Retrieve historical groundwater-level field measurements for a USGS monitoring location using the modernized api.waterdata.usgs.gov OGC API (the legacy waterservices.usgs.gov /gwlevels endpoint is decommissioned)
domain: api.waterdata.usgs.gov · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Confirm you are not using the retired path: legacy waterservices.usgs.gov /gwlevels was decommissioned starting Nov 1, 2025 and no longer returns current data
Query GET https://api.waterdata.usgs.gov/ogcapi/v0/collections/monitoring-locations/items filtered by state_code, county_code, or a bounding box to find the target well's monitoring_location_id
Query GET https://api.waterdata.usgs.gov/ogcapi/v0/collections/field-measurements/items filtered by that monitoring_location_id to get discrete manually-collected groundwater-level readings (this replaces /gwlevels)
For automated sensor-logged groundwater levels instead of discrete field visits, use the /continuous or /daily collections rather than /field-measurements
Register for a free API key at https://api.waterdata.usgs.gov/signup if making more than a few requests per hour; anonymous access is rate-limited
Known gotchas
Field names changed completely from the legacy WaterML/JSON schema (e.g. siteCode -> monitoring_location_number, variableName -> parameter in /time-series-metadata) — old parsing code will not work against the OGC API
/field-measurements now mixes groundwater-level readings with stream discharge and gage-height readings from the old /measurements endpoint — filter by parameter_code to isolate groundwater data
There is no single query for a whole HUC/basin/county pull — first query /monitoring-locations for IDs in the area, then query the data collection with those IDs
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