FLOOD10854 (2) - Laserfiche WebLink

Home Browse Search

In addition to an active floodplain management program, the major flood protection measures, by basin, are listed below: South Platte River The Chatfield Dam and Lake along the South Platte River were authorized for construction by the 1950 Flood Control Act. The dam is located on the South Platte River just downstream from the mouth of Plum Creek, south of Denver. The.'. reservoir has a storage capacity of 385,000 acre-feet, including 215,000 acre-feet for flood storage and 20,000 acre-feet for sediment control. The project provides a high degree of protection for metropolitan Denver and for extensive agricultural lands downstream (Reference 4). Clear Creek There are 11 major reservoirs in the lower Clear Creek basin, 3 of which, Ralston Reservoir, Maple Grove Reservoir, and Leyden Lake, are on-stream and provide some residual flood control effects downstream from each site. None of these reservoirs has a specific flood control function. Ralston Reservoir, located west of Denver and northwest of the City of Golden, was built in 1938 by the City and County of Denver. It receives water from Ralston and South Boulder Creeks and is used for municipal water supply. The outlet works deliver water to the Moffat Treatment Plant and have the capability of forcing the natural inflow back into Ralston Creek. Although Ralston Reservoir is not operated for flood control purposes, there is approximately 2,400 acre-feet of storage available between the primary spillway crest at elevation 6,049 feet North American Vertical Datum of 1988 (NAVD) and the top of the dam at elevation 6,063 feet NAVD. This storage provides incidental flood control. Maple Grove Reservoir, which is located on Lena Gulch in the City of Lakewood, is owned by Consolidated Mutual Water Company and is used for municipal water-supply storage. The reservoir provides some attenuation of flood peaks. Approximately 452 acre-feet of storage are available between the crest of the inlet at elevation 5,523 feet NA VD and the top of the fabridam at elevation 5,534 feet NA YD. Leyden Lake is an irrigation water-storage reservoir on Leyden Creek northwest of Denver. There are approximately 550 acre-feet of uncontrolled storage between the spillway crest at 5,615 feet NA VD and the crest of the dam at elevation 5,623 feet NA VD (References 22 and 23). Bear Creek The completion of the Bear Creek Dam just downstream of the Town of Morrison has greatly affected the peak discharges of Bear Creek. Designed by the USACE, the dam provides a flood control reservoir that intercepts flows from areas in the upper and middle parts of the basin. At the Bear Creek Reservoir, peak flows from the I-percent-a1ll1ual-chance event have been reduced from 30,000 cfs to approximately 10