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.
USGS Water Services publishes 44 API contracts indexed on the APIs.io network, including Agency Codes API, Altitude Datums API, Aquifer Codes API, and 41 more. Tagged areas include Water, Streamflow, Groundwater, Water Quality, and Hydrology.
The USGS Water Services catalog on APIs.io includes 2 JSON-LD contexts and 1 Spectral governance ruleset.
USGS Water Services’ developer surface includes authentication, documentation, signup flow, and 12 more developer resources.
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Provides near real-time water data — streamflow, gage height, temperature, specific conductance, and hundreds of other parameters — from thousands of USGS monitoring sites. Valu...
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...
Searches and retrieves metadata for millions of USGS hydrologic data collection sites including streams, springs, wells, lakes, reservoirs, estuaries, and glaciers. Filtering op...
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...
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...
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, ...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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. ...
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...
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...
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...
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...
These APIs provide OGC-compliant interfaces to USGS water data, letting you download continuous sensor measurements, discrete field measurements, metadata about monitoring locat...
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...
Daily data and continuous measurements are grouped into time series, which represent a collection of observations of a single parameter, potentially aggregated using a standard ...
The ISO 8601 standard defines time zone offsets as a numerical value added to a local time to convert it to Coordinated Universal Time (UTC), either as +hh:mm or -hh:mm, or repr...
The code that best describes the topographic setting in which the site is located. Topographic setting refers to the geomorphic features in the vicinity of the site.
Not yet checked against USGS Water Services's own pricing page. Compiled by API Evangelist on 2026-06-13 from api.waterdata.usgs.gov/signup/; confirm before you rely on a figure. A free plan or tier is listed.
aid: usgs-water
name: USGS Water Services
description: 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.
type: Index
deliveryModel:
model: saas
open_source: false
commercial: true
callable_host: true
label: Hosted service · you call their endpoint
confidence: high
source:
- openapi
- pricing
generated: '2026-08-28'
method: derived
accessModel:
pricing: free
onboarding: open
trial: false
try_now: true
public: true
gated: none
gated_source:
- onboarding
label: Free · Open access
confidence: medium
source:
- plans
- authentication
- security
generated: '2026-11-06'
method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/usgs-water.png
access: Public
created: '2026-06-13'
modified: '2026-06-13'
position: Producing
url: https://raw.githubusercontent.com/api-evangelist/usgs-water/refs/heads/main/apis.yml
specificationVersion: '0.23'
tags:
- Water
- Streamflow
- Groundwater
- Water Quality
- Hydrology
- Environmental
- USGS
- NWIS
- Government
- Open Data
- OGC
apis:
- aid: usgs-water:instantaneous-values
name: USGS Instantaneous Values Service
description: Provides near real-time water data — streamflow, gage height, temperature, specific conductance, and hundreds
of other parameters — from thousands of USGS monitoring sites. Values are typically recorded every 15 minutes and transmitted
hourly. Data is available from October 1, 2007 onwards and is marked provisional until reviewed.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- Real-Time
- Streamflow
- Gage Height
- Water Parameters
- Time Series
properties:
- type: Documentation
url: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
- type: Website
url: https://waterservices.usgs.gov/
- aid: usgs-water:daily-values
name: USGS Daily Values Service
description: 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. Supports WaterML 1.1, WaterML 2.0, RDB (tab-delimited), and JSON
output formats.
humanURL: https://waterservices.usgs.gov/docs/dv-service/daily-values-service-details/
baseURL: https://waterservices.usgs.gov/nwis/dv/
tags:
- Daily Values
- Historical Data
- Streamflow
- Hydrology
- WaterML
properties:
- type: Documentation
url: https://waterservices.usgs.gov/docs/dv-service/daily-values-service-details/
- type: Website
url: https://waterservices.usgs.gov/
- aid: usgs-water:site-service
name: USGS Site Service
description: Searches and retrieves metadata for millions of USGS hydrologic data collection sites including streams, springs,
wells, lakes, reservoirs, estuaries, and glaciers. Filtering options include site number, state, HUC, bounding box, county,
site type, and parameter codes. Outputs include tab-delimited, KML, and GeoJSON.
humanURL: https://waterservices.usgs.gov/docs/site-service/site-service-details/
baseURL: https://waterservices.usgs.gov/nwis/site/
tags:
- Site Metadata
- Monitoring Locations
- Geospatial
- NWIS
properties:
- type: Documentation
url: https://waterservices.usgs.gov/docs/site-service/site-service-details/
- type: Website
url: https://waterservices.usgs.gov/
- aid: usgs-water:statistics-service
name: USGS Statistics Service
description: 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 sites per request and returns data in RDB tab-delimited format.
humanURL: https://waterservices.usgs.gov/docs/statistics/statistics-details/
baseURL: https://waterservices.usgs.gov/nwis/stats/
tags:
- Statistics
- Percentiles
- Historical
- Streamflow
- Approved Data
properties:
- type: Documentation
url: https://waterservices.usgs.gov/docs/statistics/statistics-details/
- type: Website
url: https://waterservices.usgs.gov/
- aid: usgs-water:groundwater-levels
name: USGS Groundwater Levels Service
description: 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 RDB format. For automated real-time groundwater data,
the Instantaneous Values Service should be used.
humanURL: https://waterservices.usgs.gov/docs/groundwater-levels/groundwater-levels-details/
baseURL: https://waterservices.usgs.gov/nwis/gwlevels/
tags:
- Groundwater
- Water Levels
- Wells
- Aquifers
- Historical
properties:
- type: Documentation
url: https://waterservices.usgs.gov/docs/groundwater-levels/groundwater-levels-details/
- type: Website
url: https://waterservices.usgs.gov/
- aid: usgs-water:water-quality-portal
name: Water Quality Portal (WQP) API
description: 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, chemistry results, biological metrics, activity data,
and detection limits. Supports spatial, temporal, characteristic, and organizational filters. Output formats include CSV,
TSV, XLSX, XML, GeoJSON, KML, and KMZ.
humanURL: https://www.waterqualitydata.us/webservices_documentation/
baseURL: https://www.waterqualitydata.us/data/
tags:
- Water Quality
- EPA
- Chemistry
- Biology
- Monitoring
- Multi-Agency
properties:
- type: Documentation
url: https://www.waterqualitydata.us/webservices_documentation/
- type: Website
url: https://www.waterqualitydata.us/
- aid: usgs-water:statistics-next-gen
name: USGS Water Data Statistics API
description: 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 WaterServices statistics endpoint.
humanURL: https://api.waterdata.usgs.gov/statistics/v0/docs
baseURL: https://api.waterdata.usgs.gov/statistics/v0/
tags:
- Statistics
- Next Generation
- Time Series
properties:
- type: Documentation
url: https://api.waterdata.usgs.gov/statistics/v0/docs
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-agency-codes-api
name: USGS Water Services Agency Codes API
description: 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 Information System (NWIS).
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- agency-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-agency-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-altitude-datums-api
name: USGS Water Services Altitude Datums API
description: 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 Geodetic Vertical Datum of 1929) and NAVD88 are the
only datums that can be converted on output. NWIS uses the North American Vertical Datum Conversions (VERTCON) of the
National Geodetic Survey to convert from NGVD29 to NAVD88 or vice versa. Conversions to or from other vertical datums
are not available.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- altitude-datums
properties:
- type: OpenAPI
url: openapi/usgs-water-altitude-datums-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-aquifer-codes-api
name: USGS Water Services Aquifer Codes API
description: 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 character abbreviation for the geologic unit or aquifer name).
For the age of formation (aquifer age), generally the smaller the number represents the younger the geohydrologic unit.
Aquifer names and the definition of an aquifer can be very subjective. One rock unit may be called different aquifer names
by different people. Local aquifers and layered aquifers are often grouped into larger named regional aquifers or aquifer
systems. For example, the National Northern Atlantic Coastal Plain aquifer system (National aquifer) consists of five
layered regional aquifers. Each regional aquifer is divided into two or more aquifers which may have a different name
in each of the states in which the aquifer is found.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- aquifer-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-aquifer-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-aquifer-types-api
name: USGS Water Services Aquifer Types API
description: 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 referred to as unconfined (or water-table) aquifers. Where
water completely fills an aquifer that is overlain by a confining bed, the aquifer is referred to as a confined (or artesian)
aquifer. When a confined aquifer is penetrated by a well, the water level in the well will rise above the top of the aquifer
(but not necessarily above land surface).
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- aquifer-types
properties:
- type: OpenAPI
url: openapi/usgs-water-aquifer-types-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-channel-measurements-api
name: USGS Water Services Channel Measurements API
description: Channel measurements taken as part of streamflow field measurements.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- channel-measurements
properties:
- type: OpenAPI
url: openapi/usgs-water-channel-measurements-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-citations-api
name: USGS Water Services Citations API
description: Citations associated with water measurement methods.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- Citations
tags_raw:
- citations
properties:
- type: OpenAPI
url: openapi/usgs-water-citations-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-combined-metadata-api
name: USGS Water Services Combined Metadata API
description: This endpoint combines metadata from timeseries and field measurements collections by site.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- combined-metadata
properties:
- type: OpenAPI
url: openapi/usgs-water-combined-metadata-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-continuous-api
name: USGS Water Services Continuous API
description: 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 on the specific monitoring location, the data may
be transmitted automatically via telemetry and be available on WDFN within minutes of collection, while other times the
delivery of data may be delayed if the monitoring location does not have the capacity to automatically transmit data.
Continuous data are described by parameter name and parameter code (pcode). These data might also be referred to as "instantaneous
values" or "IV".
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags: []
tags_raw:
- continuous
properties:
- type: OpenAPI
url: openapi/usgs-water-continuous-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-coordinate-accuracy-codes-api
name: USGS Water Services Coordinate Accuracy Codes API
description: Appropriate code on the schedule to indicate the accuracy of the latitude-longitude values.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- coordinate-accuracy-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-coordinate-accuracy-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-coordinate-datum-codes-api
name: USGS Water Services Coordinate Datum Codes API
description: Horizontal datum code for the latitude/longitude coordinates. There are currently more than 300 horizontal
datums available for entry.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- coordinate-datum-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-coordinate-datum-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-coordinate-method-codes-api
name: USGS Water Services Coordinate Method Codes API
description: Methods used to determine latitude-longitude values.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- coordinate-method-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-coordinate-method-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-counties-api
name: USGS Water Services Counties API
description: 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 associated Country and State.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- counties
properties:
- type: OpenAPI
url: openapi/usgs-water-counties-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-countries-api
name: USGS Water Services Countries API
description: FIPS country codes and names.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- Countries
tags_raw:
- countries
properties:
- type: OpenAPI
url: openapi/usgs-water-countries-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-daily-api
name: USGS Water Services Daily API
description: 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 collected manually at the monitoring location once each day.
With improved availability of computer storage and automated transmission of data, the daily data published today are
generally a statistical summary or metric of the continuous data collected each day, such as the daily mean, minimum,
or maximum value. Daily data are automatically calculated from the continuous data of the same parameter code and are
described by parameter code and a statistic code. These data have also been referred to as “daily values” or “DV”.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- Daily
tags_raw:
- daily
properties:
- type: OpenAPI
url: openapi/usgs-water-daily-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-field-measurements-api
name: USGS Water Services Field Measurements API
description: Field measurements are physically measured values collected during a visit to the monitoring location. Field
measurements consist of measurements of gage height and discharge, and readings of groundwater levels, and are primarily
used as calibration readings for the automated sensors collecting continuous data. They are collected at a low frequency,
and delivery of the data in WDFN may be delayed due to data processing time.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- field-measurements
properties:
- type: OpenAPI
url: openapi/usgs-water-field-measurements-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-field-measurements-metadata-api
name: USGS Water Services Field Measurements Metadata API
description: This endpoint provides metadata about field measurement collections, including when the earliest and most recent
observations for a parameter occurred at a monitoring location and its units.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- field-measurements-metadata
properties:
- type: OpenAPI
url: openapi/usgs-water-field-measurements-metadata-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-hydrologic-unit-codes-api
name: USGS Water Services Hydrologic Unit Codes API
description: '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 United States is divided and sub-divided into successively
smaller hydrologic units which are classified into four levels: regions, sub-regions, accounting units, and cataloging
units. Each unit consists of two to eight digits based on the four levels of classification in the hydrologic unit system.
Additional information can be found at <https://water.usgs.gov/GIS/huc.html>.'
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- hydrologic-unit-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-hydrologic-unit-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-latest-continuous-api
name: USGS Water Services Latest Continuous API
description: 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 location. They are collected at a high frequency and often
at a fixed 15-minute interval. Depending on the specific monitoring location, the data may be transmitted automatically
via telemetry and be available on WDFN within minutes of collection, while other times the delivery of data may be delayed
if the monitoring location does not have the capacity to automatically transmit data. Continuous data are described by
parameter name and parameter code. These data might also be referred to as "instantaneous values" or "IV"
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- latest-continuous
properties:
- type: OpenAPI
url: openapi/usgs-water-latest-continuous-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-latest-daily-api
name: USGS Water Services Latest Daily API
description: 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 collected manually at the monitoring location once each day.
With improved availability of computer storage and automated transmission of data, the daily data published today are
generally a statistical summary or metric of the continuous data collected each day, such as the daily mean, minimum,
or maximum value. Daily data are automatically calculated from the continuous data of the same parameter code and are
described by parameter code and a statistic code. These data have also been referred to as “daily values” or “DV”.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- latest-daily
properties:
- type: OpenAPI
url: openapi/usgs-water-latest-daily-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-latest-field-measurements-api
name: USGS Water Services Latest Field Measurements API
description: Field measurements are physically measured values collected during a visit to the monitoring location. Field
measurements consist of measurements of gage height and discharge, and readings of groundwater levels, and are primarily
used as calibration readings for the automated sensors collecting continuous data. They are collected at a low frequency,
and delivery of the data in WDFN may be delayed due to data processing time.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- latest-field-measurements
properties:
- type: OpenAPI
url: openapi/usgs-water-latest-field-measurements-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-medium-codes-api
name: USGS Water Services Medium Codes API
description: 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 have data for several media, such as water, bottom
sediment, fish tissue, and others.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- medium-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-medium-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-method-categories-api
name: USGS Water Services Method Categories API
description: Categorical standards for methods describing the associated data's appropriateness for an intended use.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- method-categories
properties:
- type: OpenAPI
url: openapi/usgs-water-method-categories-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-method-citations-api
name: USGS Water Services Method Citations API
description: Citation identifiers for water measurement methods.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- method-citations
properties:
- type: OpenAPI
url: openapi/usgs-water-method-citations-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-methods-api
name: USGS Water Services Methods API
description: 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. Method codes are associated with one or many parameter
codes.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags: []
tags_raw:
- methods
properties:
- type: OpenAPI
url: openapi/usgs-water-methods-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-monitoring-locations-api
name: USGS Water Services Monitoring Locations API
description: Location information is basic information about the monitoring location including the name, identifier, agency
responsible for data collection, and the date the location was established. It also includes information about the type
of location, such as stream, lake, or groundwater, and geographic information about the location, such as state, county,
latitude and longitude, and hydrologic unit code (HUC).
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- Monitoring Locations
tags_raw:
- monitoring-locations
properties:
- type: OpenAPI
url: openapi/usgs-water-monitoring-locations-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-national-aquifer-codes-api
name: USGS Water Services National Aquifer Codes API
description: 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 used as a source of potable water.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- national-aquifer-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-national-aquifer-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-parameter-codes-api
name: USGS Water Services Parameter Codes API
description: '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 information about the sampling matrix, fraction, and methods
used to measure the constituent. Some parameters are fixed-value (fxd) numeric codes having textual meaning (for example:
parameter code 00041 is a weather code parameter, code of 60 means rain), but more commonly represent a numeric value
for chemical, physical, or biological data.'
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- parameter-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-parameter-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-peaks-api
name: USGS Water Services Peaks API
description: 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 annual peak flow value may not occur at the same time
the maximum water level occurs due to conditions such as backwater, tidal fluctuations, etc.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- peaks
properties:
- type: OpenAPI
url: openapi/usgs-water-peaks-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-reliability-codes-api
name: USGS Water Services Reliability Codes API
description: Code indicating the reliability of the data available for the site.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- reliability-codes
properties:
- type: OpenAPI
url: openapi/usgs-water-reliability-codes-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
- aid: usgs-water:usgs-water-server-api
name: USGS Water Services Server API
description: These APIs provide OGC-compliant interfaces to USGS water data, letting you download continuous sensor measurements,
discrete field measurements, metadata about monitoring locations, and more.
humanURL: https://waterservices.usgs.gov/docs/instantaneous-values/instantaneous-values-details/
baseURL: https://waterservices.usgs.gov/nwis/iv/
tags:
- Servers
tags_raw:
- server
properties:
- type: OpenAPI
url: openapi/usgs-water-server-api-openapi.yml
- type: Documentation
url: https://api.waterdata.usgs.gov/docs/
- type: Website
url: https://api.waterdata.usgs.gov/
# --- truncated at 32 KB (37 KB total) ---
# Full source: https://artifacts.apis.io/usgs-water/apis.yml
USGS Water Services API — frequently asked questions
Does USGS Water Services have an API?
Yes. APIs.io lists 44 APIs from USGS Water Services, including USGS Instantaneous Values Service, USGS Daily Values Service and USGS Site Service, and 41 more.
Is there an OpenAPI specification for the USGS Water Services API?
Yes. APIs.io indexes 36 OpenAPI specifications for USGS Water Services, each linked for download from this page.
How do I authenticate with the USGS Water Services API?
USGS Water Services uses bearer-token authentication (apiKey · 2 schemes). The details are profiled on APIs.io as Usgs Water Authentication.
How much does the USGS Water Services API cost?
APIs.io lists 2 pricing plans for USGS Water Services, with each plan's price, limits and inclusions under Pricing on this page.
Is the USGS Water Services API ready for AI agents?
USGS Water Services has a Kin Score of 37.4 out of 100 (thin) and an Agent Readiness score of 21.5 (agent-aware), scored by API Evangelist on 2026-11-06.
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