USGS Earthquake Hazards Program vs USGS Water Services

The USGS Earthquake Hazards Program's FDSNWS Event Web Service is a keyless REST API for querying the agency's global earthquake catalog by region, time window, magnitude, or depth, returning real-time and historical seismic event data. Requests default to QuakeML XML but can also return GeoJSON, CSV, or KML via a format parameter, and the whole service is free and unauthenticated, run directly by the federal government.

USGS Water Services is a keyless REST API serving real-time and historical streamflow, groundwater, and water-quality readings from thousands of USGS monitoring sites across the US, in WaterML XML, JSON, or the legacy tab-delimited RDB format. The agency has announced it will decommission this API family in early 2027 in favor of its new Water Data APIs (api.waterdata.usgs.gov), with no degradation planned before August 2026 — new integrations should target the successor service.