Map: monthly average precipitation
This map shows total rain and snowfall in the contiguous United States, every month from 1981 to the present. The map's color scale runs from white (no precipitation), to blue (significant...
Data viz: surveying Colorado River Basin maps
This collection of Colorado River Basin maps includes public domain images and other cartographic resources for depicting the watershed.
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...
Data viz: explore our interactive dashboards for drought, precipitation and snowpack
These maps and visualizations let you interact with vital data on our water supply.
Map: weekly drought reports
This map depicts data from the National Drought Mitigation Center. Drought intensity categories are based on numerous indicators and local reports from more than 350 expert observers...
Map: daily nationwide snowpack
This map shows daily snowpack estimates for the contiguous United States since October 2003. Using the dropdown menu above the chart – or clicking a state on...