Map: U.S. dams and reservoirs

The Global Reservoir and Dam Database (GRaND) is a survey listing about 7,000 larger dams and reservoirs worldwide, including 1,920 in the United States. Data includes such parameters as the name of the dam and reservoir, the river impounded, the primary purpose of the project, its year of construction or commissioning, and the area and volume of the reservoir. 

The timeline at the bottom of the screen shows how reservoir storage capacity grew over time in the selected geographic area. 

Using the dropdown menu above the chart will zoom in to the selected state or region. Clicking on the timeline or dragging the slider will update the display to show dams in existence by the selected year.



See this post to learn more about our other interactive data visualizations.

The Water Desk’s mission is to increase the volume, depth and power of journalism connected to Western water issues. We're an initiative of the Center for Environmental Journalism at the University of Colorado Boulder. The Water Desk launched in April 2019 with support from the Walton Family Foundation. We maintain a strict editorial firewall between our funders and our journalism. The Water Desk is seeking additional funding to build and sustain the initiative.