5.1 SOUTH PLATTE RIVER BASIN
The South Platte River basin drains an 18,924 square mile area in the northeastern quarter of Colorado (Figure 5.1-1). The basin along with the Laramie River and Republican/Arikaree Rivers defines Water Division 1, with the divisional office in Greeley. As of early 2001, there were nearly 12,000 alluvial wells of record in the South Platte River basin.
Figure 5.1-1 Location of the South Platte River basin showing extent of mapped alluvium and distribution of alluvial wells.
(Click image to zoom .8MB)
Originating high in the Rocky Mountains, the mainstem of the South Platte River and its many tributaries descend through high, glaciated mountain valleys before incising deep canyons through the foothills. Well known tributaries include the Big Thompson, Cache la Poudre, and St. Vrain Rivers, and Boulder, Clear, and Cherry Creeks. From Colorado, the South Platte River continues east to join the North Platte River at North Platte, Nebraska and then on to join the Missouri River south of Omaha. Nine trans-mountain diversions import over 400,000 acre-feet of water annually into the South Platte River watershed from west-slope basins, exceeding the imports into all other basins in the state. Over 1.1 million acre-feet of water are stored in 22 reservoirs within the basin.
In the foothills west of Denver, the South Platte River provides numerous
recreational opportunities. Photo courtesy of Denver Post.
According to the 2000 Census, approximately 3 million people, or 70 percent of the state’s population, live within the basin along the Front Range urban corridor. Aside from the urban and growing suburban land use, the region is an important agricultural area with over 1 million acres of irrigated cropland.