Rio Grande River Basin
The Colorado portion of the Rio Grande Basin, located in south central Colorado, encompasses approximately 7,543 square miles (7.2 percent of the state’s area). The San Luis Valley is a primary feature of the basin, extending from the foothills of the San Juan Mountains east toward the Sangre de Cristo range. Major tributaries include Alamosa River and Conejos River.
1 Source: CDSS, total values derived from GIS Data for Rio Grande Basin
2 Source: Statewide Water Supply Initiative Fact Sheet for Rio Grande Basin, CWCB, 2006
- Rio Grande Compact of 1938: The Rio Grande Compact establishes Colorado’s obligation to ensure deliveries of water at the New Mexico state line and New Mexico’s obligation to assure deliveries of water at the Elephant Butte Reservoir, with some allowance for credit and debit accounts.
- Amended Costilla Creek Compact of 1963: The Amended Costilla Creek Compact establishes uses, allocations, and administration of the waters of Costilla Creek in Colorado and New Mexico.