Colorado's River Compacts
Colorado is part of nine interstate river compacts, documents which govern the use of rivers crossing state lines. Key to equitable allocation of the West's most precious resource—water—the compact clause of the U.S. Constitution was first applied to rivers in the 1920s, an idea conceived and promoted by Greeley water lawyer Delph Carpenter.
The first and best example is the Colorado River Compact. A brief document—less than 2,000 words—the Colorado River Compact emerged after nearly a year of negotiations and gained ratification only after seven years of political debate. The Compact still proves contentious today as drought, growth and the environment affect western states and their water needs.
Of Colorado’s nine compacts, Delph Carpenter had involvement to a greater or lesser extent with the first seven completed. His epithet “Father of Interstate River Compacts” is most appropriate.
Colorado’s Compacts
- 1922 - Colorado River Compact, with Arizona, California, Nevada, New Mexico, Utah and Wyoming
- 1922 - La Plata River Compact, with New Mexico
- 1923 - South Platte River Compact, with Nebraska
- 1938 - Rio Grande Compact, with New Mexico and Texas
- 1942 - Republican River Compact, with Kansas and Nebraska
- 1948 - Arkansas River Compact, with Kansas
- 1948 - Upper Colorado River Compact, with New Mexico, Utah and Wyoming
- 1963 - Costilla Creek Compact, with New Mexico
- 1968 - Animas-La Plata Project Compact, with New Mexico
Facts about the Colorado River Compact
- Divides Colorado River Basin into upper and lower basins at Lee Ferry, Arizona
- Upper Basin states: Colorado, New Mexico, Utah and Wyoming
- Lower Basin states: Arizona, California and Nevada
- Apportions the right to exclusive beneficial consumptive use of 7.5 million acre-ft in perpetuity to the Upper Basin and the Lower Basin
- Allows an additional 1 million acre-ft per year of increased beneficial consumptive use to the Lower Basin
- Provides that the Upper Basin states will not cause the flow at Lee Ferry to be depleted below an aggregate of 75 million acre-ft for any period of 10 consecutive years
Defining Dates of the Colorado River Compact
- 1920 - Compact clause of U.S. Constitution first proposed for interstate river appropriation
- 1921 - Congress authorizes compact negotiations; Commissioners appointed from seven states
- 1922 - Negotiations throughout the year; Commission approves final draft November 24th
- 1928 - Boulder Canyon Project Act enacted by Congress
- 1929 - President Hoover signs Act, making Compact official
- 1931 - Construction of Hoover Dam begins
- 1936 - Hoover Dam completed
- 1944 - Arizona ratifies Colorado River Compact