National Water Information System (NWIS)

RESOURCE DESCRIPTION

The National Water Information System (NWIS) is a national repository of water resources data maintained by the US Geological Survey (USGS). It includes point-based water data from over 1.5 million sites in the United States, Puerto Rico and the U.S. Virgin Islands. These data include water quality, groundwater, surface water, well, and stream gauge data. Real-time data are recorded at 15- to 60-minute intervals, stored onsite, and then transmitted to USGS offices every 1-4 hours via satellite, telephone, and radio telemetry. Recording and transmission times can be more frequent during critical events. The database includes information on the occurrence, quantity, quality, distribution, and movement of surface and underground waters. Specifically, peak streamflow for surface waters as well as daily, monthly, and annual statistics for groundwater and water quality are available online. Additionally, users may query the NWIS using WaterNow, a data-on-demand system where users input the river gauge number are sent the latest information for that gauge via text/e-mail. During a flood event, the US Army Corps of Engineers (USACE) uses NWIS to view stream gauge heights in the affected area to determine where flooding may be most severe. This information may be used to support Federal Emergency Management Agency (FEMA) Mission Scoping Assessments, helping to define the scope of the recovery assistance mission.

BROAD DATA CATEGORIES

• Weather

SPECIFIC DATA ELEMENTS

• Flood
• Inundation
• Drought

GEOGRAPHIC COVERAGE

US States; Puerto Rico; US Virgin Islands