and geologic information should be used to map potential 
problem areas and the maps made available to interested 
parties, such as construction engineers and foresters, to 
enable them to plan their operations accordingly. 

2. Landslide areas supporting timber should not be logged. 

3- Roads, skid trails, and landings should not be built in 
geologically unstable areas. 

4. Grazing should be eliminated during periods when the soils 
are appreciably moist in areas experiencing rapid soil creep 
(areas of rumpled topography and minor sliding). 

5. Conversion of timberland to grassland should not be made in 
geologically unstable areas. 

6. Where life or economic interests are endangered by landslides, 
it may be desirable to stabilize a slide area such as by end- 
hauling deposits to the toe of a slide. 

Other Studies on Landslide Problems 


The first management guideline for landslides suggests mapping potential 
problem areas before proceeding with planned developments. Landslide 
studies, such as the following made by various agencies or professional 


109 







societies, will guide planners in designing programs for mapping land¬ 
slides and unstable terrain. 


1. The Association of Engineering Geologists has assembled a map 
showing the distribution of known landslides that are over 100 
feet in width or height of Ventura, Los Angeles, and San 
Diego Counties. 2J 

2. The California Department of Water Resources, Corps of Engineers, 
and Bureau of Reclamation are making detailed studies around 
proposed reservoir sites. 


3- The U.S. Forest Service Pacific Southwest Forest and Range 
Experiment Station is studying mass erosion processes in the 
North Coastal Area. ^Station personnel have also mapped land¬ 
slides and potentially unstable areas in Nicasio Valley in - 
Marin County to provide the Planning Commission with information 
about the distribution of landslide zones and other geologic 
hazards. 

4. Other studies by the U.S. Geological Survey and the State 
Division of Mines and Geology are in progress or are- being 
published. 



Landslide badly gullied from poor drainage conditions. Drain¬ 
age pipe on the slide ends 25 feet above road and is causing 
gully. 


1/f.b. Leighton, "Preliminary Map Showing Landslide Locations in a 
Portion of Southern California," in Engineering Geology in Southern 
California , Richard Lung and Richard Proctor, eds., pp. 194-207, 
(Los Angeles, Association of Engineering Geologists, 1966). 


110 













Landslide at toe of Trinity Dam on the east abutment. Treat¬ 
ment measures on slide include benching at intervals and a 
system of drain lines and collector pipes. scs photo 3 - 5735-5 

EFFECTS OF THE MANAGEMENT GUIDELINES 

If the proposed management guidelines are implemented, annual sediment 
volume from sheet and gully erosion, streambank erosion, and landslides 
will be reduced 2,080 acre-feet. This reduction amounts to more than 
sixty percent of the sediment now attributed to man's activities. 

Sheet and gully erosion can be reduced by 390 acre-feet per year 
with the largest reductions resulting from improved road construction and 
logging methods. Streambank erosion can be reduced 8l0 acre-feet per 
year with the guidelines. The largest reduction would be that from 
the landslides, which would be about 880 acre-feet per year. If the 
guidelines are not followed, sediment yields will increase with man's 
increasing activities. Natural erosion will not be greatly affected 
by the guidelines. 


SUMMARY OF THE EFFECTS OF THE 
LAND TREATMENT PROGRAM 


The physical, biological, and social effects of the land treatment 
program are summarized in this section. The effects of the program on 
fish and wildlife, scenic beauty, recreation, and the economy were not 
evaluated in monetary terms. 


SEDIMENT YIELD 


The land treatment program would reduce sediment yield in the next 50 
years by an estimated 2,890 acre-feet per year. 


Ill 










All remedial and production improvement programs will reduce sediment 
yield except that on public grassland; the reduction in this case was 
considered negligible because existing sediment from this source is 
minor. The following tabulation summarizes the sediment reduction that 
can be expected from the various programs. 

Annual Sediment Yield 
(Acre-Feet) 


Sheet 


Item 

Streambahk 

Landslides 

& Gully 

Total 

PRESENT CONDITIONS 
Northern Basins 
Southern Basins 
Total 

2,860 

2,220 

5,080 

1,850 

940 

2,790 

1,230 

1,790 

3,020 

5,940 

4,950 

10,890 

FUTURE WITHOUT PROGRAMS 
Northern Basins 
Southern Basins 

Total 

2,860 

2,220 

5,080 

2,330 

1,180 

3,510 

1,330 

2,690 

4,020 

6,520 

6,090 

12,610 

FUTURE WITH PROGRAMS^/ 
Northern Basins 
Southern Basins 

Total 

2,400 

1 ? 870 

4*270 

1,745 

885 

2,830 

705 

2,115 

2,820 

4,850 

4,870 

9,720 

Reduction in 

Sediment Yield 




(Acre 

-Feet) 



Item 

Streambank 

Landslides 

Sheet 
& Gully 

Total 

REMEDIAL PROGRAM 

0 

0 

810 

810 

MANAGEMENT GUIDELINES 

810 

880 

390 

2,080 

Total 

810 

880 

1,200 

2,890 


1 / 

Includes effects of remedial program and management guidelines. 


112 






































PRODUCTION 


Remedial and production improvement programs would provide an overall 
increase in forage and timber production. In the case of type con¬ 
version programs, some forage production would be shifted to production 
of timber; however, the net result is an overall increase in both types 
of production. The road program would have very little direct effect 
on production. The following tabulation summarizes the increases or 
decreases in forage and timber production that could be expected if the 
programs were installed: 


Program 

Private Grassland 
Public Grassland 
Brushland 
Roads 

Total 


Annua1 

Forage Production 
(Animal-Unit-Months ) 

+433,000 
- 8,000 
0 


+425,000 


Annual 

Timber Production 
(1,000 Cubic Feet) 

+ 8,000 
+ 5,000 
+19,000 


+32,000 


WATER QUANTITY AND QUALITY 


Hydrologic studies in the Eel and Mad River Basins, presented in 
Appendix No. 1, indicate that the land treatment program would reduce 
runoff from 2-year recurrence interval storms of up to 10-day duration. 
The amount of reduction that could be realized from the various remedial 
programs varied from about 5 to 30 percent in the area to be treated. 

Use of the management guidelines would also reduce runoff, but probably 
by a lower percentage. In most cases, the reductions would be more 
noticeable in the smaller upstream creeks than in the larger downstream 
ones. The percent reduction in runoff would be less during the larger 
storms than it would be for the smaller ones. 


The temporary sedimentation that occurs during the rainy season would be 
reduced by about 23 percent from the application of the land treatment 
program. This reduction would also be more noticeable in the smaller 
creeks. The chemical characteristics of the water should remain unchanged 
except for a possible minor increase in nitrogen caused by fertilization 
from the private grassland program; this slight increase would have 
little effect on water quality. 

FISH AND WILDLIFE 

With the reduction in sediment yield from installation of the land 
treatment program, fewer fish eggs would be lost from sediment deposi¬ 
tion in streams, spawning beds and aquatic food production would be 
improved, and the population of anadromous fish would be increased. 

These changes would occur mostly in the smaller upstream creeks. The 
resulting improvement in vegetal cover along streambanks would improve 
the natural habitat for both fish and wildlife. 


113 







As the vegetal cover is improved, wildlife food arid cover protection 
will be enhanced and game populations will increase. Programs that 
convert grass or brush to timber generally reduce habitat for deer, 
but may enhance that for other species of wildlife. 

SCENIC BEAUTY AND RECREATION 

Reduction in eroded areas and improved vegetal cover would enhance 
the natural beauty of the area, especially in reforested areas and 
a long s treamba nks. 

As wildlife habitat and scenic beauty are improved, recreation oppor¬ 
tunities will increase. Increased populations of fish and game will 
provide more hunting and fishing, and more people should engage in 
tourism, camping, and other forms of recreation. 

MONETARY AND SOCIAL BENEFITS 

Incomes should be increased through improved productivity on grass and 
timber land if the land treatment program is installed, and enterprises 
should be placed on a firmer financial basis. This increase in primary 
income would enhance profits of supporting industries and local business, 
and the existing unemployment and underemployment would be reduced. 

The overall living conditions in the basins should improve. 

Adherence to management guidelines for future road construction will 
reduce operation and maintenance costs, and roads will be safer and 
more useful daring and after intense storms. There will be less likeli¬ 
hood of travelers being stranded and communities being isolated during 
major storms. 

Recreation is the third largest land use in the basins and is an impor¬ 
tant source of local income. With the predicted increase in recreation 
activity from installation of the program, the income from this source 
will increase accordingly. 

Improvements in productivity, recreation, and scenic beauty will increase 
the value of the land. 


IMPLEMENTATION 


A large land treatment program has certain implementation problems and 
needs that must be overcome before a basinwide installation can be 
successful. This section presents major problems and needs that may 
be encountered in installing the program. 

PROBLEMS 

Implementing programs on privately owned lands is often considerably 
more difficult than it is on publicly owned lands. The Southern Basins 
are essentially privately owned and, therefore, present a greater problem 


114 







than the Northern Basins. Generally, the agencies with jurisdiction 
over public lands have the authority, policy direction, and technical 
expertise to implement needed programs. Quite often, however, funding 
is the limiting factor. 

En the case of privately owned lands, the success of the program depends 
entirely on the voluntary participation of the landowners and operators. 
Many of the agricultural enterprises in the basins are marginal 
operations, and landowners show little apparent interest in spending 
money for improvements. The entire North Coastal Area is considered 
an economically depressed area by the Economic Development Administration, 
and all counties in the study area are eligible for full financial 
assistance. 

Although the proposed remedial measures provide both monetary and non¬ 
monetary benefits, the returns are sometimes not realized for long 
periods. In the case of reforestation measures, it will be many 
years before any income is received from the sale of thinnings and at 
least 60 years before the major income from sawtimber harvests can be 
realized. Even grazing benefits may not be realized for the first year 
or two until the grassland is rehabilitated. 

Land in the severe erosion class will be excluded from livestock graz¬ 
ing, and, therefore, will yield little or no income. Much of this 
area would be suitable for wildlife production after planned treatment 
that emphasized planting woody vegetation. Landowners will probably 
still have to pay property taxes based on grazing use, and this may 
discourage landowners from participating in the program. 

Many landowners do not live on their property and are often not aware 
of the erosion problems that can be created by unconcerned operators 
or leasees. Some people buy land mainly for speculation of future 
sale profits, and these owners are seldom interested in spending money 
for improvement, especially when the benefits are long term. 

Under the Rural Environmental Assistance Program, administered by the 
USDA Agricultural Stabilization and Conservation Service, federal funds 
are available on a cost-sharing basis to install remedial practices for 
soil and water conservation problems. For many of these practices, the 
federal contribution is too small to encourage landowners to make the 
large investments necessary to install the recommended program. 

NEEDS 

Before programs are installed, detailed surveys of soils, vegetal cover 
conditions, and needs should be made. A plan listing specific treat¬ 
ments for each problem area should be developed with each landowner. 
Detailed economic studies are needed to evaluate all on-site and down¬ 
stream benefits that will accrue from installing both the remedial 
measures and the management guidelines, especially those that affect 
the general public. These benefits may include improved water quality, 
reduced sediment yield, improved fish and wildlife habitat, increased 
recreational value, increased land value, reduced road maintenance, 
increased scenic beauty, and conservation of vegetal resources for 


115 


future use. Any adverse affects, such as decreased water quality 
caused by fertilization or lower prices caused by increased production, 
also need to be studied. 

A special study should be made on cost sharing .to arrive at an equitable 
distribution of program installation costs between public and private 
interests. 

An effective educational and informational program is essential to the 
success of the program. Landowners, local officials, and the general 
public should be made aware of the need for a land treatment program 
and the benefits that can be derived from its installation. Local 
officials and landowners should recognize the erosion problems that may 
result from improperly planned and installed construction projects, and 
they should be informed of the technical consulting services and finan¬ 
cial assistance programs available to them through federal and state 
agencies. 

Property tax assessments on land to be excluded from livestock grazing 
should be studied in detail to determine an equitable method of com¬ 
pensating the landowner for this financial loss. Tax relief could be 
accomplished locally by removing these lands from the tax -rolls or 
reducing the taxes to a minimum, or compensation could be made by state 
or federal funds that would spread the costs over a larger tax base. 

The possibility of establishing land preserves for severely eroded 
lands similar to agricultural preserves under the California Land 
Conservation Act of 1965 should be investigated. 

It would be desirable to make studies regarding the capability of 
specific areas to provide light recreation use, such as hunting. The 
income from such enterprises may be sufficient to pay the property 
taxes and relieve the public of this burden. The initial installation 
of such a program may require cost sharing from public funds. 

Additional basic data is needed on landslides and their movement, stream- 
bank erosion, erosion effects on productive capabilities of forest soils, 
the relation between sediment and streamflow to salmon and steelhead 
populations, and other factors that affect land use and management. 
Research efforts should be expanded and coordinated so that land managers 
can be furnished firm guides that will enable them to avoid some of the 
mistakes of the past and to achieve greater productivity. 


116 





OPPORTUNITIES FOR DEVELOPMENT 
THROUGH USDA PROGRAMS 


The U.S. Department of Agriculture has the authority and responsibility, 
under various laws, to promote wise use of land and water resources 
through land treatment and construction programs. The following 
sections summarize those development programs that are considered 
applicable under the limited assumptions in this study. A more detail¬ 
ed description of these programs is included in the main report. 


WATERSHED PROTECTION AND FLOOD PREVENTION PROJECTS 

(PUBLIC law 566) 


The Watershed Protection and Flood Prevention Act (Public Law 566, 

83rd Congress, 1954 , as amended) authorizes the expenditure of federal 
funds through USDA to plan and carry out a program for the development, 
use, and conservation of the Nation's soil and water resources. The 
primary purpose of potential projects must be watershed projection, 
flood prevention, irrigation, or drainage; other purposes such as 
recreation, fishery enhancement, municipal and industrial water supply, 
and other water management measures may also be included. SCS pro¬ 
vides administrative leadership for cooperative federal assistance to 
local organizations in planning and implementing projects for small 
watersheds (up to 250,000 acres). Technical assistance, cost-sharing, 
and long-term credit are the main contributions provided by USDA in 
the development of PL 566 projects. 

Nineteen potential watersheds have been identified by watershed investi¬ 
gation or preliminary investigation reports as being feasible projects 
for an early action program. These are described in the main report 
of this study. The watershed projects will reduce sediment and erosion 
with land treatment and structural measures. The land treatment 
measures required in these projects will have similar effects to those 
already described in this appendix. The structural measures will trap 
11,990 acre-feet of sediment, retard 15,700 acre-feet of floodwater, 
store 15,100 acre-feet of recreation water, provide 82,794 acre-feet 
of irrigation supply, and furnish 25,760 acre-feet of municipal water 
supply. 

As a part of the total project cost, additional funds could be made 
available for technical services to accelerate installation of that 
portion of the land treatment program within the watershed boundary. 

The amount of acceleration funds needed would depend on the size of 
the current resource conservation district program in the watershed; 
this district program is described in the following section. 


117 










RESOURCE CONSERVATION DISTRICT PROGRAMS 


Resource conservation districts are legally constituted units of state 
government that administer soil and water conservation work within 
their boundaries. Each district is governed by an elected board of 
local people, usually resident landowners or operators, and has the 
authority to enter into working agreements with other government 
agencies and with private interests. 

The following conservation districts cover about 87 percent of the 
study area: 


Resource Conservation District 

Gold Ridge 
Santa Rosa 
Sotoyome 

Mendocino County 
Westlake 
East Lake 
Napa County 
Trinity County 
Siskiyou 
Shasta Valley 
Butte Valley 
Lava Beds 

Central Modoc 


County 

SCS Work Unit < 

Sonoma 

Santa Rosa 

S onoma 

Santa Rosa 

Sonoma 

Santa Rosa 

Mendocino 

Ukiah 

Lake 

Lakeport 

Lake 

Lakeport 

Napa & Sonoma 

Napa 

Trinity 

Redding 

Siskiyou 

Yreka 

Siskiyou 

Yreka 

Siskiyou 

Tulelake 

Siskiyou & 


Modoc 

Tulelake 

Modoc & Lassen 

Alturas 


There are no resource conservation districts in Humboldt and Del Norte 
Counties. 

The Soil Conservation Service has working agreements to provide assist¬ 
ance to these districts. District programs, which are carried out 
through cooperative agreements with individuals or groups, include: 

1. the treatment and use of cropland, rangeland, woodland, and 
forest, including the problems incident to their conversion 
to urban uses; 

2. the improvement and protection of stream channels; and 

3. the development of water for irrigation, livestock, and 
recreation. 

Increasing emphasis is being given to the management and protection of 
the steep eroding mountain slopes. 

About 90 percent of the privately owned grassland in the basins is 
within one of the thirteen resource conservation districts. Each 
district is in a position to take leadership in implementing the 
land treatment program within its district boundary. 


118 










Modem cabins overlooking enclosed 3 stocked fish pond built 

with SCS assistance. SCS PHOTO ORC 82-13 



Woodland soil site correlation in Douglas-fir and Ponderosa 
pine area. scs photo ! - 3|7s - 6 


119 





CONSERVATION OPERATIONS (PUBLIC LAW 46 ) 


Public Law 46 , enacted by the 74 th Congress, established a national 
soil and water conservation policy and created the Soil Conservation 
Service (SCS). The law directed the SCS to develop a program to 
control and prevent soil and water losses and to reduce flooding and 
sediment hazards. 

The SCS has no enforcement powers, but carries out its responsibilities 
largely through working agreements with organized soil and water 
conservation districts. Technical services are available to districts 
and their cooperators to assist in planning, designing, and applying 
conservation practices. These services include soil surveys to help 
determine the capability and best use of land; planning to help 
determine needed conservation measures and programs; and engineering 
and geologic services to investigate, design, and assist in the instal¬ 
lation of structural measures. Technical services dealing with agronomy, 
biology, range management, and recreation are also available; however, 
according to the law, no funds are provided for installation of programs. 

The proposed technical services needed to install the remedial measures 
could be supplied by the SCS under the Conservation Operations Program, 
especially those in the grazing portion of the program. Technical 
services for the grazing program were estimated to be about $51?000 
a year during the 20-year installation period and $25,000 a year there¬ 
after. 


RURAL ENVIRONMENTAL ASSISTANCE PROGRAM 


The Agricultural Stabilization and Conservation Service (ASCS ) admin¬ 
isters the Rural Environmental Assistance Program (REAP; formerly 
the Agricultural Conservation Program -- ACP), through which they 
share with private landowners and operators the cost of installing 
conservation measures. This allows the installation of measures 
that are too expensive for private landowners, but that have long 
term benefits to soil and water resources. 

The ASCS State Committee determines measures eligible for cost sharing 
in the state and sets the maximum allowable payment rate. A 5 -member 
County Committee is elected annually by the farmers in each county and, 
assisted by a local office manager and staff, administers the program 
locally. After considering the most urgent conservation needs of the 
county, the Committee determines which of the eligible measures will 
be offered and establishes the local cost-sharing rates. Generally, 
the rates do not exceed 50 percent of the cost, but for erosion control 
practices they may be as high as 80 percent. 

All of the proposed remedial measures in the recommended land treatment 
programs for private grassland and timberland are eligible for federal 
cost-sharing under the REAP. Federal cost-sharing averages about 50 


120 








percent for practices on grasslands and varies from 50 to 70 percent 
for practices on timberland. REAP payments for practices in the 
eight counties of the basins totaled $ 450,000 in 1971 . 

A special REAP project could be formulated to install the land treat¬ 
ment program in the study area, and additional funds would be allotted 
for this purpose. The maximum amount of money that would probably be 
available under this type of project is about $100,000 a year for the 
20-year installation period. 


FARM AND HOME ADMINISTRATION LOAN PROGRAMS 


The Farmers Home Administration (FHA) provides loan programs and finan¬ 
cial and advisory assistance for: 

1 . Farmers to purchase and improve real estate; to buy livestock, 
equipment, and other essentials; and to finance forestry and 
recreational enterprises. 

2 . Farmers and rural residents to construct, purchase, or improve 
homes, farm service buildings, housing for domestic labor, and 
rental housing. 

3 . Groups of farmers and rural residents to develop and improve 
rural water supply systems, waste disposal systems, rural 
outdoor recreational facilities, and livestock grazing land. 

In addition, loans can be made to organizations to finance 
the local share of the cost of installing watershed protec¬ 
tion (Public Law 566) works of improvement. 

4 . Low-income rural families, on an individual family or 
cooperative group basis, to enable them to increase their 
incomes and make a modest improvement in their standards of 
living through loans for both agricultural and business enter¬ 
prises . 

In addition, FHA provides assistance to rural communities for planning, 
financing, and executing complete programs of economic development, 
including assistance in locating and using services of non-USDA programs 
to solve problems. The loan programs do not compete with those of 
other lenders, and financial management assistance accompanies each 
loan. Landowners who qualify for loans through private lending 
organizations are not eligible for loans under the FHA programs. The 
maximum loan available to each landowner is $60,000. 

FHA could loan money to qualified private landowners to pay their 
cost-share of installing the land treatment program. In 1969, FHA 
had about $1 million available for this type of loan for the entire 
state, but to date, no loans for grazing improvements have been made 
in California. 


121 









AGRICULTURAL EXTENSION SERVICE 


The Agricultural Extension Service (AES ) provides educational and 
informational services to landowners and operators, and maintains an 
office in each county in the basins. University of California farm 
advisors help the agricultural interests to keep up-to-date on the 
latest agricultural advances and to improve farming operations. Live¬ 
stock improvement and field trials on crops and fertilizers are part 
of AES activities. 

The farm advisors' offices and areas they serve are listed below: 

Farm Advisory Location Area Served 


Santa Rosa 
Kelseyville 
Ukiah 
Eureka 

Weavervilie 

Yreka 

Alturas 


Sonoma County 
Lake County 
Mendocino County 
Humboldt and Del Norte 
Counties 
Trinity County 
Siskiyou County - 
Modoc County 


AES will provide leadership in an educational and informational program 
to make landowners and the general public aware of the need for the 
land treatment program and the benefits that can be derived from its 
installation. Their technical advice on fertilization, seeding, and 
livestock management will be of valuable assistance in applying the 
grazing portion of the land treatment program. 


RESOURCE CONSERVATION AND DEVELOPMENT PROJECTS 


The U.S. Department of Agriculture, by authority of Public Law 87 - 703 , 
the Food and Agriculture Act of 1962 , gives technical and financial 
help to local groups in conserving and developing natural resources. 
Also, it helps project sponsors seek funds and services from other 
federal agencies and from state and local sources. The Soil Conser¬ 
vation Service has leadership for the USDA in this program. 

Resource Conservation and Development (RC&D) projects usually include 
more than one county. Each area should be large enough to include the 
resource developments needed to meet project objectives but small 
enough for effective local leadership to prepare and carry out a 
project plan. Local people initiate and run them. Applications for 
a project are sent to the USDA through one or more legal sponsors -- 
a qualified local group such as a conservation district, a county 
governing body, a town, a local or state agency, or a public develop¬ 
ment corporation. 


122 









Each resource conservation and development project has its own unique 
goals, but typically they attempt to: 

1 . Develop land and water resources for agricultural, municipal, 
or industrial use and for recreation and wildlife. 

2 . Provide soil and water resource information for a variety of 
land and water uses including farming, ranching, recreation, 
housing, industry, and transportation. 

3 . Provide conservation measures for watershed protection and 
flood prevention. 

4 . Accelerate the soil survey where it complements project measures. 

5 . Reduce pollution of air and water. 

6. Speedup conservation work on individual farms, ranches, and 
other private holdings and on public land. 

7 . Improve and expand recreation facilities; promote historical 
and scenic attractions. 

8. Encourage existing industries to expand and new ones to locate 
in the area and thus create jobs; encourage industries to 
process products of the area. 

9 . Improve markets for crop, livestock, and forest products. 

Through a resource conservation and development project, technical 
services and funds could be made available to plan and install the 
remedial measures and to provide information services necessary for 
implementing the management guidelines. With the large area involved, 
at least two RC&D projects would probably be formed -- one covering the 
three Northern Basins and the other for the three Southern Basins. 


COOPERATIVE STATE AND FEDERAL FORESTRY PROGRAMS 


The cooperative state and federal forestry programs are designed to 
promote sound forest management, protection, and use on private forest 
land. They also help improve the quality of life in rural areas. The 
programs require a close federal-state relationship that allows the 
state complete administrative authority while assuring the proper 
expenditure'of federal funds. 

The Cooperative Fire Control Program allows the Forest Service to 
assist the state with funding and technical guidance to hold fire 
occurrence and damage to a low level. 

The total cost of this program in California in Fiscal Year 1971 was 
over $ 27 , 457,000 for the entire state; federal funds amounted to 


123 







$1,118,648 of this total. In the past several years the federal 
contribution has been about five percent of the total expenditure. 

Presently the program emphasizes increasing the effectiveness of fire 
control by strengthening coordinated air attack operations and 
dispatch, command, and control systems. 

The Cooperative Tree Nursery Program encourages private landowners to 
keep their forest land productive by providing forest tree seeds and 
seedlings at a reasonable cost. The seedlings are raised at three 
state nurseries. This program, authorized by Section 4 of the Clarke- 
McNary Act, allows the federal government to contribute up to 50 per¬ 
cent of the net operational cost. In fiscal year 1971? the cost of 
operating these nurseries were shared as follows: 

Federal contribution $12,000 

State contribution 71?000 

Sales to private landowners 92,000 

Under the Cooperative Forest Management Act, Service Foresters, 
employed by the California Division of Forestry and partially financed 
from federal funds on a matching basis, are assigned to advise and 
assist small private timberland owners to help increase returns from 
timber resources and recreation development by applying multiple-use 
concepts. The local headquarters of the Service Foresters and the 
North Coastal Area served are as follows: 


Office 


Area Covered 


Santa Rosa 

Willits 

Fortuna 

Redding 


Sonoma and Lake Counties 
Mendocino County 
Del Norte, Humboldt, and Western 
Trinity Counties. 

Modoc, Shasta, Siskiyou, and Eastern 
Trinity Counties 


This program has been highly successful, but there is a need for con¬ 
siderably more services and program development than these four 
offices can provide. 


No statistics are available specifically for the study area, but for 
the entire State of California in fiscal year 1971? the federal share 
for the Cooperative Forest Management Program amounted to $86,208, 
while almost $148,000 was contributed by the state. About one-fourth 
of the private timberland in the state is within the study area. 

The area presently is served by the equivalent of two Service Foresters 
and has a need for three times as many. Service Foresters would be 
instrumental in accomplishing the forestry portions of the land treat¬ 
ment program on private lands. 


Under the General Forestry Assistance Program, the Forest Service pro¬ 
vides direct technical assistance to industrial foresters, forestry 
consultants, landowners holding over 5?000 timbered acres, other 


124 







federal agencies, and participating states. Through this program, the 
Worest Service provides technical forestry services that are unavailable 
from other state-federal cooperative programs. The assistance is direct 
ed toward developing, managing, and utilizing forest resources under 
multiple use principles so as to contribute to the Nation's economy, 
natural beauty, and resource wealth. Another objective is to correlate 
and interpret forest research findings for application of forested land. 

The Forest Pest Control Program is directed toward reducing insect and 
disease infestation on forest lands. The federal government may 
contribute up to 50 percent of the funds needed to stop infestations 
on non-federal lands. The program also maintains surveillance of the 
forest pest and disease problems on all lands. The following table 
shows how some of this money is spent throughout California: 

Federal Funds State Funds Total 

Blister Rust Control $20,000 $20,000 $40,000 

Other Pest Control Programs $15,000 $20,500 $35,500 

Timber production on non-federal commercial forest land can be aided by 
Title IV of the Agriculture Act (1956). Under this program, the Forest 
Service assists the State Forester in producing, distributing, and plant 
ing forest trees. Four seed orchards have been established in the 
state under this program. One of these, a Douglas-fir seed orchard, 
is located on the Jackson State Forest, near Fort Bragg. 

The Pacific Southwest Forest and Range Experiment Station of the U.S. 
Forest Service seeks solutions for full development, use, and protection 
problems on forested lands and works closely with the State Forester 
and other agencies interested in forest management. 

The Forest Service also assists the states by providing specialized 
training and by helping to secure federal surplus equipment. 


NATIONAL FOREST DEVELOPMENT AND MULTIPLE USE PROGRAMS 


Approximately 7,247 square miles of this study area are within six 
national forests, and all but 46 square miles of this area is in the 
Northern Basins. 

Prior to the passage of the Multiple Use--Sustained Yield Act on June 2, 
i 960 , national forests were managed under several federal statutes, the 
principal of which was the Organic Act of June 4, 1897 , as amended. The 
various statutes were implemented or supported by regulations and 
policies promulgated by the Secretary of Agriculture and the Forest 
Service. 

Although the principles and concepts of multiple-use management were 
developed before the passage of the Multiple Use--Sustained Yield Act, 


125 













it provided a congressional mandate for this type of management. Under 
this law, the Forest Service is directed to administer the national 
forests for outdoor recreation, range, timber, watershed, and wildlife 
and fish purposes. Multiple-use management guides have been prepared by 
each Forest Service Region and Subregion. In the guide for the Northern 
California Subregion, six broad management zones -- the Crest, Front, 
General Forest, Travel Influence, Water Influence, and Special Zones -- 
are delineated, and general management directions are provided for each. 

Using the principles outlined in these guides, multiple-use plans that 
provide broad management direction have been developed for each Ranger 
District. Within the framework of the multiple-use plans, functional 
plans are written to cover the development and use of each resource and 
to provide day-to-day management guidance. 

The following is an assessment of the ability of Forest Service to 
accomplish that portion of the recommended land treatment program that 
involves the national forests. The Forest Service has adequate legal 
authority and technical expertise to install the programs within the 
framework of its regular management and development. Generally, the 
only real lack is funding and, in some cases, setting of priorities. 

About 42 percent of the program for converting grassland to timber and 
about 25 percent of the one for converting brushland to timber is 
designed for national forest land. These involve about 40 and 35 square 
miles, respectively. Reforestation of this type, in the past few years, 
has totalled about six square miles per year on national forests. At 
that rate, it would take about 13 years to complete the recommended 
program. 

All of the recommended remedial road program involves national forest 
roads. Rehabilitation of these roads is estimated to cost over $62 
million, with an additional annual maintenance cost of $4.5 million. 

Funds presently allotted in the four national forests allow for little 
or no rehabilitation. Maintenance allocations average about $130.00 
per mile of road,,while the program calls for a maintenance expenditure 
of about $700 per mile. 

It is difficult to ascertain precise deficits in the funds allocated to 
do an adequate road rehabilitation and maintenance job. Final decisions 
must be made based upon a detailed study of the individual roads involved. 
However, it seems certain that present funds are inadequate and that 
these Forest Service roads will continue to yield sediment for many 
years to come if funding is not increased. 

Many of the management guidelines for logging, grazing, wildfire, 
recreation, game habitat management, and road construction are standard 
procedure in national forests. When failures in accomplishment occur, 
they are often tied to lack of funding or staffing, unforeseen events, 
pressures from outside groups, or lack of control of the resources. 


126 





OTHER ACTIONS NEEDED 


The total cost of the proposed remedial measures is about $90,109,000 
and would amount to $4,869,500 annually for the 20-year installation 
period. The previous chapter "Opportunities for Development Through 
USDA Programs" indicates that these programs, under present policy, 
could probably provide about $743,000 annually, which is about l6 per¬ 
cent of the amount needed to install the recommended remedial measures. 
Under accelerated conditions, about $1,063,000 could possible be fur¬ 
nished, which is about 24 percent of the amount needed. New legislation 
and programs or changes in present programs will be required to complete 
the full land treatment program. 


CHANGES NEEDED IN USDA PROGRAMS 


Most of the recommended land treatment program could be accomplished 
with the following changes in USDA programs: 

1. The land treatment program on federal lands can be accelerated 
by increasing the appropriations to the administering agencies; 
on privately owned lands, the programs could also be accelerated 
by providing adequate funds to each agency involved to cover the 
federal cost-share. To assure continued acceleration, appro¬ 
priations should be specifically designated for the land treat¬ 
ment program in these basins. 

2. To coordinate the USDA programs on privately owned lands, the 
Secretary of Agriculture should designate an individual or 
agency to provide leadership at the local level. This would 
accomplish the program in an efficient manner and prevent 
duplication of effort by the several agencies administering 
the USDA programs. 

3. The federal cost-share for installing the proposed remedial 
measures on privately owned grasslands should be increased 
from the present 50 percent to 80 or 90 percent. It should 
be raised to 100 percent for those measures to be applied on 
severely eroded grasslands since livestock would be excluded 
and the land would yield little or no future income. The 
increased cost-sharing for the proposed measures would increase 
federal costs about $3,000,000. These increases would provide 

a greater incentive for landowners and operators to participate. 
The federal cost-share should be increased on these lands 
because overgrazing has occurred for more than a century and 
often is not primarily the fault of the present landowners, 
and it is in the national interest to protect the scenic beauty 
and natural resources of this area. The present federal cost- 
share for remedial measures on other privately owned lands is 
probably adequate because the major benefits accrue to the land- 
owner in the form of increased production. Interest-free loans, 


127 







deferred payment of loans, and safeguards for continued 
maintenance or retirement should also be considered. 

4. A local association, such as a range improvement district or 
an association of resource conservation districts, should be 
formed to represent the landowners and provide the overall 
leadership for the land treatment program on private lands. 
Direct local participation would provide better opportunities 
for cooperation between federal agencies and landowners and 
for successful completion of the land treatment program. In 
any association formed, ranchers should be well represented 
since their interests are most deeply involved. 

5. Landowners of severely eroded private grasslands should be 
compensated for excluding livestock from these areas. If they 
are remunerated for property taxes, more landowners would 
participate in this portion of the program. Once the treatment 
programs are installed, the stabilizing effects should not be 
allowed to degrade by a return of improper use. Adequate 
maintenance and usage must be assured by long-term agreement. 


NEW PROGRAMS OR LEGISLATION NEEDED 


New USDA programs or legislation would be another way to accomplish 
more of the land treatment program on privately owned lands. The 
following ideas might provide a framework for developing a new USDA 
program: 

1. Formulate a regional program to develop and protect large 
regions, such as the North Coastal Area of California. Problems 
in flood control, fish and wildlife, recreation, and urban 
development would be considered in addition to those of 
agriculture and forestry. A regional agency under state and 
local leadership would be established to develop and coordinate 
the activities of the local people and the cooperating state 
and federal agencies. This agency and its cooperators would 
formulate a coordinated plan to develop and protect the 
resources of the area, making use of private resources and 
existing state and federal programs. Congress would appro¬ 
priate the necessary federal money, and the state would con¬ 
tribute funds to cover its share. Each of the cooperating 
agencies would be assigned responsibility for certain functions 
of the plan and would be given funds by the regional agency to 
implement their responsibilities. Prior to starting work, 
detailed work plans would have to be prepared for each function 
or phase of work. 

2. Form a council of USDA agencies to provide the overall leader¬ 
ship and to coordinate the activities of its agricultural and 
forestry programs. The council would cooperate with local 
associations or agencies to establish the policies and goals 


128 








of the land treatment program on private lands. It would 
assign the responsibilities for various functions to the 
appropriate USDA agency and would allocate the necessary funds 
to carry out these functions. 

3. Provide a specifically funded program similar to that for the 
Great Plains Area that would provide for federal-local sharing 
of the land treatment program costs on private lands in the 
North Coastal Area. A local association cooperating with the 
USDA agency designated to administer the program would estab¬ 
lish the policy and goals. A treatment plan with specific 
time limits would be developed for each property by the owner 
and the two groups. Prior to starting the work, a contract 
between the owner, the local association, and the USDA agencies 
would be signed, assuring that the necessary amount of federal 
funds would be made available to landowners during the agree¬ 
ment period. 

The present USDA programs with proposed changes or the recommended and 
new programs could accomplish most of the land treatment program. 

Since there are always a few individuals that will not participate, 
voluntary programs like these cannot be entirely successful, regardless 
of the incentives provided. To fully accomplish the objectives of the 
land treatment program, restrictive legislation would be necessary, 
although this approach may be politically unacceptable. Some possible 
actions uo uld be to: 

1. Enact state or local laws requiring landowners to protect the 
soil and vegetal resources on their land, with stiff penalities 
for failure to comply with the laws. 

2. Purchase the land or property rights from the present owners, 
under condemnation proceedings if necessary, and resell or 
lease them with appropriate controls on their development and 
use. 


129 




































ADDENDUM 


SPECIAL SEDIMENT STUDIES 


Two special sediment studies were made to check the soundness of field 
estimates of sediment yield. One consisted of measuring sediment 
deposition in eight reservoirs in the Southern Basins, and the other 
consisted of analyzing and interpreting suspended sediment data from 
seven gaging stations in the Russian River Basin and 11 in the Klamath 
River Basin. The results of these two studies serve as checks on the 
field estimates of sediment yield. 

RESERVOIR SEDIMENT SURVEYS 

In the Southern Basins, sediment surveys were made on eight reservoirs 
-- McGuire, Lazy Creek, M.S. Wilson, Ridgewood (Walker Ranch), Wood, 
Frediani, Hill, and Trentadue. The surveys were made between 1965 
and 1967? and the pertinent data are shown in the table on the next 
page. A map showing the location of the reservoirs and suspended 
sediment gaging stations is on the page following the table. 

Procedures 


The reservoirs were surveyed by the range method, which consists 
of laying out a system of representative cross sections and determin¬ 
ing water and sediment depths at regular intervals along them. Water 
depths were measured with a lead weight and surveyor's tape, and the 
thickness of sediment deposits were measured with a sampling spud. 

Sediment samples were collected in six reservoirs, and the dry unit 
weights were determined. The average dry unit weight for each reservoir 
was weighted according to the volume of sediment represented by each 
sample. In the other two reservoirs, the dry unit weight was estimated 
by comparison with the sampled reservoirs. 

Trap efficiencies of the reservoirs were obtained from a graph develop¬ 
ed by Brune.i/ In this graph, trap efficiency is plotted against a 
ratio of reservoir capacity to average annual inflow, and the results 
are shown in the table as Item 7* These efficiencies were used to 
determine the total sediment yielded by the watershed (item 9)* 

Field estimates of sediment yield by sources were made in the water¬ 
sheds above the lake using the procedures described in the chapter 
"Sediment Yield Studies and Survey Procedures." Comparisons of the 
results of the reservoir surveys and the field estimates are shown 
in Item 13 in the table. 


Gunner H. Brune, "Trap Efficiency of Reservoirs." American Geo¬ 
physical Union Transactions , Vol. 34, No. 3, PP* 407-4l8. (1964). 


130 











Reservoir Sedimentation Summary 


X 

<r 


x r- 
x m 


m x> 

X) r-4 


CN| ~ 

O 

X o 


X) 

o 




o 

X o 


• o 

X H 


D 

00 

< 


00 

cfl 

c 

CO 

u 

a 


•t-i E 
C *r-( 
3 *D 
<D 
05 
J-* 

Q 


0 ) 00 
^ E 


T) d) 
d) X 
05 05 
J- 

—< 0) 

CO ±-> 

3 CO 

C 5 

c 

< 


— E 

0) QJ 


0) 0) 

E u 
CO 
T3 


— E 

d) cu 


"O 05 
—< d) 
O 

T3 


C cm 
d) w 

E 

T3 
T3 d) 
d) x 

05 05 

U 

—« dJ 

cO ■*-» 
3 cO 
C 5 
C 
< 


c 

o ^ 

CO O' 

J- E 

C w 

c. —• 
E 
C 
U 


^1 ^1 


131 


Gunner H. Brune, "Trap Efficiency of Reservoirs", American Geophysical Union Transac tions, Vol. 34, No. 3, pp. 407-418, (1964). 























Survey crew conducting a sediment survey of Walker Lake> 
Mendocino County. scs photo 

Findings 


The results of these studies indicate that the field procedures used 
to estimate sediment yield are reasonable. In four of the reservoirs, 
the results varied by less than 20 percent, and in three others the 
difference was within 35 percent. 


SUSPENDED SEDIMENT DATA 


AVAILABLE DATA 

Suspended sediment data is published annually by the U.S. Geological 
Survey^/ for l8 stations in the basins. The maps on the follow¬ 
ing pages show the location of these suspended sediment gaging 
stations some of which began operating in October 1958. Streamflow 


USDI Geological Survey, Quality of Surface Waters of the United 
States, Parts 9~lb , Water Supply Paper 19^5- (Washington, D.C., 

U.S. Government Printing Office, annually from 1957-1962). 

Water Resources Data for California, Part 2. Water Quality Records . 

(Menlo Park, California, annually since 1963 ). 


132 












data, published annually by USGS:k/ and flow duration data for Califor¬ 
nia streams,.!/ available through 1959 ? were used extensively in the 
analyses. 

PROCEDURES 

Suspended sediment samples are taken periodically at 16 stations in the 
basins, and daily at two stations -- South Fork Trinity at Salyer and 
Trinity at Hoopa. Periodic sediment sample data were converted to mean 
annual sediment yields, using flow duration curves and other methods 
described by Searcy3/ and Miller. z/ The table "Mean Annual Sediment 
Discharge for the Period 1940-1965" on the next page presents the results 
of this study. 

To determine the total sediment load at each gaging station, bedload, 
estimated to be 10 percent of the suspended sediment, was added to the 
suspended sediment, using methods described by Sheppard ( 1963 ) •'2J 

The volumes in the last two columns in the table were computed using 
two different unit weights. The next to the last column shows the 
total volume of sediment that is eroded from the watershed each year, 
assuming an average in-place soil density of 92 pounds per cubic foot. 


1/USDI Geological Survey, Quality of Surface Waters of the United 
States, Parts 9~l4 , Water Supply Paper 1945. (Washington, D.C.. 
U.S. Government Printing Office, annually from 1957-1962). 


W^ter Resources Data for California, Part 2. Water Quality Records. 

(Menlo Park, California, annually since 1963 ). 

W inchell Smith and Charles F. Hains, Flow-Duration and High- and 
Low-Flow Tables for California Streams , Open File Report (Menlo Park, 
California, USDI Geological Survey, 1961 ). 600 pp. 


—/james K. Searcy, Manual of Hydrology: Part 2. Low-Flow Techniques, 
Flow Duration Curves , U.S. Geological Survey Water Supply Paper 
1542-A. (Washington, D.C., U.S. Government Printing Office, i 960 ). 
33 PP- 


Carl R. Miller, Analysis of Flow-Duration, Sediment-Rating Curve 
Method of Computing Sediment Yield ~ (Denver, Colorado, USDI Bureau 
of Reclamation Hydrology Branch, April 1951). 55 pp. 


John R. Sheppard, "Methods and Their Suitability for Determining Total 
Sediment Quantities." Proceedings of the Federal Inter-Agency Sedi¬ 
mentation Conference, 1963 ; USDA Miscellaneous Publication No. 970? 
pp. 272-287. (Washington, D.C., U.S. Government Printing Office, 

June 1965 ). 


133 














BASINS 

A CLEAR LAKE 
B“C RUSSIAN RIVER 
DEF MENDOCINO COASTAL 


SUB-BASINS 

B SOUTHERN RUSSIAN E CENTRAL MENOOCINO 

C NORTHERN RUSSIAN 
D SOUTHERN MENDOCIN 


F MATTOLE RIVER 


Mimber 

4610 

4615 

4630 

4632 

4639 

4652 


Suspended Sediment Gages 


Name 
r Ukiah 

c Fork Russian R. near Calpella 
r Cloverdale 
Big Sulfur Cr. near Cloverdale 
Maacama Cr. near Kellogg 
Dry Cr. near Geyserville 


Reservoir Surveys 
Tributary Watershed 
/. McGuire 

2 . Ridgewood (Walker) 

3 . Lazy Creek 

4 . M.S. Wilson 

5 . Wood 

6 . Fredian i 

7 . Hill 

8 . Trentadue 




CLEAR LAKE 
BASIN 


SUSPENDED SEDIMENT GAGING STATIONS 
and 

RESERVOIR SEDIMENTATION SURVEYS 

SOUTHERN RIVER BASINS 

HUMBOLDT, LAKE, MENDOCINO, AND SONOMA COUNTIES, 
CALIFORNIA 

NOVEMBER 1971 


SCALE I 760,320 














I-ISVIZ-O-ZW 



SUSPENDED SEDIMENT 
GAGING STATIONS 

WEST HALF 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 


LEGEND 

■ River Basin Boundary 

A SUSPENDED SEDIMENT GAGE! 
5175 Shasta neor Yreka 
5195 Scott near Ft Jones 
5205 Klamath near Selad Volley 
52 30 Klamath ot Orleans 
5255 Trinity at Lewiston 
5258 Weaver Cr. near Douglas City 
5265 North Fk. Trinity at Helena 
5290 South Fk. Trinity near Solyer 
5300 Trinity ot Hoopo 
5305 Klamath near Klamath 
5325 Smith near Cresent City 
(No suspended sediment gages in east 
half of basin) 


NOVEMBER 1971 

















Mean Annual Sediment Discharge 
for the Period 1940-65 




Station 

Period of 

Record 

Drainage 

Suspended Sediment 

With Bedluad 

Volume in 

AcrFt/Yr. 

(Number) 

by Water Years!/ 
Water Sediment 

Area 

(Sq.Miles) 

Per Sq.Mile 
(Ton6/Yr.) 

To t a 1 
(Tons/Yr.) 

est at 107. 

(Tons/Yr.) 

Lost from 
Wa tershed 

Deposits in 
Reservoir 




Russian River Basin 





Russian near 

Ukiah (4610) 

1953-65 

1969 - 65 

99.7 

1600 

160,000 

176.000 

90 

no 

E.Fork Russian 
nr.Calpella (4615) 

1992-65 

1969-65 

93 

800 

73,8002 / 

81,000 

90 

50 

Russian nr.Clover- 
dale (4630) 

1952-65 

1969-65 

502 

1300 

653,000 

718,000 

360 

450 

Big Sulphur Cr. 1958-65 

nr.Cloverdale( 4632) 

1969 - 65 

82.3 

2800 

230,000 

253,000 

125 

160 

Maacama Cr. nr. 
Kellogg (4639) 

1961-66 

1969-65 

93.2 

600 

26,000 

27,000 

15 

17 

Dry Cr.nr.Geyser- 
ville (9652) 

1960 - 65 

1969-65 

162 

9300 

697,000 

767,000 

380 

980 

Potter Valley 
Tailrace nr 

Potter V.(4710) 

1909-65 

1969-65 

b. 1 - 3,200 3,200 

Klamath, Trinity, Smith River Basina 



Shasta nr.Yreka 
(5175) 

1996-65 

1956 

1959-62 

796 

25 

20,000 

22,000 

11 

19 

Scott nr.Fort 

Jones (5195) 

1992-65 

1956^ 

653 

800 


- 

“ 

‘ 

Klamath nr.Selad V 
(5205) 

1960 - 65 

1956 6 -' 

6,930 

90 

- 

* 

* 

* 

Klamath nr.Somesbar 1942-65 
(5230) 

1956*' 

8,500 

200 

- 


* 

“ 

Trinity nr.Lewis¬ 
ton (5255) 

l? 40 - 6 ol / 

1956-60 

728 

3 00 

218,000 

290,000 

120 

151 

Weaver Cr.nr.Doug¬ 
las Clty(5258) 

1959-65 

1963-65 

4a 

500 

29,000 

26,000 

13 

16 

N.Fk.Trinity nr. 
Helena (5265) 

1958-65 

1963-65 

151 

200 

30,000 

33,000 

16 

21 

S.Fk.Trinity nr 
Salyer (5290) 

1951-65 

1956 

1958-65 

898 

1,500 

1,397,000 

1,982,000 

790 

930 

Trinity nr.Hoopa 
(5300) 

1990-65 

1957-65 

2,865 

1,700 

9,870,500 

5,358,000 

2,680 

3,370 

Klamath nr.Klamath 
(5305) 

1951-65 

1956^ / 

12,100 

1,000 

* 

" 

* 

“ 

Smith nr.Crescent 
City (5325) 

1990-65 

1956^' 

609 

300 


“ 

* 

* 


1 / A water year la the 12-month period October i through September 30. The year la dealgnated by the calendar 
year In which It ends and includes the first nine months ot that year. 

2/ Volumes are based on estimated dry unit weight (bulk density) of 2000 Tona/Acre-Ft.(92 lbs./cu.ft.) for 

“ .oil in place. The estimated weight of 1590 Tons/Acre-Ft.(73 Ibs./cu.ft.) reflects the effect of bulking 
such aa would be expected if the sediment were deposited In a storage reservoir. 

3/ Rate Is net for watershed after subtracting 3200 Tons per year estimated to be contributed by Eel River 
water diverted through the Potter Valley tailrace. 

U! Vater Is diverted from Eel River above Van Arsdalc Dam. After passing through powerhouse, part of It Is 
used for Irrigation in Potter Valley and remainder flows into East Fork Russian River. Sediment Is essen¬ 
tially all suspended. 

5/ Unregulated flows prior to construction of Lewiston Dam. 

6/ One year of sediment record. Record Is very scanty and computed yields should be considered only as estl- 

” mates for the one year of record shown. 


13k 




















This density is a weighted average of soil samples taken by Gardner 
( 1963 )i/ and by McLaughlin and Harradine ( 1965 ).^/ Field estimates 
of sediment yield from all sources can be compared with the figures 
shown in this column. 

The last column presents the annual sediment rate that could be expected 
if a reservoir were constructed in the vicinity of a particular gaging 
station. The figure reflects the effect of bulking, which is the 
tendency of sediment to occupy more space in a reservoir than it does 
in-place on the watershed. Sediment deposition in reservoirs would 
probably have characteristics similar to those found in a survey of Lake 
Pillsbury in 1959* The U.S. Geological Survey found that the average 
dry density of sediment was 1,590 tons per acre-foot (73 pounds per 
cubic foot),^/ which represents a bulking increase of 26 percent. 


SOILS DATA 


Soil characteristics and interpretations presented in this section are 
based on information taken from published surveys, except in national 
forests, where only limited standard surveys have been made. .A general¬ 
ized soil map was developed for the national forest lands, using aerial 
photos, geology maps, and other available data. About 200 soil series, 
each with several phases, were combined into 92 soil associations for 
this study. 

The table "Soil Characteristics, Qualities, and Interpretive Groupings" 
appears on the following pages and shows the main components of the soil 
associations and some of their features. An estimate of the areal pro¬ 
portion of the major soils and of the others included in each association 


—/Robert A. Gardner and others, Wildland Soils and Associated Vegetation 
of Mendocino County, California ! (Sacramento; Resources Agency of 
California, Cooperative Soil-Vegetation Survey Project, 1964). 113 pp. 

—4jam.es McLaughlin and Frank Harradine, Soils of Western Humboldt County, 
California . (Department of Soils and Plant Nutrition, University of 
California, Davis, in cooperation with the County of Humboldt, 

November 1965 ). 85 pp. 


G. Porterfield and C.A. Dunnam, Sedimentation of Lake Pillsbury; Lake 
County, California, U.S. Geological Survey Water-Supply Paper 1619-EE. 
(Washington, D.C., U.S. Government Printing Office, 1964). 46 pp. 


135 
















13 6 


2/ Indicates rating used on Hydrologic Soil Groups Map 


























































































UO 

o 

z 

Q_ 

3 

o 

CXL 

o 

LU 

> 


LU 

CYl 

Q_ 


z 

Q 

z 

< 

uo 

LU 


< 

3 

o 


LO 


oo 

O' 

LU 

h- 

u 

< 

x 

u 


O 

IS) 


^ h § 

| ? | i? 


X 

u 


£ 




-3 

X 


g 

o 

u 


'z 

W3 

d 

o 

CO 


J 

u 

o 

u 


J 

o 

0 

a 


1 

1 



it 

^ V!> 


o 


CO 


- 


CO 


Q 



CJ 


“ 


« 


1 

1 


l! 

iff 

sy 


O' 

o 

ki 


o 


O 


O 


o 


O 

o 


o 


o 


1 

1 


5 ^ § 
S: & s 
ii ^ ^ 


s 

o 

o 


o 

<r> 

o 

o 


g 

o 

O 


O 

v* 

o 

o 


o 

o 


o 

o 

o 

cn 

o 


o 

X 

o 

o 


o 

vO 

o 

o 


1 

1 


TT 

11 

HJ ^ 


>» J= 

if 5 


a 

TJ 

O 


§ 

x 


u "m 

> X 


OO 

X 


>. X 

Li O0 
il ^ 

> X 

>> X 

Li 00 

> X 


X 

OO 

X 


>> X 

fl 


>. X 

Li OO 
fl iH 

> X 

>. X 

Li 00 

> X 


8 

0 x 

§ Ij 



3 

o 


>. 

S -T3 

XJ CL 

O 03 

X u 


S 

2 

2 -a 

X3 Q. 

i 2 


>> 

X3 a 
o o) 

X ^ 


?o 

0) 

03 3 

-a o 
z 7)" 


5 

03 73 

O 03 

P*-> 

03 3 

T) O 

z 


03 3 

T3 0 
° "w 


fl 3 
■a o 

O -i 


1 

1 


1 5 
i 3 


e ? 
p*. o - 

0) c 

u u c 
<a o c 

o v x 
X 3 3 


_ 


3 


3 


3 


« > 

3 w 

E o 

O >< 

3 


3 


3 


1 

1 


§ 

L 


0 

CL 

O 

e cj d 

<0 -H 

a <a c 

Z X L 


03 -X 

C U 

O 03 

s ?, 

X3 CI3 

C L. 
fl ^ 


O 03 

S ?, 

XJ 03 

C L> 
fl o 


03 

0) _* 
c o 

O 03 
w 3 
w 

T3 03 

« O 


c 

c 


O o3 

S | 

ai J«; 

O 03 

w 3 
w >. 

XI 03 

fl O 


O 

•o w 

03 3 
fl O 

O 0) 

CL 00 

O 

E o 

Z X 


J2 

o 

Li 

M O 

O fl 

X C 

CL OO 

Li i-l 

O 

E cj 

fl fl 

Z X 





§! 

I 

1 


s 

>, -H 

X3 03 
— .X 

£ «• 


6 

3 

•U -H 

X 0J 


•H XJ 

T3 i-l 

Z o) 


E 

3 

•H TD 

T3 H 

Z 03 


Li 

3 


C 3 

o -a 

E 

T3 
■a -jh 


E 

T3 -i-l 

Z fl 


E 

•a -h 

Z fl 


w> 

o 

E 

oo 

fl 

14-1 

O 

Li 

5 

I 

5 


03 

CJ 


e 

o 


e 

03 

O 


E 

03 

O 


>1 c 
-■ C 

> > 
Li 03 0 

> 00 C 


> E 

03 a3 

O ° 

E 

>, 03 
— O 

03 

> 

fl fl 


E 

03 

_i o 

> ^ 

fl fl 


E 

pn « 
o 

> >> 

a a 

Li —• 

O O 


X) 

c 

fl 

C 

fl 

fl 

i-l 

«a = 


1 

{* 

1 

•o 

i 

£ 

VI 

5 

¥ 


0) 

3 


03 (J ‘ 


E 

■H -D 

XJ -w 

X o3 


E 

3 

T3 -H 

Z 03 


oo -o 


•w "O 

X> -h 

Z 03 

>, 

X 

oo -v 

CO fl 


E 

3 

-D -H 


E 

3 

T3 -H 

Z fl 


o 

o 

03 

-i L 

O oi 
01 0 

L-l 0 

O MM 

oi : 


1 

R 


B 

o 

O 


E 

03 

O 

X 


E 

O 

■J 


03 

O 


>> 

>. > E 
L. 03 0 
03 U 0 
> 00 — 


>L 

03 

> E 

03 03 

> E 

O -3 


fl E 
> fl 

03 O 


>. 

03 

> E 
fl fl 


o 

CL 

XI 

X) 

z 

oi -a 
O fl 
CL 0 
03 O 
X) Q 
X 

•o fl 

X XJ 

Z fl| 


i 

I 5 

5e 


<r 








2 





2 


2 


1 

1 


& 

i 

5 

5. 


g 




> 


> 


> 


C^I^S 

> 

> 


> 


S 


§ 

> 


i* Vj 
$ 

r* 

Ni 

§ 

1 






















t | 

$cj 

H 

* § 


o o 

p- co 


o o 


o o 

CO CM 


o o 


O O 
r-' co 


O 

O O 
<r -i 


O O 


o o 


o 

X 

o o 


b £ 

1 | 

m 

to ^ U 

$ 1 

*n. J 

if 

fl 

<\ fl 

CL 

— 1 o 

> o 
-X 

O m 

> 

1 o' 

o g 

< i 

CL 

c 

-t o 

"oo o 

3 U 

5 O 

c 

X 

Sf 

3 

c| 

•2 « 

Is 
s g 

< CL 

38 

X O 

00 *j 

3 

is s 

c 

00 

1 

,1 

II 

< Q. 

c in 
-h r-' 

!c o 
oo u 

3 

X. 

oo 

3 

3 

if 

< Q. 

a) o 

c o 

C u 

X 

i 

o a. 

o c 

O Lj 

O CL 
i 

c 

03 O 

E *-> 

>. 

22 

E 

1 

. 

o 

o 

o 

o 

o 

cn 

i 

•w S 

O CL 

o o 

< “ 

Li C 

E C3 

O 03 

O Li 

X CL 

s 

o 

o 

ca 

2 

o 

c 

U CL 

o o 

M W 

Li C 
fl fl 

S U 

O 03 
(i a 

E 

o 

o 

X 

c 

•o fl 

1-1 CL 

•a r' 
c 

3 2 

■o O' 

—1 c 
o 

P* i-l CO 
3 CJ 0) 
^ O CL 
—1 M O 
O co -i 
CJ < oi 

XI 

c 

03 

03 

> 

3 

O 

CJ 

XJ 

X 

c 

3 


81 

lo 

o 


- 


2 


co 


2 


vO 





CD 









a 

I 


137 


2/ Indicates rat-JLtffc used on General Land Capability Map. Or Hydrologic Soil Groups 













































































































uo 

o 

z 

Q_ 

Z> 

O 

O' 

o 

LU 

> 

I— 
LU 
O' 
CL, 
O' 
LU 
I— 

z 

Q 

z 

< 

LQ 

LU 


< 

z> 


O 


on 

U 

i— 
LQ 

LU 

h- 

U 

2 

< 

X 

u 


O 

LO 


Q "5 

» 5 S S? S 
1 3 $ 


X 


ru 

CO 

)-< 

0 

2 

a 


g 

x 

cj 





5 ? 



2 
•> CO 

2 

O M 

O 

(Xi Oj 

O CO 

1 


X 

0 

X 

0 

g 


Vj 

* 

§ * 

^ VD 


- 


m| 

< 

l 


ea 

DO 


cq 

CQ 


« 

ob 


< 

< 


CM| 

CJ 

Q 


Ml 


O 


m 

O 

1 


0 

0 

0 


0 

O 

O 

O 


O 

X 

0 

0 

X 


1 

1 


O' 

0 

> 

O 

O 

DO 


1 * I 

j? § ^ 


00 

<r 

0 

t 5 


* 

p 

1 


♦ 

0 

vO 

0 


4 

0 

0 

4 

O 

vO 


O 

O 

O 

“ 

O 

X 

0 

0 


1 

0 

X 

0 

0 


£> 

O 

X 


| | 

| 1 


oo 

rn 


g 

§ 

s 

l 


3 

O 

3 

0 

X 


3 

3 

S 


3 

O 

X 

3 

O 

X 


X 
u 00 

> X 

>> X 
* cj 00 

> X 


g 

3 

X 


T1 

§ 1 
$ S 

1 1 

10 * 


>> 

a 

u xj 

0 Q. 

10 a 

X p 


0 

Q. 

p 

p 

> 

1 

.. 

a 

•0 

X 

3 

0 

a a 

a a 

a a 
-a xj 

0 0 
x e 


a 

0 

X 

O ^ 

a a 

a a 3 

■DUO 

0 0-4 

x a a 


O ^ 

a a 

a a 

a a 3 

U U O 
0 0-4 

x a a 

•O 

X 


1 

1 


O 

a 

a 3 

XJ 0 

0 -■ 
s: a 

3 

O 

0 « 

1 & 

CO > 



! 3 

1 a 


* 


>> 

> 

s 

1 

l 


2 

ft 

>N 

P 2 

0 a 

—> a) —< 
-* -0 -> 
a 0 a 
2 a 2 


2 

-< O U 

M C 

0 

a m 1 

■a ■—4 a 

0 -4 JZ 
x a 3 
3 


>* 

w 

XJ — 

0 a 

X 3 

2 


1 

1 


a 

x ^ 

3 -4 

a 0 

0 0 

CO Q. 

O 

O 


ki 

1 

§ 

ijNj 


c 

0 

rxj 

c 





a 

! 

s 

*4 

a 

3 

3 a 

3 

-■ O 

< p 

J2 

a 2 

0 

a 
a xj 

3 c 

> a 

3 --4 
—1 XJ 

< a 


•0 -> 
c a 
a > 

u 

■a qo 
a 

CM C 

•m a 

a a 
!-■ a 

M ^0 

a 

a 

0 


a 

0 

X) —< 

--4 > 

M 00 

J-J c 

> 

u 

O 


a 

0 

X 

3 


>N 

a 

>, 

CJ 


1 

I 

K 


00 

c 

0 

s 3 

0 

>, a 

<j) 


■0 

c 

a 

6 

3 

c 

3 


u 

3 

a e 

3 

2 


3 

a 

"a 0 


>» 

00 

c 

0 X) 
iJ -M 

?>s 

OO 

C 

>. O u 


00 

0 

a 

XJ 

c 

3 

xj 3 

X O 

XJ 


a 

3 

M XJ 
"a "u 

>> 

xj C 

a a 

XI JiC 

0 -4 

s: a 

m 

l 


a 

a 

:>» 0 

a ^ 

> XJ 

a c 
p a 

0 a 


I 

O 

O 0 

C 

0 

0 

3 


XJ >> —- 
a x> -w 
•h c a 

a 

a a a 

P C CC 
XJ t 4 ol 
a ai y 

>% 

4 j a 
—■ a 
•H O 

CO —1 


a 

a 

0 


a 

0 

a 

0 


a 

u 

a 

X 

c a 

■—1 > 

0 

>N 

- a 
a a 
xj a 

M P 

3 xj 

00 


>s 

a 

>% 

c 

CO 

a 


1 

5S 

I 

•o 

f 

1 


00 

c 

0 xj 

tn a 


a 

c 

0 

3 

a 

x 

a 

X 

Sn 

O 


3 

25 

a 

3 ' 

2 


3 

z 

?*■> 

JO 

qo xi 


X 

00 xi 

00 

c 

^ 0 XJ 

a M 0 
> a a 


XJ 

>s 

a 

>. 3 

U O 

a p 

> X 

a 00 

O C 


a 

•H XJ 

XJ -H 

z a 

00 XJ 

co a 


I 

5 


a 

0 

•0 


a c 

a a 

a a 

0 0 

5 

•a m 

C 4 J 

•0 a 
c > 
a a 
co 3 


a 

a 

0 

XI, 

>% 

u a 

3 0 


a 

0 

e 

0 


a 

0 

a 

a 

0 

j 


00 a 

► 0 ) 
c 

XJ c 
c a 

XJ *o 

a c 

> 3 

3 a* 

< »M 


a 

0 

a 

CJ 


sis 

3§$ 


-a- 



<r 


<r 

<r 


<r 

<r 


•sf 

a- 


1 

<r m 


•0 

<r 


£ 

I 

§ 



s 


£ 

> 

> 











3 

CN |||—1 

3 

> 





CV 0 

1 $ 

'sj 

1 

I 







Sia 

- 


3 

•—1 

3 


5 

*-• 





£ 

3 


t 1 

I s. | 

% i 


0.0 
r« on 


0 

O 


0 

0 0 
<r - 


0 

x> 

O O 


0 

a- 

0 0 
a- <n 


O 

-J 

O O 
<r <n 


0 

m 

5 ° 


; 1 | 

* 1 
m 

<*> ^ L> 

J| 

O 

O 

X 

O .« 

O O . 

a a 
< 

u c 

0 0 
•O 0 

2 Q- 

a - 
-o 

3 

c 

X & 
a °* 

US 
a S’ , 

a 0 

O - 
W C 

■is- 

ij. 

. -<j a 
a 0 q 

3 S - 

Q < a 

' 

•0 

s 

1 

„ 

1 

X 

i 

0 

c 

0 

a o. 

■H 0 

|" 

< c 

a u 

0 a 
a a 

t^CM 

O O 

O 

>■ O 

g. 

5 

a 

> 

0 

. 

0 

0 

>< 

a 

0 

1 

c 

0 

■h a 

0 Q. 

0 0 

a a 

a c 
a a 

3 0 

05 P 

a a. 

a O' 

•0 

c 0 

U XJ 

C »4 O 

V 

•o 

c 

a 

C*4 

3 

C 

a 

0 

u 

a 

Q. 

00 w* 

3 0 

X M 

u 0 
a 

M C 

w 0 

a m 

00a 
— 00 
u a 0 

U < a 

0 

00 

3 

X 

a 

XJ 

w 

c 

XI t4 

c a 
a a 

O' 

a 0 

> 

3 O 

< C 

1 O 

X M 

a a 

2 u a 
a 0 q 
> a O 
S -a a 

X 

e 

a 

> 

os 

XJ 

c 

> 

3 

< 

C 

0 

a 

0 a 
a o. 
a 0 

a 

J«S xj 

3 s 

a a 
a a 

CJ CM 

a 0 

0 

CJ 0 

a 

0 

a 

3 

CJ 



J i 

III 

CM 


s . 



O' 



O 



tn 

<n 



CO 



s 





138 


2^ Indicates ratipg used op General -Land Capqbiljty Map or Hydrologic So^J. Groups Map; 

















































































LT) 

o 

z 

Q_ 

Z 

o 

Cxi 

o 

LU 

> 

I— 

LU 

Cxi 

Q_ 

O' 

LU 

I— 

z 

Cl 

Z 

< 

oo 

LU 


< 

Z 

O 

OO 

U 

h- 

oo 

Cxi 

LU 

h- 

u 

< 

x 

u 


O 

os 


^ b § 

I 5 ! 3 


j 

o 

o 

d 

. 

o 


J 

o 

J 

□ 

CO 

r- 


J 

o 


J 

CJ 

o 

J 


La 

O 

^ d 


■-3 

U 

o 

s 

J 

CJ 


►J 

U 

O 

CJ 

O 

o 

s 

[ 

« 

* 

* 

■» $ 


<N| 

aa 



CN| 

U 

Q 


- 

- 


CQ 

QJ 


CJ 


a 

Cs 


CN| 

CJ 

Q 

o 

jj ^ ? 

11 S * 

^ *C 0 'i 


o 

o 

m 

4- 

O 


vO 

0 

o 


0 

o 


O' 

O 

cO 

O 

<r 


d> 

© 

&■ 


o 

PO 

o 



<J 

o 

1 

^ “N 

- £ 5 

tf 2^ c 

$ * £ 


o 

v£> 

2 

§ 

O 

CN 


o 

2 

S 

: 

: 


+ 

o 

£ 

'O 


O 

O 

O 

<r 

o 

v£5 

o 

o 


o 

o 

o 

m 


CN 

0 

o 

fN 

o 

CO 


o 

o 

0 

o 

1 

TT 

5 1 


3 

O 

3 

O 


« 

? 

o 

TJ 

O 

f 


3 
o 
—] 

3 

o 

-J 


La 

o 

e 

TJ 

O 


8 

J 


® 

■o 

0 

6 

to 

La 

© 

TJ 

0 


Ps X 

:La 00 

> X 

ps x: 

La 00 

> X 

1 

$ 

§ 

'■o 

£ 

§ 

I 


o PS 

l- la t 

TJ T) C 

s i > 

tj 

2 


3 

O 

i 

5 


La -a 

TJ CL 

O <0 

X La 

O Ps 

La La 

QJ QJ 3 
TJ TJ O 

o o-< 

SEW 


PS 

0) O Q 

to a 

La TJ L 
QJ A Q 
TJ CL TJ 

o to q 

S La g 

3 

O 

» 


Ps 

3 

•S, o 

§. W 


to 

La 

T3 

O 

s 

© 

TJ 

O 

s 


TJ 

1 

TJ 

CL 

1 

1 5 

i a 



- 

•s 

3-2 

1 I 

e o 

3) 2 


J= PS 

3 - 
aj u 

e o 
o o 

C/3 CL 

o 


3 

PS 

O to 

qj ”o "a 
3 E 3 


3 

PS « 

- 5 

AJ O 
to AJ 

•a —• 

O QJ 

S ? 


■i ^ 

3 tl 
s o 
o o 

CO CL 





3 

3 

1 

£ 

§ 

s 

>k 

i§f 

}*S 

’Si 


TJ 

c 

oo 

Ps e 

u © 

<u o 
> — 

u 

o 

c 

PS <0 

© Ps 

5 1 

La o 


C 

o 

■o 

c 

E 

3 

> 

3 

C 


E 

O 

O 

Ps 

to 


1 ' 
O 

t 

> 

o 

?s 

U 


e 

o 

S E 
o 

vs C 


i 

TJ 

La 

3 

tfl 

Ua 

to 3C 

XI (J 

o 

TJ La 

tU 3 

x: o 

AJ 41 

<0 c 

4J 00 

3 HA 


O 

Ps 

X 
' La 

TJ 

© 

La 

© 

X 

as 

3 

O 

PS 

X 

TJ 

La 

« 

& 


S 8 
1 I 

§ 

1 

Is 

:lj 


E 

TJ tA - 

x © 

PS 

§ 3 

C/j <0 


?s 

00 

O TJ 

Li -H 

V) <a 

Ps 

00 

O TJ 

La --a 

Si 8 


E 

3 

TJ -rA 

X aj 

Ps 

-C 

00 TJ 


oo 

c 

O T> 

E 

3 

■O -H 


PS 

00 TJ 


Ps 

OO TJ 

CO to 

Ps 

X 

00 TJ 


S 

3 

tA TJ 

TJ -A 

s © 

S' 

3 

aA TJ 

TJ rA 

X © 

a. 

3 

O 

£ 


B 

O 

>? 

* 

u 

E 

ps o 

4) > 

PS > TJ 
La © C 

> qo 03 


?s 

^ _ 

TJ B 

as O 

CO 

2 § 
c PS Q 

inj -o 

ECU 
0) aj x 


Ps 

Ps "O B 
La C to 
ii « a 
> w — 

B 

W 


6 

0 

PS 

CJ 

Ps 

Ifl 

>. 

TJ 

CO 


E 

o 


Ps 

s 

3s 

-A E 
-O as 
xs o 
.O J 

u 

E 

tO 

O 

Ps 


PS 

PS 

TJ E 

c© o 

PS 

> E 

O ° 

! 

La 

TJ 

C 

§ 

L 

L 

5 

a 

f 

| 


PS 

OO 

O TJ 

PS 

00 TJ 


O0 

c 

O TJ 
PS Li 

PS 

E 

X u 


E 

3 

TJ 

TJ •'A 

Z W 

E 

3 

tA TJ 

TJ -rA 

S tO 


E 

TJ 

TJ T4 

S « 

E 

3 TJ 

T) CJ 

S 


PS 

ss 

00 TJ 


PS 

X. 

00 TJ 

E 

3 

TJ 

TJ -H 

4) o 

S (0 


x: 

00 TJ 

CO © 

PS 

X 

00 TJ 

o 

$ 

£ 


PS 

© 

> B 
© © 
o >2 

Ps 

QJ PS 
> T) B 

O W ° 


E 

Ps 

TJ 

C 

E 

<d 

o 

Ps 

TJ 


C 

^ PS 

PS TJ E 

QJ <0 O 

CO 


E 

O 

E 

<0 


E 

0 


Ps 

— E 

w S 

3s X 

XI 

aO 

0 

V 

E 

O 

Ps 

JC 

o 

Oi 


PS 

© 

> E 
© © 

La O 

O -a 

> B 
© © 

H 0 

O -A 

3 

O 

Ps 

> 

ill 

^ ^ ^ 


<r 

<r 





<r 

<r 


<r 

<r 


<r 



« 





£ 

1 \ 
\ 3 

5 

1 $ 

t 

NJ 







3 










C'Jlw 

> 


> 

> 

> 

§ 

i 


s i. 

s 

£ 





^1 

3 

5 


^1 

,2 


3 








t | 

> s 

5 v 5 

i* « & 

* 5 


o 

o o 


o 

" 

O O 


O 

o o 


o 

o o 


o o 
r-' m 


o 

o c 


o 

o 

o c 

b ft 

c | 

5 ? 

•o ^ k) 

8 ? 

- | 

c 

o 

o a. 
wo 

< w 

oo c 

! g 

H CL 

o o 

C AJ 

cl o 

"o 

c 

CL 

00 

1 

H 

c 

o 

gf 
<" 

J* c 

i! 

o o 

o 

Z o 

o 

PS 

o 

o 

CO 

c 

o 

O CL 

W o 

< w 

2 C 

E O 
<0 La 

■ CL 

Is 

So 

•o 

0 

1 

s 

La 

O 

g 

N 

O 

<0 

O 

< S 

CL 

QJ O 

> AJ 

C O 
r. La 

O QJ 

as cl» 

<0 O' 

to o 

< o 

< 

> 

La 

c 

o 

o 

o 

g 

is 

a cl 
w ° 

< *° 

0 c 

to QJ 

Cl cl 

o 

CL 

C 

o 

-2 w 

O CL 
w O 

Ifl c 
s © 

O CJ 

(2 S 

i CL 

C O 

-L CO 

TJ 

-* O 

3 AJ 

cS O' 

oo 

c 

TJ 

3 

3 

® 

s 

o 

o 

c 

© 

CL 

TJ £ 

c 

as o 

J«J O 
cj ro 

O 

I c 

TJ O 

TJ **A 

P*Q © 

< HA W 

TJ © © 
La O Q 
aS ® O 

U < w 

TJ 

| 

-© 

Cl 

TJ 

TJ 

U 

TJ 

c 

© 

o 

QC 

§ 

J 

ll 

o 



r- 



CO 



O' 

m 





ro 



<r 

St 





139 


1/ P£AC£NT /M ( - ) 6/VS.S S/TSA/r Of OT7ASP SO//S /H TPS ASSOC/AT/OPS 

2 a^.es racing used on General Land Capability Map or Hydrologic Soil Groups Map 













































































































uo 

0 

z 

Q- 

3 

o 

o 

LU 

> 


LU 

CxC 

Cl. 

CsC 

LU 

I— 

z 

Q 

z 

< 

LD 

LU 


< 

3 

o 

uo 

U 

(— 

oo 

LU 

I— 

U 

2 

< 

X 

u 


O 

LT) 









l 


l 


. i4o 


// P£PC£NT W 6/f£S £*ravr Of OTP£P S&iS /A/ TP£ ASSOC/AT/OPS 

2/ Indicates rating used on General Land Capability Map or Hydrologic Soil Groups Map 














































































V PEPCEMT M C - ) SIXES EX TEMP Of OPHEP SO/iS /*/ THE ASSOCM T/OPS 

2/ Indicates rating used on General Land Capability Map or Hydrologic Groups Map. 




















































































































































uo 

o 

z 

Q_ 

3 

o 

o 

LU 

> 

I— 

LU 

C£ 

Cl. 

O' 

LU 

I— 

z 

Q 

z 

< 

uo 

LU 


< 

3 

0 


IS) 

U 


LT) 

CSL 

LU 

I— 

U 

< 

< 

X 

u 


O 

uo 


1-^1 
^ ^ 12 


£ 



5 


X 

O I 

o 


$ 

Li 

O 

O 

o 

o 

1 o 

>4 
: ° 

Li 1 

O 1 


8 

X 

o| 


8 

X 

! u 

o 

s^_ 

X 

u 


£ 

0 i 

8 

X 

CJ 

gioe 
f v, 


o 

a 


'aa 


« 



o 

133 


PQ 

CQ 


03 

PQ 

PQ 



CJ 

3g§B 


2 

o 

>3- 


vO 

o 

o 

O 


o 

O' 

o 

<r 

O 


oo 

O 

O 

O 


O 

O 

o 

O 

vj 


2 

0 

Vs —^ 


+ 

o 

o 

O 

-3- 

o 

O 


o 

<t 

o 

o 

00 

<r 

o 

o 

o 


o 

<r 

o 

o 

o 

<o 

o 

o 

m 

o 

-3 

O 

O 


s 

o 

o 

O 

v£> 

o 

o 


O 

X 

o 

o 

't 

s 

o 

o 

cn 

00 

<T 

O 

O 


+ 

2 

o 

o 

A 

NO 

o 

m 

11 


Lo“r 
3 •y'ro 
X X ro 

LoT 

!fl 


> X. 

& M 

> X 


00 

K 

X 

oo 

sc 

00 

K 


X 

00 

sc 

X 

00 

X 


oo 

X 

00 

X 

f 


X 

X 

00 

^ * 

5; 5! 

a a 

1 5 


>% 

to 3 
•o o 

X w 

>> 

2 

to 3 

TO O 

x: w 


Li TJ 

•o a 

x 2 

CL 

a: 

>% 

Li X> 

to a 
& 2 


M 

TO 

O 

X 

3 

o 

Li 

•o 

X 


TO 3 

T3 O 

£ 1 

L 

•s ? 

^ TO 


>. 

TO 3 
TO O 

O r-H 

x: « 

•s s 

S-3 

TO 3 

TO O 

£■3 


o >, 

Li Li 

TO TO 3 
•DTOO 

£ E^ 

| 

a 5 

h: ->i 


u u 
o o 
o 

>> CL 

1 £■ 

0- > 

>> 

o o 
o 

>N CL 

s & 

O TO 
CL. > 


J-* > 

3 W 

B o 

>-. 

*-> > 

3 2 

E O 

s s 

> 


3 

3 

3 


3 

3 


3 

3 

3 


3 


>1 

s 

«< 

5* 

a 

5*cf < 

S5fc 


3 

O H. 

co E 

E 

o to 

u c 

T) * 

•H O. 

U Li 

TO 

c 


•H 

c 

CD 

_T3 

X 

3 Li 

c 

Li 

00 

Li 

X 

LJ ^ 

i e 

C 

00 

X W 

TO "o 

3 ° 


C 

C 

CL 

Li 

C 

c 

a 

Li 

C 

c 

CL 


1 2 
w ” 

TO IV 

<u c 

0 00 

■ju 

B 01 

2 & 
^ 2 

c ^ 

E O 
-»-l Li 

to 3 

O 

TO C 

O -H 

X 

a -a 

O TO 

S 

2 & 
s 2 


c ^ 

E O 

TJ 

TO 3 

o 

TO C 

TO &0 

O i-l 

a to 

L. C 

O TO 

E 

2 

x: 2 

C X 
to o 

E O 

T3 

O 

TO C 

X 

a to 

Li C 

O TO 

2 & 

S 2 

C Ed 

B O 
i-l Li 

TO ^ 

•u TO 

m 60 

O -H 

X 

&•§ 

O TO 

B 

s & 

£ S 


O 

X 

o 

TO ^ 

X 

Li 

O 

•->» 

«-» 

5j 

«-» 

t 

v» 

s 


>> 

5 c 

CD i-l 

L i-l 

T3 H. 

X to 

>-. 

2 c 

TO H. 

O ^-< 
Z <D 


B 

a 

-H T3 

X ro 

E 

•W T3 

X TO 

B 

D 

*H -U 
•O -H 

2 TO 


3 

>> 

X ^ 

>. 

00 T5 


E 

^ TO 

E 

D 

TO 

X TO 


B 

3 

•H TO 

TO i-l 

S TO 

E 

3 

•a x 

S TO 

2 

3 

z 


>, 

oo 

c 

O TO 

>> 

00 

c 

CO CD 

Si 

& 


3 

B 


B 

o 

CD "c 

O «D 

^ 2-x: 
O O a 

►J O a 

E 

>-, O 

TO >, 

> TJ 

TO C 

Li TO 

O TO 


>> 

5 S 

C >1 
O TO 

> >> 

TO TO 

Li f-l 

O O 

> B 

Li O 

O r-l 


> 

Li >, 
00 TO 

^ US 

J-. TO 

5:^2 

E 

>, TO 
r-H O 

> >, 

Li r—1 

o p 


> 

Li >, 
00 TO 

to >>a 

S 

>> TO 
■-I O 

> >. 
to as 

L r-i 

-O O 

B 

>, TO 

> >. 

cj o 


E 

O 

>i 

TO 

CJ 

Ss 

0) 

CJ 

<* 

£ 

X 

'Si 

<»C 

*-> 

f 


u 

p 

2 

>, to 

'oo -5 

O <D 


1^ 

•o -H 

a s 

>. 

00 

c 

O "O 

B 

•U -H 

S TO 


>s 

X 

00 -O 

B 

P ^ 

X TO 

E 

P 

•H TO 

1 s 


E 

p 

TO -H 

X TO 

s 

is 


E 

3 

i-l -O 

T3 iH 

S TO 

E 

3 

i-l TO 

is 

3 

Z 


6 

•o 22 

X 

00 "O 
•H -W 

1 

>< 

a 


E 

e 

o 


B 

« >> 
d -O 

CD C 

O CD 

O W 

i' 2-o 

« CD C 
O O TO 
i-J O TO 

B 

>% o 

> •o' 

o « 


>, 

>, 

C B 
O TO 

> B 

> 

2 e 

00 TO 

£ ^ 


> B 

L. O 

o ^ 

>> 

> E 

Li O 

O l-H 


>> 

> B 

Li O 

O r-4 

>. 

> B 

Li O 

O r-l 

> B 

O r-l 


>. 

> B 
a to 

Li O 
O ^ 

B 

o 

X 

5| 

%C 



£ 


m 

m 

m 


m 

in 



CVJ 

CN 


OJ 

£ 

na 


m 

m 

gs 

sa 

'x 






M 

> 

£ 

> 


> 

> 

g 


> 

M 


M 

> 

M 

> 

> 


M 

> 

M 

> 

s 

I 



s 



















t! 1 

* fc 

Sj w» 

*• ^ 


o 

-§ 


O 

o 

o o 


cn 

o 

O in 


O 

<t 

O O 


s 

O 

in O 


O 

O 

m 

S t 

1 1 
s a 

v» 

s w ^ 

^ ^ ^ 

' ? 

c 

o 

o o. 

CD c 

Is 

< a. 

c ^ 

5 o 

c 

g 

E 

00 

3 at 
o o 

>% Li 

io a 

*-> O 

J-j in 
o 

• c 

at o 

JA LJ 

C -H <J 

3 O C 
CD w C 
J= W f- 

u cd 

c 

. 3 

X 

u 

CJ 

p 

o 

>. 

"w 

a. -to 
x g 

•H Li 

3 a. 

•H O 
jr m 

■H o 

Ph lj 

x ^ 

M C 
• o 

TO O C 

X w o 

g Si 

X 

& 

CL, 

X 

o. 

3 

cT 

o 

TO CL 
•H O 

s w 

Li O 

E TO 

O CL 

PQ O 

^ -u 

C 

0c2 r™i 

H. 

C 

3 

B 

o 

-H CL 

o o 

TO 'to 

S 

I I 

Li O 

E 

o o 

O LJ 

CO 

1 o 

AA C 

C O 

S 2 

c 

E 

o 

pq 

I 

0 

efl u 

C TO 

E 2 

S-, TO 

s “■ 

to in 

2 o 

TO 

c - 

X O <0 
Q. -H TO 
TO U O 
TO CO O 
° -H — 

X 

o. 

o 

►n 


ala 
—> 

3 



2 




X 




v£) 



s 




ON 

NO 




143 


J/ PERCENT IN (—) GIVES EXTENT OF OTHER SOUS IN THE ASSOCIATIONS. 

Indicates rating used on Hydrologic Soli Groups Map or General Land Capability Map. 

Wind erosion hazard. 





























































J/ PERCENT IN (—) GIVES EXTENT OE OTHER SOUS /N THE ASSOCIATIONS. 

2J Indicates rating used on Hydrologic Soil Groups Map or General Land Capability Map. 

3f Wind erosion hazard. 





















































oo 

o 

z 

o_ 

3 

o 

o 

LU 

> 

(— 

LU 

CXl 

Q_ 

DZ 

LU 

I— 

z 

Q 

z 

< 

uo 

LU 


< 

3 

0 


LD 

u 


uo 

LU 

u 

< 

DZ 

< 

X 

u 


O 

oo 


r^t 

o , 

.J 

cj 


CJ 

o I 

£ 

J 

1 o 

d 

-> : 

o 

hJ 

o 


hJ 

o 

p ; 

1 i-t 

o 

►J 

CJ 


g 

S3 

CJ 


X 

US 

Lr 

O 

s 


£ 

as 

CJ 


s 


ns 

u 

!=;% 

f V» 

- 


S' 

o 

a 


TJ 

a 


Q 

a 


% 

CJ 


a 

CJ 


< 



!h§I 

CO 

o 


© 

o 

CO 

o 

o 

n 

o 

o 


“ 

o 


on 

on 

o 


vO 

o 

on 

on 


o 

00 

o 

o 


o 

Mr 


vO 

o 

on 

s* ._. 

§2:1 

o 

o 

o 


+ 

o 

VO 

o 

VO 

o 

o 

-O' 

+ 

6 

o 


o 

<r 

o 

o 

<r 

o 


O 

o 

o 

o 

o 

o 


s 

o 

o 

<r 

o 

on 

o 

O 


& 

vO 

+ 

o 

vO 

o 

o 

<r 


o 

o 

<}■ 


O 

O 

o 

5 3 

\ 

l 

2 

1 


3 

O 

►J 

3 

o 

(J 

3 

3 


<UC*T 
3 -O 
o o y 
►J Z *J 

w 

I yc^r 

3 -o ^- 
0 0 4 

hJ X *. 


3 

3 

3 

O 

t-J 


41 00 
•3 -W 

Lt X 

at oo 

•3 T* 

X * 


3 
o 
• .J 

3 

3 


X X 

oo oo 

x ffi 


00 

as 

v! 

a 5 

5 $ 

*-* ? 

* 

3 

o 

>* 

Ll 

3 

O 

X 


X 

3 

o 

o >- 

X G 

3 

O 


« 3 
•u o 

O ^-1 

X as 

| 

£ 

> 


3 

O 

3 

o 


•o 

CL 

•3 

a 

to 

0 £ 


3 

O 

3 

o 


>. 

Li 3 

3 CL 

x 2 


3 

o 

35 5 

3 


3 

U O 

to 

■§ 

01 1- V* 

E o O 

o o o 

m ao 

>. 

o 

CU 


>v 

"O r-l 

X 3 

3 

B O 

co a 


3 

3 


>v 

4-1 > 

■§ S 

B o 
to * 

> 

o 

X 

0 J 


>s 

Li 

O 

O 

>* 

o 

o 

CL 


>v 

3 w 

B O 

US 4) 


3 

M 

M 

N 

V 

& 

<£ 

i! 

a 

Si'* 

^55 

5««^ 

E 

o 

1 

ts 

Q 

U 


3 

c 

80 

•H 3 

3 

V >v 

>, 

u 

"c 

>v C 
rj o 

C Q 
to -H 
w “O 

•2 >. 

•H r—t 

to > 
v- to 

e 

^ aj 

o c 

co e 

CJ "O 

"'O to 

to > 

J-< CO 

CO M 


Cl 

■v 

CL 

~o 


CL 

•o 

X 

•o 

it 

3 

tu 


■3 

•2 >, 

a .-* 

> 

to to 

U 

Lt 00 

o to 

JC o c 

O >. ! 

•o C -3 

to 

aa 


T3 

c 

0 ) 

■u us 

•H c 

CO 4) 

B 

•3 -rH 

4) T3 

>v 

® no 

Li C 

o 

T3 

C ^ 

c 

« B 

® 3 
O 3 


C 

® us 

>> C 

C B 

3 W 

£ >. 

as > 

LI L. 


c 

o 

> 

3 

eg y 
us ° 

5 

<-. 

* 

«-> 

'S' 

f 

Vi 

$ 

3 

z 


6 

a 

■v* -V 

' is 

u 

Z. 

2 c 

l-t r- 

T3 J 


>v 

2 c 

-o x 

>,<SJ 

<-< c 
00 *- 

o^ 

LtJcf 


Lt 

3 

Z 

CO 

Lt 

z 


<0 

Li 

® 

3 


c 

Cn-r-t 

•3 ® 

£ « 

>, 

2 c 

as •*-< 

4) Q 

3 JC 


>* 

00 


>* 

LJ C 

<0 tH 

Li r—1 

4) ® 

3 X 

X « 

| 

fc 

>> 

T3 E 

c n> 


» 

> E 
<■ to. 

WrS. 

« E 

n T3 8 

tw c c 

« E > 
<-< <o a 

*-> O r- 
W rH (J 



>, 

>* E 

T3 co 

e o 

>. 

TD 

c 

<55 


>N 

CJ 

>v 

>v 

o 


C 

■3 

C 

5n 

C 

o 


B 

o 

•H 

>> 

CO 


3 

C 

co 

1 

o 

-J 


>v 

c 

o 

%c 

s 

•V4 

£ 

<-> 

t 

Vi 

3 

>-. 

X 

00 3 


>* 

X 

00 3 

-r-l tH 

>v 

X 

00 T3 

1 -t *r- 

r—1 (J 
US (O 

>> 

iJ C 

. o a 
■vs X 

£ B 


- c 

^ -H 

■o CO 

f—1 

X « 

>* 4 
•-> C 
00 -H 
C r—J 
O to 
L. Jl 

co a 


En 

X 

00 -O 

>* 

X 

00 T 

CO to 


>* 

X 

00 "3 

UL to 

3 

Z 


s 

>* 

X 

00 3 


B 

3 

3 i-i 

£ S 


® 

3 

5E 

«<* 

1 

fc 

>, 

11 

to o 

US .-< 


>* 

> S 
as co 

Li O 

O hJ 

B 

o 

>> 

u b 

co C 


E 

o 

►J 

B 

o 

>, 

c 


>v 

o 

&£ 

41 O 
> -< 

B 

O 

>* 

O 


"3 

C 

•j? 

o 

£1 


>v 

j? B 
us ^ 

B 

us ° 


3 

1 

►J 


>* 

C 

o 

§ fe 

•5 

*c 

s 




S 





£ 

Jm 


CM 



OM 

CM 


CM 


CM 

§a 

N 

3 

> 







M 

t> 


M 

M 

> 

M 

M 

> 



M 

> 





M 

> 


> 

6 

I 



M 

> 

M 

M 

3 


n, 

M 

M 






M 

M 

M 



3 

M 

M 

M 

3 

M 

M 





t! ^ 

* fc 
m ^ m 

S 1 

ag 


o 

>3- 

O 

o o 


<T 

in o 

on cm 


R 

CM ^ 


on 

m o 
*n on 


O 

'J 

o o 

St 0M 


o o 


o 

on 

s fc 

1 1 
VisJ 

5 ^ v» 

"l 

** i 

o 

■o 

£ 

o o 

<0 

to c 
a- <u 

L O 

<v l. 

• a 

E « 

O 

jr o 
c *-i 

ai o 

CJ « 
l- c 
1 - o 
82 
O <0 

c 

o 

CO 

E 

O 

c 

u 

fr 

c 

o 

-2 CL 

CJ O 

O 

c 

o ai 

CJ 

o y 
i a. 

o m 

to o 
> *J 

z o 

l-t 

O 

to 

> 

z 

o 

X 

o 

c 

o 

to to 
■H 4J 

o a 
o o 

<u C 

•o a. 
£ 

to o 

£ o 

a. 

c 

•3 

a 

o 

CJ CL 

o o 

<0 

to C 

O 41 

LI O 

3 H 

CL, CL 

Cn O 

C 

as o 

Q O 

>* 

C 

to 

41 

Q 

O 

3 

CL 

C 

o 

•3 

o 

•s a. 

o 

B C 
as 4i 
oc u 

•H 41 

ls a 

3 ^ 

cr o 

as 

3 

cr 

« 

CL 

•** 

i 

O 

O 

O 

C 

•H 41 

u a 
o o 

as co 
to 

co a 

® o 
<0 Li 

1 

o 

it 

® 

O 41 

» a 
to o 

f s 

X Li 

5 °* 

1 O 

C m 

® O 

In 

c 

3 

*21 

5 

*-* 

c 

SO o 
r-» cj 





00 



O ' 

PM 



O 

CO 






ao 


on 

00 



145 


j/ pence nt /n ( —; eere/vr op othpp sous /n thp assoc/at/ons. 

2f Indicates rating used on General Land Capability or Hydrologic Soil Groups Map. 























































l46 


J/ P£FC£KT tM (—; 6/V£S £XT£KT OF OT//FX SOUS JK TK£ ASSOC/AT/OKS. 

2 / Indicates rating used on General Land Capability Map or Hydrologic Soli Groups Map. 

































































oo 

o 

z 

Q_ 

3 

o 

o 

LU 
> 
I— 

LU 

O' 

Q_ 

CXL 

LU 

J— 

z 

Q 

z 

< 

LT) 

LU 


< 

3 

o 


UQ 

U 


uo 

LU 

h— 

U 

3 

< 

X 

u 


O 

oo 



& 


S 

o 

o 

s 

: 


; 
















1 

k.% 

^ Ci 

** 

to 


"B. 

Q 


< 
















*M S — N 

o 


-J 

o 

: 


: 
















l-i 

<r 

o 


o 

-a- 

o 

o 

: 


! 
















If 

£■§ 
> X 


& 1 00 
> X 

: 


: 
















g 5! 

a 5 

1 ^ 

a 

as 


»-< T3 

•XD Cl 

O as 

2 u 

; 


: 
















1 5 
§ * 

>s 

> 

X 


*-> > 

X us 

3 “ 

O X 

: 


: 
















>4 

a 

Si'* 

5*e*« 

«$ ^ 
4S* 

c 

is 

00 

■£ J2 

3 u 


■H 

1 

C 

o 

> 

CL 

o 


X 





• 











V4 

V. 

<-> 

t 

Vi 

$ 

E 

Is 


>% 

00 

c 

o xi 

U -H 

o 

o 

-X 

•a 

c 


> 
















2 i 

1 

£ 

u 

o 

r-g 

O as 

X us 


^ E 

o o 

>N 

•r-l 

B 


X) 

O 
















«< 

2; 

x 

s 

H* 

Vi 

5 

*»e 

<-> 

■^ > 

t 

Vi 

00 

c 

o -o 


E 

D 

X3 "r-l 
^ « 

6 

3 

o 


<4-1 
















**4 

1 

*< 

ft 

<u 

o 

r-o 

<0 C 

O as 
-1 » 


5n B 

C as 

O O 

£| 

> 5 

> 


00 
















^ s ^ 




- 


K 
















% 

N *—N 

** <S> 

sa 

•x 

5 

M 

> 


> 

M 

M 

> 


> 
















E 

1 






















t! ^ 

* fc 

5 **-5 
vj tiCr 

s 1 

o 


o 

° S 


o o 
















1 5 
^ 1 
M 

^ 5 

S w ^ 

^ ^ Vi 

' ? 

* 5 

X 

o 

o 

o 

•H 

O CL 

o o 

■g c 

f* M 

u. a 

o to 

>> o 

T3 lj 

C 

3 IQ 

■o 

c 

3 

XJ 

as 

U. 

o 

as 

C us 

O 4) 
t-< a 
d-i o 
as t-i 

O l> 

U 

3 O. 
o 

o 

> ^ 
io 

3 

o 

m 

> 

X 
















aU 

o c 

O' O 

0 \ 

■- 


SI 


















147 


J/ P£fiC£HT /A/( —; Gives £XT£NT OP OTHfX SOUS /A/ THE ASSOC/AT/O/VS. 

3 Indicates rating used on General Land Capability Map or Hydrologic Soil Groups Map. 

^ Wind erosion hasard. 





















































Is given in percentages. The most prevalent feature of the soils 
within each association determined the classification or grouping used 
in tables or on maps. For example, soils in the Mendocino-Caspar- 
Empire association (0-30 percent slopes) were delineated as group B 
rather than C on the Hydrologic Soil Group Maps because 70 percent 
of the soil area belongs in that category. 

Land capability is a classification-^ of soils made primarily for 
agricultural purposes and is not designed to classify timber and range 
production potentials. Soils and climate are considered together as 
they influence use, management, and production. The classification 
has two general divisions: (l) land suited for cultivation and other 
uses; and ( 2 ) land limited in use and generally not suited for culti¬ 
vation. Both divisions have four classes, each designated by a roman 
numeral that indicates increasing hazards and limitations in land use. 
The following are descriptions of the classes: 


Land Suited for Cultivation and Other Uses 


Class I Soils in Class I have few or no limitations or hazards. 

They may be used safely for cultivated crops, pasture, 
grazing, production of forest products, recreation, or 
wildlife. 


Class II 


Class III 


Class IV 


Soils in Class II have few limitations or hazards. 

Simple conservation practices are needed when cultivated. 
They are suited to cultivated crops, pasture, grazing, 
production of forest products, recreation, or wildlife. 

Soils in Class III have more limitations and hazards 
than those in Class II and require more difficult or 
complex conservation practices when cultivated. They 
are suited to cultivated crops, pasture, grazing, 
production of forest products, recreation, or wildlife. 

Soils in Class IV have greater limitations and hazards 
than Class III, and still more difficult or complex 
measures are needed when cultivated. They are suited to 
cultivated crops, pasture, grazing, production of 
forest products, recreation, or wildlife. 


USDA. Soil Conservation Service, Land-Capability Classification , 
Agriculture Handbook Ho. 210. (Washington, U.S. Government 
Printing Office, September 1961 ). 21 pp. 


l48 











Land Limited in Use; Generally Not Suited For Cultivation 


Class V Soils in Class V have little or no erosion hazard but 

have other limitations that prevent normal tillage for 
cultivation crops. They are suited to pasture, production 
of forest products, grazing, recreation, or wildlife. 

Class VI Soils in Class VI have severe limitations or hazards 

that make them generally unsuited for cultivation. They 
are suited largely to pasture, grazing, production of 
forest products, recreation, or wildlife. 


Class VII Soils in Class VII have very severe limitations or 

hazards that make them generally unsuited for cultivation. 
They are suited to grazing, production of forest products, 
recreation, or wildlife. 

Class VIII Soils and land forms in Class VIII have limitations and 
hazards that prevent their use for cultivated crops, 
pasture, grazing, or the production of forest products. 
They may be used for recreation, wildlife, or water 
supply. 


Capability classes are further divided into subclasses that reflect 
the principal kinds of limitations: "e" for erosion, "w" for 
wetness, "s" for soil, and "c" for climate. The distribution of 
classes and subclasses is shown in the table "Distribution of Land 
Capability Classes in the Northern and Southern Basins" and on the 
General Land Capability Maps on the following pages. 

Land Resource Areas (LRA's) are geographic divisions that have parti¬ 
cular patterns of soil, climate,.water resources, topography, and 
land use. There are portions of six major land resource areas in the 
basins: LEA 4 -- the California Coastal Redwood Belt, LRA 5 -- the 
Siskiyou-Trinity Area, LRA l4 -- the Central California Coastal Valleys, 
LRA 15 -- the Central California Coast Range, LRA 21 -- the Klamath 
and Shasta Valleys and Basins, and LRA 22 -- the Sierra Nevada Range. 
These comprise, respectively, l6, 48, 3> 9, 22, and 2 percent of the 
study area. 


Erosion hazard describes the susceptibility of the soil to erosion 
by water or wind under specified conditions. Generally the risk of 
erosion depends upon the slope, texture, and structure of the soil. 
In this study, erosion hazard is an estimate of water erosion that 
can be expected if vegetal cover is removed. 


Slope is a dominant factor and determines the hazard class, as shown 
in the following tabulation: 


Low hazard 
Moderate hazard 
High hazard 
Very high hazard 


0-9 percent slope 

9-30 percent slope 

30-50 percent slope 

over 50 percent slope 


149 




Distribution of Land Capability Classes 


Land 

Capability 
Class and 
Subclass 

Area (Square Miles) 


Percent 
Of Total 
Area 


Northern 

Basins 

Southern 

Basins 

Total 


I 

- 

25 

25 

0.2 

II e 

90 

100 

190 

1.3 

II w 

4o 

145 

185 

1.3 

II s 

- 

25 

25 

0.2 

III e 

255 

65 

320 

2.2 

III w 

150 

80 

230 

1.6 

III s 

i4o 

- 

140 

0.9 

IV e 

130 

315 

445 

3.0 

IV w 

100 

- 

100 

0.7 

IV s 

370 

15 

385 

2.6 

VI e 

•1,780 

1,395 

3,175 

21.6 

VI s 

1,350 

55 

1,405 

9.6 

VII e 

2,855 

1,420 

4,275 

29.1 

VII w 

- 

10 

10 

0.1 

VII s 

2,630 

105 

2,735 

18.6 

VIII w 

- 

36 

36 

0.2 

VIII s 

745 

250 

995 

6.8 

Subtotal 

10,635 

4,o4l 

14,676 

100.0 

Water 

160 

68 

228 


Total 

10,795 

4,109 

14,904 



150 
























Distribution of the classes is shown in the following tabulation: 

Area (Square Miles) 


Erosion Hazard 
Class 

Northern 

Basins 

Southern 
Basins 

Total 

Low 

1,680 

431 

2,111 

Moderate 

560 

485 

1,045 

High 

3,070 

1,395 

4,465 

Very High 

5,325 

1,730 

7,055 

Subtotal 

10,635 

4,o4l 

14,676 

Water Area 

160 

68 

228 

Total 

10,795 

4,109 

14,904 


Effective depth is the depth of soil to claypan, bedrock, or other 
layer that stops or hinders penetration by plant roots. Available 
waterholding capacity refers to the total amount of water available 
to plants within the effective depth (maximum of 5 feet) when the 
soil is at fieId-moisture capacity. This moisture content is approx¬ 
imately that of a well-drained soil two or three days after wetting. 

Hydrologic soil groups are used to estimate runoff potential of soils, 
assuming wet soil conditions with no vegetal cover. Soils are divided 
into the following four groups, according to their influence on run¬ 
off: 

Group A - (Low runoff potential) Consists of deep, well-drained sands 
or gravels with high infiltration and transmission rates. 

Group B - (Moderately low runoff potential) Consists of moderately 
deep to deep, moderately well- to well-drained soils with 
moderately fine to coarse texture, moderately slow to rapid 
permeability, and a moderate rate of water transmission. 

Group C - (Moderately high runoff potential) Consists of moderately 
deep, moderately well-drained soils with moderately fine to 
fine texture, slowly to very slowly permeable layers at 
moderate depths (hardpan, bedrock), moderate depth water 
tables, and slow infiltration and transmission rates. 

Group D - (High runoff potential) Consists of shallow, poorly drained 
soils with a claypan or clay layer that is nearly impervious, 
high water table, and very slow infiltration and transmission 
rates. 

Distribution of Hydrologic Soil Groups is as follows: 


151 










































I- m mm i m a i 



a 


•*£'£‘£21* 


NOVEMBER 1971 
° 


GENERAL LAND CAPABILITY MAP 
NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 






















' 



















Area (Square Miles) 


Hydrologic 
Soil Group 

Northern 

Basins 

Southern 

Basins 

Total 

A 

4io 

6l 

471 

B 

6,520 

2,880 

9,400 

C 

1,965 

470 

2,435 

D 

1,740 

630 

2,370 

Subtotal 

10,635 

4,o4i 

14,676 

Water Surface 

160 

68 

228 

Total 

10,795 

4,109 

14,904 


The Hydrologic Soil Groups Maps on the following pages show the 
location and distribution of these soil groups. Soils and subsoils 
were grouped into the Unified Soil Classification System, using the 
procedures shown in the PCA Soil Primer by the Portland Cement 
Association (Chicago, 1962 , 52 pp.). 

SOIL EROSION CLASSES 

In the Southern Basins, severity of existing sheet and gully erosion 
was estimated by examining aerial photographs for selected sample areas 
and by field checking. Areas that had visible sheet and gully erosion 
were delineated on the photographs and were categorized into moderate 
or severe erosion classes. The remainder of the areas was assumed to 
be slightly eroded. Since sheet and gully erosion from watershed 
slopes was not a major problem in the Northern Basins, this type of 
study was not made in that area. 

The area of each erosion class was estimated by statistical methods, 
using eroded areas of samples. About 320 square miles are in the 
moderate erosion class, usually with 5 to 10 linear miles of gullies 
per square mile; and about 80 square miles are in the severe erosion 
class, which commonly has 10 to 20 linear miles of gullies per square 
mile. Approximately 50 percent of the Yorkville soils, 15 percent of 
the Maymen-Los Gatos Soils, and 30 percent of the Laughlin soils are 
moderately or severely eroded. Although these soils differ in erosion 
hazard, variations in the percentages are mainly attributable to 
differences in use and management, as reflected by vegetal cover 
density. 


152 
































lodoisoqa 


IZ61 H38W3AON 





ONIOOON3W NU3HinOS 

N'vissntj NusHiaoN 
Nvissna Na3Hinos 


1V1SVOO ONIOOON3H J3Q 
B3Aia Nvissna 0 3 
3MV| BV330 V 
SNISV9 


'saiiNnoo vimonos onv ‘oniooonbw ‘3»vi 'icnoawnH 

SNISVS d3Aia Nd3HinOS 

sdnodo nos oioonodQAH 

















□ □□□ 



SaMtp&eSESSSB*-. 


HYDROLOGIC SOIL GROUPS 

NORTHERN RIVER BASINS 

CALIFORNIA AND OREGON 


NOVEMBER 1971 

i- ? 

SCALE I <1,250,000 


LOCATION