San Juan Watershed Program

Lake Powell Coring Project

EPA Resources:

Water resources in the San Juan River watershed, an area that encompasses the San Juan and Animas Rivers and that flow into Lake Powell, are important for recreational, agricultural, biological, cultural, and residential uses in the Four Corners area. Potential contamination sources within the watershed include historic mining activities that disturbed the land and mobilized naturally occurring metals.

On August 5, 2015, a large release of metal-laden mine water – now known as the Gold King Mine spill – was discharged into Cement Creek, a tributary to the Animas River in Colorado. EPA modeled and predicted that the metals released during this event traveled downstream to the San Juan River, and currently reside in sediments of Lake Powell in southeastern Utah.

In 2016, under the Water Infrastructure Improvements for the Nation (WIIN) Act, the U.S. Congress authorized appropriations of $4 million per year in 2017–2021 for a long-term water quality monitoring program for the San Juan River watershed. The Environmental Protection Agency (EPA) and the states and tribes adjoining the watershed—Arizona, Colorado, New Mexico, Utah, the Navajo Nation, the Ute Mountain Ute Tribe, and the Southern Ute Indian Tribe—are working together to develop and implement the long-term water quality monitoring program. These groups will:

  • Develop collaborative, annual water-quality and sediment monitoring plans and determine the need for additional monitoring.
  • Communicate information about the condition of the watershed to the public.
  • Conduct targeted monitoring and research activities to inform state and tribal decisions for watershed management.

DEQ is currently working with a variety of partners on several projects in the San Juan River watershed that will ultimately provide the necessary information to guide research moving forward and identify remediation strategies to address mine-associated contaminants.

For additional information, please contact Lucy Parham (