Accessing data from the supported databases through their APIs.

Module Contents#

class pygeohydro.waterdata.NWIS#

Access NWIS web service.


More information about query parameters and codes that NWIS accepts can be found at its help webpage.

get_info(queries, expanded=False, fix_names=True)#

Send multiple queries to USGS Site Web Service.

  • queries (dict or list of dict) – A single or a list of valid queries.

  • expanded (bool, optional) – Whether to get expanded site information for example drainage area, default to False.

  • fix_names (bool, optional) – If True, reformat station names and some small annoyances, defaults to True.


geopandas.GeoDataFrame – A correctly typed GeoDataFrame containing site(s) information.


Search for parameter codes by name or number.


NWIS guideline for keywords is as follows:

By default an exact search is made. To make a partial search the term should be prefixed and suffixed with a % sign. The % sign matches zero or more characters at the location. For example, to find all with “discharge” enter %discharge% in the field. % will match any number of characters (including zero characters) at the location.


keyword (str) – Keyword to search for parameters by name of number.


pandas.DataFrame – Matched parameter codes as a dataframe with their description.


>>> from pygeohydro import NWIS
>>> nwis = NWIS()
>>> codes = nwis.get_parameter_codes("%discharge%")
>>> codes.loc[codes.parameter_cd == "00060", "parm_nm"][0]
'Discharge, cubic feet per second'
get_streamflow(station_ids, dates, freq='dv', mmd=False, to_xarray=False)#

Get mean daily streamflow observations from USGS.

  • station_ids (str, list) – The gage ID(s) of the USGS station.

  • dates (tuple) – Start and end dates as a tuple (start, end).

  • freq (str, optional) – The frequency of the streamflow data, defaults to dv (daily values). Valid frequencies are dv (daily values), iv (instantaneous values). Note that for iv the time zone for the input dates is assumed to be UTC.

  • mmd (bool, optional) – Convert cms to mm/day based on the contributing drainage area of the stations. Defaults to False.

  • to_xarray (bool, optional) – Whether to return a xarray.Dataset. Defaults to False.


pandas.DataFrame or xarray.Dataset – Streamflow data observations in cubic meter per second (cms). The stations that don’t provide the requested discharge data in the target period will be dropped. Note that when frequency is set to iv the time zone is converted to UTC.

static retrieve_rdb(url, payloads)#

Retrieve and process requests with RDB format.

  • url (str) – Name of USGS REST service, valid values are site, dv, iv, gwlevels, and stat. Please consult USGS documentation here for more information.

  • payloads (list of dict) – List of target payloads.


pandas.DataFrame – Requested features as a pandas’s DataFrame.

class pygeohydro.waterdata.WBD(layer, outfields='*', crs=4326)#

Access Watershed Boundary Dataset (WBD).


This web service offers Hydrologic Unit (HU) polygon boundaries for the United States, Puerto Rico, and the U.S. Virgin Islands. For more info visit:

  • layer (str, optional) – A valid service layer. Valid layers are:

    • wbdline

    • huc2

    • huc4

    • huc6

    • huc8

    • huc10

    • huc12

    • huc14

    • huc16

  • outfields (str or list, optional) – Target field name(s), default to “*” i.e., all the fields.

  • crs (str, int, or pyproj.CRS, optional) – Target spatial reference, default to EPSG:4326.


Get the full watershed boundary for a given HUC level.


This function is designed for cases where the full watershed boundary is needed for a given HUC level. If only a subset of the HUCs is needed, then use the pygeohydro.WBD class. The full dataset is downloaded from the National Maps’ WBD staged products.


huc_lvl (int) – HUC level, must be even numbers between 2 and 16.


geopandas.GeoDataFrame – The full watershed boundary for the given HUC level.


Get monthly water use for irrigation at HUC12-level for CONUS.


Dataset is retrieved from