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.
US Geological Survey - Water Data for the Nation
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"
This is an early version of the continuous endpoint. It is feature-complete and provides access to the full continuous data record, and is being made available as we continue to work on performance improvements. 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".
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”.
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.
Channel measurements taken as part of streamflow field measurements.
This endpoint combines metadata from timeseries and field measurements collections by site.
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.
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 statistic, at a single monitoring location. This endpoint provides metadata about those time series, including their operational thresholds, units of measurement, and when the earliest and most recent observations in a time series occurred.
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).
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).
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.
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.
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).
Appropriate code on the schedule to indicate the accuracy of the latitude-longitude values.
Horizontal datum code for the latitude/longitude coordinates. There are currently more than 300 horizontal datums available for entry.
Methods used to determine latitude-longitude values.
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.
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>.
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.
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.
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.
Code indicating the reliability of the data available for the site.
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 collection sites. All sites have a primary site type, and may additionally have a secondary site type that further describes the location.
State name or territory. Includes U.S. states and foreign entities classified under FIPS as 'Principal Administrative Divisions'.
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.
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 represented by the letter Z to explicitly indicate UTC. For example, +05:30 means 5 hours and 30 minutes ahead of UTC, while -08:00 means 8 hours behind UTC. The offset Z specifically signifies UTC.