WSP01414 - Laserfiche WebLink

Home Browse Search

CHAPTE R 3 WATER RESOURCES OF THE BASIN Hydrology The total surface water supplies in the South Platte River basin in Colorado have been estimated to average 1.8 million acre-feet annually, of which over 300,000 acre-feet are attributed to transbasin imports. The basin's water uses, primarily irrigated agriculture, are estimated to consumptively use approximately 1.5 million acre-feet annually (U.S. Department of the Interior, 1974; Toups Corporation, 1975). From a basinwide water balance, basin outflows are estimated to have been more than 300,000 acre-feet in an average year; however, seasonal and year-to- year variability of streamflows in the basin is considerable. The hydrology of the South Platte River basin is discussed in terms of the major tributaries of the basin. The tributaries of the South platte River can he classified into two general types. The first is the "mountain" tributary, which as the name suggests, originates in the Rocky Mountains along the eastern slope of the Continental Divide (Figure 2). Runoff in these streams results primarily from the melting snowpack during the spring and early summer months. Mountain tributaries of the South Platte River include the North, Middle, and South Forks of the South Platte River, Bear Creek, Clear Creek, St. Vrain Creek, the Big Thompson River and the Cache 1a Poudre River (Figure 1). The second type is the "plains" tributary. Runoff on these streams results primarily from intense thunderstorms during the spring and summer months. Although spring and summer thunderstorms causing rainfall on plains drainages can cause severe flooding, these streams do not in general provide major flows to the total basinwide water supply. The plains tributaries include Plum, Cherry, Box Elder, Kiowa, Bijou, Badger, Beaver and Wildcat Creeks (Figure 1). -26- I I I I I I I I I I I I I I I I I I I