The following databases index articles from scholarly, scientific journals.

USGS Publication Warehouse
https://pubs.er.usgs.gov/
Government reports, statistics, and data for all aspects of geology.

NRCS - Natural Resources Conservation Service
https://www.wcc.nrcs.usda.gov/wsf/westwide.html
From the Department of Agriculture, this site provides statistics, data, and maps for water supplies, streamflows, snowpacks and other climate information.

Water Supply Outlook for the Western United States
https://www.cbrfc.noaa.gov/wsup/westwide/westwide.cgi
Published jointly by NOAA and the Colorado Basin River Forecast Center, this site provides data from the past 20 years, as well as the forecast for water supplies, streamflows, snowpacks and reservoir storage.

U.S. Drought Portal
https://www.drought.gov/drought/
Monitors and forecasts drought and it's impacts in the United States.

Statistical Abstract of the United States

The official federal summary of statistics and provides over 1,400 tables of benchmark measures on the demographic, housing, social, political, and economic condition of the United States.