Interstate compacts, which are agreements between two or more states, govern specific interactions among those states and require consent by the U.S. Congress.
The State of Colorado is party to the following interstate compacts and equitable apportionment decrees:
Colorado River Basin
These compacts allow Colorado to use up to 3.85 million acre feet (MAF), provided the Upper Basin does not cause the flow at Lee Ferry, Ariz., to fall below 75 MAF, based on a 10-year running average (7.5 MAF/year). To learn more, see the Coordinated Long Range Operating Criteria. Learn about Compact Administration in this presentation.
This compact apportions the waters of the La Plata River between Colorado and New Mexico, by allowing the unrestricted right to use waters by both states between December 1 and February 15, and allocating specific flows and deliveries between February 16 and November 30.
This compact provides agreements that allow for the operation of the Animas-La Plata Project.
Rio Grande River Basin
The 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.
The compact establishes uses, allocations and administration of the waters of Costilla Creek in Colorado and New Mexico.
In addition, the Director of the Colorado Water Conservation Board (CWCB) is a voting member of the Arkansas River Compact Administration, and CWCB staff provide engineering and legal advice to the Administration. Staff members also are designated representatives to the Engineering and Legal Committees of the Upper Colorado River Commission.