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basis. This will increase the probability of sporadic overflows from the canals, which can cause severe damage, particularly if an embankment fails. For this reason, separation of drainage flows and irrigation flows should be considered for at least the lower frequency events (Reference 1). There is a levee on the right bank of the Cache La Poudre River upstream of Timberline Road that blocks flows that previously split down the Cache La Poudre RPATH. There are two irrigation dams on the North Fork Cache La Poudre River. The effect of the two dams is considered negligible in the study area. There are no flood control structures that reduce discharges on Buckhorn Creek, Redstone Creek, Fish Creek, Black Canyon Creek, or the Fall River. The Horsetooth and Dixon Reservoirs are two major reservoirs within the Spring Creek basin. The Dixon Reservoir is located on the western edge of the basin immediately below the hogback that impounds the Horsetooth Reservoir. The Dixon Reservoir intercepts and stores runoff from approximately 250 acres of drainage area, making this area essentially non-contributing to the Spring Creek channel. The Horsetooth Reservoir is owned by the USBR and operated by the Northern Colorado Water Conservancy District. It was completed in the early 1950s as a water-supply reservoir, but has also helped reduce flooding problems in Spring Creek by reducing the tributary drainage area. The total drainage area for Spring Creek is approximately 30 square miles. Downstream of the Horsetooth Reservoir, the drainage area is approximately 12 square miles. The outlet works for the Horsetooth Reservoir are located on the north end of the reservoir, discharging to a water-supply canal. The outlet and canal are not within the boundaries of the Spring Creek basin. Off-stream detention ponds are located throughout the Spring Creek basin. In most cases, these ponds were designed to control local runoff and, in general, appear to have little effect on flows along Spring Creek. However, the Rossborough, Woodwest, Fairbrooke, and Colorado State University Animal Medical Center ponds have relatively larger storage areas and may have some effect on flows in Spring Creek. These ponds are controlled and operated by the City of Fort Collins for flood-control purposes and were included in the hydrologic analyses. Additionally, several man-made embankments for road and railroad crossings within the Spring Creek basin result in some flood attenuation. These crossings include the Taft Hill Roadway, Overland Trail Roadway, and Burlington Northern Railroad (BNRR) west of College Avenue, and the Colorado and Southern Railroad (C&SRR) west of Timberline Road. These areas were considered for detention in the hydrologic analysis. The Town of Estes Park is replacing old bridges with bridges designed to avoid bridge backwater by perching the new bridges above the channel. Flood flows spill from the channel before water rises to the low chord of the bridge. The bridge does not create a backwater hence, it does not increase the flood hazard. Future replacement of inadequate bridges with these perched bridges will reduce flood potential in some areas. Larimer County is providing some protection from floods through flood warning and forecasting by the National Oceanic and Atmospheric Administration (NOAA), National Weather Service. Also, the City of Fort Collins operates a flood warning system consisting of over fifty gage sites that measure rain and/or water level. 18