Wyoming State Water Plan, Wyoming Water Development Office
Rafting on Snake River Lake Marie, Snowy Mountains Wyoming Wind River Range picture

Introduction

"The Law of the River" as applied to the Colorado River, has evolved out of a combination of both Federal and State statutes, inter-State compacts, court decisions and decrees, contracts with the United States, an international treaty, operating criteria and administrative decisions. All of the foregoing have resulted in a division or apportionment of the waters of the Colorado River among users and of the rights to the "consumptive use" of the Colorado River waters. They reflect the fact that for over a hundred years, the financial strength and national authority of the U.S. Congress has been absolutely necessary to avoid interstate disputes and to secure economic stability for the Colorado River basin. Floods in the lower Colorado River in the first years of this century caused extensive damage and created the Salton Sea, bringing urgency to the desires of California irrigators for an all-American canal and a dam that would regulate the river. The California interests sought financial support for these projects from Congress. The upper basin States were wary that the lower basin would develop at the expense of the upper basin, and successfully blocked these efforts in Congress. The upper and lower basins resolved their differences in 1922 when they signed the Colorado River Basin Compact. The Compact divides the river's water between the basins and also sets a requirement that the upper basin not deplete the flow of the river below 75 million acre feet over any 10-year period.

The Colorado River has been described as the most closely regulated and controlled stream in the United States. Between 1962 and 1979, water has been released from Hoover Dam in quantities sufficient to meet only the requirements for delivery to Mexico under the Mexican Water Treaty and the downstream requirements under water delivery contracts with the Secretary of the Interior. The released water generates power but water is not released for the sole purpose of generating power. Consequently, there are only minimal flows in the Colorado River below Morelos Dam, the last dam on the river which was built by Mexico to divert water for use in Mexico