# USGS Water Services **Canonical:** https://apis.io/providers/usgs-water/ **Website:** https://waterservices.usgs.gov/ **APIs profiled:** 43 The U.S. Geological Survey (USGS) National Water Information System (NWIS) exposes a suite of REST APIs providing access to real-time and historical water data from over 1.5 million monitoring locations across the United States and territories. The legacy WaterServices APIs (being decommissioned in early 2027) and the next-generation api.waterdata.usgs.gov OGC-compliant APIs together cover streamflow, groundwater levels, water quality, site metadata, and statistical summaries. All services are free, publicly funded, and require no authentication for standard use; API keys are available at no cost for higher rate-limit access. ## Kin Score — 48.6 / 100 (developing) Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+1.8 from 46.8). | Facet | Score | |---|---| | Discoverability | 68.5 | | Contract Quality | 60.8 | | Governance | 9.8 | | Contract Governance | 9.8 | | Operational Transparency | 36.8 | | Developer Ergonomics | 21.4 | | Commercial Clarity | 63.2 | | Access Clarity | 63.2 | Regulatory layer — **Government & Public Sector**: 46.3 (matched via tags). ## Agent readiness — 29.1 (agent-aware) | Dimension | Value | |---|---| | Spec Presence | yes | | Agentic Access | derived | | Reversibility Documented | no | | MCP Server | no | | Auth Clarity | yes | | Idempotency | no | | Error Semantics | no | | OpenAPI Examples | no | | Rate Limit Signal | documented | | Event Surface Described | no | | Agent Skills | no | | Well Known Catalog | no | | Consent Identity | no | | Agent Card | no | | Dry Run Mode | no | ## Access Free · Open access — onboarding: open, pricing: free, trial: no (confidence: high). ## APIs (43) - **USGS Instantaneous Values Service** — Provides near real-time water data — streamflow, gage height, temperature, specific conductance, and hundreds of other parameters — from thousands of USGS monitoring sites. Valu... - **USGS Daily Values Service** — Returns historical summarized daily hydrologic data (mean, median, maximum, minimum) for streams, lakes, estuaries, and wells. Many sites have more than 10 years of record. Supp... - **USGS Site Service** — Searches and retrieves metadata for millions of USGS hydrologic data collection sites including streams, springs, wells, lakes, reservoirs, estuaries, and glaciers. Filtering op... - **USGS Statistics Service** — Retrieves daily, monthly, or annual statistics (mean, minimum, maximum, median, and percentiles P05–P95) computed from approved historical time-series data. Supports up to 10 si... - **USGS Groundwater Levels Service** — Provides historical manually-recorded groundwater level measurements from USGS wells and monitoring sites. Returns depth-to-water and water-level-above-datum values in JSON or R... - **Water Quality Portal (WQP) API** — A cooperative service sponsored by USGS and EPA providing access to water quality data from over 400 agencies including USGS NWIS and EPA WQX. Endpoints cover monitoring sites, ... - **USGS Water Data Statistics API** — Next-generation statistics API at api.waterdata.usgs.gov providing computed statistical summaries for USGS water time series. Part of the platform replacing the legacy WaterServ... - **USGS Water Services agency-codes API** — Code identifying the agency or organization used for site information, data sources, and permitting agencies. Agency codes are fixed values assigned by the National Water Inform... - **USGS Water Services altitude-datums API** — The recommended vertical datum is NAVD88 (North American Vertical Datum of 1988) where applicable as stated in Office of Information Technical Memo 2002.01. NGVD29 (National Geo... - **USGS Water Services aquifer-codes API** — Local aquifers in USGS data are identified by an aquifer name and geohydrologic unit code (a three-digit number related to the age of the formation, followed by a 4 or 5 charact... - **USGS Water Services aquifer-types API** — Groundwater occurs in aquifers under two different conditions. Where water only partly fills an aquifer, the upper surface is free to rise and decline. These aquifers are referr... - **USGS Water Services channel-measurements API** — Channel measurements taken as part of streamflow field measurements. - **USGS Water Services citations API** — Citations associated with water measurement methods. - **USGS Water Services combined-metadata API** — This endpoint combines metadata from timeseries and field measurements collections by site. - **USGS Water Services continuous API** — Continuous data are collected via automated sensors installed at a monitoring location. They are collected at a high frequency and often at a fixed 15-minute interval. Depending... - **USGS Water Services coordinate-accuracy-codes API** — Appropriate code on the schedule to indicate the accuracy of the latitude-longitude values. - **USGS Water Services coordinate-datum-codes API** — Horizontal datum code for the latitude/longitude coordinates. There are currently more than 300 horizontal datums available for entry. - **USGS Water Services coordinate-method-codes API** — Methods used to determine latitude-longitude values. - **USGS Water Services counties API** — The name of the county or county equivalent (parish, borough, planning reagion, etc.) in which the site is located. List includes Census Bureau FIPS county codes, names and asso... - **USGS Water Services countries API** — FIPS country codes and names. - **USGS Water Services daily API** — Daily data provide one data value to represent water conditions for the day. Throughout much of the history of the USGS, the primary water data available was daily data collecte... - **USGS Water Services field-measurements API** — Field measurements are physically measured values collected during a visit to the monitoring location. Field measurements consist of measurements of gage height and discharge, a... - **USGS Water Services field-measurements-metadata API** — This endpoint provides metadata about field measurement collections, including when the earliest and most recent observations for a parameter occurred at a monitoring location a... - **USGS Water Services hydrologic-unit-codes API** — Hydrologic units are geographic areas representing part or all of a surface drainage basin or distinct hydrologic feature identified by a unique number (HUC), and a name. The Un... - **USGS Water Services latest-continuous API** — This endpoint provides the most recent observation for each time series of continuous data. Continuous data are collected via automated sensors installed at a monitoring locatio... - **USGS Water Services latest-daily API** — Daily data provide one data value to represent water conditions for the day. Throughout much of the history of the USGS, the primary water data available was daily data collecte... - **USGS Water Services latest-field-measurements API** — Field measurements are physically measured values collected during a visit to the monitoring location. Field measurements consist of measurements of gage height and discharge, a... - **USGS Water Services medium-codes API** — Medium refers to the specific environmental medium from which the sample was collected. Medium type differs from site type because one site type, such as surface water, could ha... - **USGS Water Services method-categories API** — Categorical standards for methods describing the associated data's appropriateness for an intended use. - **USGS Water Services method-citations API** — Citation identifiers for water measurement methods. - **USGS Water Services methods API** — Water measurement or water-quality analytical methods. Codes and descriptions defining a method for calculating or measuring the value of a water quality or quantity parameter. ... - **USGS Water Services monitoring-locations API** — Location information is basic information about the monitoring location including the name, identifier, agency responsible for data collection, and the date the location was est... - **USGS Water Services national-aquifer-codes API** — National aquifers are the principal aquifers or aquifer systems in the United States, defined as regionally extensive aquifers or aquifer systems that have the potential to be u... - **USGS Water Services parameter-codes API** — Parameter codes are 5-digit codes and associated descriptions used to identify the constituent measured and the units of measure. Some parameter code definitions include informa... - **USGS Water Services peaks API** — Annual peak flow values are the maximum instantaneous streamflow values recorded at a particular site for the entire water year from October 1 to September 30. Note that the ann... - **USGS Water Services reliability-codes API** — Code indicating the reliability of the data available for the site. - **USGS Water Services server API** — These APIs provide OGC-compliant interfaces to USGS water data, letting you download continuous sensor measurements, discrete field measurements, metadata about monitoring locat... - **USGS Water Services site-types API** — The hydrologic cycle setting or a man-made feature thought to affect the hydrologic conditions measured at a site. Primary and secondary site types associated with data collecti... - **USGS Water Services states API** — State name or territory. Includes U.S. states and foreign entities classified under FIPS as 'Principal Administrative Divisions'. - **USGS Water Services statistic-codes API** — Statistic codes. - …and 3 more, listed in full on the page. ## Agentic access (1) - **Usgs Water Agentic Access** — 284 operations · 35 acting ## Security (2) - **Usgs Water Authentication** — apiKey · 2 schemes - **Usgs Water Domain Security** — TLSv1.2 · HSTS · DNSSEC · DMARC ## Plans (1) - **Usgs Water Plans** ## Tags Water, Streamflow, Groundwater, Water Quality, Hydrology, Environmental, USGS, NWIS, Government, Open Data, OGC --- Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/usgs-water/). Scores are computed from the provider's own public artifacts under a published rubric.