Wednesday April 2, 2025
USGS —
The Colorado River is not a naturally flowing river, not anymore. With Glen Canyon Dam upstream and Hoover Dam downstream, the Colorado River in Grand Canyon is one of the most highly regulated water systems in the world. Its flow generates hydroelectricity, irrigates crops and provides water to nearly 40 million people across seven U.S. states, 30 Tribal Nations and two Mexican states.
Managing the Colorado River Basin is complicated. Federal, state and Tribal agencies balance the needs of many user groups, from anglers to farmers to city municipalities. They also care for the river as an ecosystem, home to rare fish and the foundation of Grand Canyon, one of the Nation’s natural treasures. In an era of heat waves and drought, when there is less water than ever to go around, managers increasingly need high-quality science to respond to emerging challenges.
The USGS provides critical science to resource managers in the Colorado River and Grand Canyon. Our stream gages monitor water quality and flows, our researchers track fish populations and our modelers forecast how resources may respond to future conditions. We help managers anticipate new threats and consider potential outcomes of management decisions.