Colorado River Water Rights: Property Rights in Transition

The Colorado River, flowing through 1,300 miles of Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, and California,1 is a primary source of water for the arid Western United States.2 As the lifeblood for so many, the Colorado River has long been at the heart of controversies over water rights.

Rapid population growth3 and a recent drought4 have both increased demand for and decreased supply of the water resources of the Colorado River, resulting in heightened conflict over water rights on the river. The interest groups competing for these water rights include irrigation water districts (groups that sell water to farmers for agricultural uses), municipal water districts (groups that sell water to city dwellers for household uses and to companies for industrial uses), and the federal government (which uses water for environmental purposes, such as protecting endangered species,5 and other public purposes6).

Historically, water rights in the Colorado River were established by first possession and included limited transfer rights.7 As a result of these historical rules, the vast majority of water rights vested in traditional farming communities.8 With Western urban population growth, the demand for urban uses of water has rapidly grown.9