Based on the visual inspection, available records, past operational performance, and in accordance with the guidelines criteria established for these studies, Lake Montebello is judged to be in good condition. The water level in Lake Montebello is normally maintained between elevation 160 and elevation 162 by way of the intermittent operation of a 10-inch gravity connection from the Montebello washwater lake. Other sources of inflow to the lake include: (1) Plant sludges dredged from the washwater lake, (2) Plant sludges from the filtered water reservoirs, (3) Plant sludges from the lime tower (future), (4) Possible surface water runoff from the loop raod on the perimeter of the lake, and (5) Rainfall on the lake surface. Surface water runoff from the drainage areas upstream is intercepted by a major stormdrain system and is directed around the lake by way of the 108-inch Montebello Drain Tunnel which discharges into Herring Run. Therefore, except for Items 4 and 5 previously listed, all inflow into the lake is controlled and flood routing is not required. Although an overflow in the Montebello Gate House limits the theoretical maximum lake water level to elevation 164.3, the lake water levels are actually controlled by limiting inflow from the washwater lake.