dataretrieval: Download hydrologic data

Latest Announcements

📣 11/24/2025: dataretrieval now features the new waterdata module, which provides access to USGS's modernized Water Data APIs. The Water Data API endpoints include daily values, instantaneous values, field measurements, time series metadata, and discrete water quality data from the Samples database. This new module will eventually replace the nwis module, which provides access to the legacy NWIS Water Services.

Important: Users of the Water Data APIs are strongly encouraged to obtain an API key for higher rate limits and greater access to USGS data. Register for an API key and set it as an environment variable:

import os
os.environ["API_USGS_PAT"] = "your_api_key_here"

Check out the NEWS file for all updates and announcements.

What is dataretrieval?

dataretrieval simplifies the process of loading hydrologic data into Python. Like the original R version dataRetrieval, it retrieves major U.S. Geological Survey (USGS) hydrology data types available on the Web, as well as data from the Water Quality Portal (WQP) and Network Linked Data Index (NLDI).

Installation

Install dataretrieval using pip:

pip install dataretrieval

Or using conda:

conda install -c conda-forge dataretrieval

To install the "main" branch directly from GitHub, use:

pip install git+https://github.com/DOI-USGS/dataretrieval-python.git

Usage Examples

Water Data API (Recommended - Modern USGS Data)

The waterdata module provides access to modern USGS Water Data APIs.

The example below retrieves daily streamflow data for a specific monitoring location for water year 2025, where a "/" between two dates in the "time" input argument indicates a desired date range:

import dataretrieval.waterdata as waterdata

# Get daily streamflow data (returns DataFrame and metadata)
df, metadata = waterdata.get_daily(
    monitoring_location_id='USGS-01646500', 
    parameter_code='00060',  # Discharge
    time='2024-10-01/2025-09-30'
)

print(f"Retrieved {len(df)} records")
print(f"Site: {df['monitoring_location_id'].iloc[0]}")
print(f"Mean discharge: {df['value'].mean():.2f} {df['unit_of_measure'].iloc[0]}")

Fetch daily discharge data for multiple sites from a start date to present using the following code:

df, metadata = waterdata.get_daily(
    monitoring_location_id=["USGS-13018750","USGS-13013650"],
    parameter_code='00060',
    time='2024-10-01/..'
)

print(f"Retrieved {len(df)} records")

The following example downloads location information for all monitoring locations that are categorized as stream sites in the state of Maryland:

# Get monitoring location information
locations, metadata = waterdata.get_monitoring_locations(
    state_name='Maryland',
    site_type_code='ST'  # Stream sites
)

print(f"Found {len(locations)} stream monitoring locations in Maryland")

Visit the API Reference for more information and examples on available services and input parameters.

NEW: This new module implements logging in which users can view the URL requests sent to the USGS Water Data APIs and the number of requests they have remaining each hour. These messages can be helpful for troubleshooting and support. To enable logging in your python console or notebook:

import logging
logging.basicConfig(level=logging.INFO)

To log messages to a file, you can specify a filename in the basicConfig call:

logging.basicConfig(filename='waterdata.log', level=logging.INFO)

NWIS Legacy Services (Deprecated but still functional)

The nwis module accesses legacy NWIS Water Services:

import dataretrieval.nwis as nwis

# Get site information
info, metadata = nwis.get_info(sites='01646500')
    
print(f"Site name: {info['station_nm'].iloc[0]}")

# Get daily values
dv, metadata = nwis.get_dv(
  sites='01646500',
  start='2024-10-01',
  end='2024-10-02',
  parameterCd='00060',
)
    
print(f"Retrieved {len(dv)} daily values")

Water Quality Portal (WQP)

Access water quality data from multiple agencies:

import dataretrieval.wqp as wqp

# Find water quality monitoring sites
sites = wqp.what_sites(
    statecode='US:55',  # Wisconsin
    siteType='Stream'
)

print(f"Found {len(sites)} stream monitoring sites in Wisconsin")

# Get water quality results
results = wqp.get_results(
    siteid='USGS-05427718',
    characteristicName='Temperature, water'
)

print(f"Retrieved {len(results)} temperature measurements")

Network Linked Data Index (NLDI)

Discover and navigate hydrologic networks:

import dataretrieval.nldi as nldi

# Get watershed basin for a stream reach
basin = nldi.get_basin(
    feature_source='comid',
    feature_id='13293474'  # NHD reach identifier  
)

print(f"Basin contains {len(basin)} feature(s)")

# Find upstream flowlines
flowlines = nldi.get_flowlines(
    feature_source='comid',
    feature_id='13293474',
    navigation_mode='UT',  # Upstream tributaries
    distance=50  # km
)

print(f"Found {len(flowlines)} upstream tributaries within 50km")

Available Data Services

Modern USGS Water Data APIs (Recommended)

• Daily values: Daily statistical summaries (mean, min, max)
• Field measurements: Discrete measurements from field visits
• Monitoring locations: Site information and metadata
• Time series metadata: Information about available data parameters
• Latest daily values: Most recent daily statistical summary data
• Latest instantaneous values: Most recent high-frequency continuous data
• Samples data: Discrete USGS water quality data
• Instantaneous values (COMING SOON): High-frequency continuous data

Legacy NWIS Services (Deprecated)

• Daily values (dv): Legacy daily statistical data
• Instantaneous values (iv): Legacy continuous data
• Site info (site): Basic site information
• Statistics (stat): Statistical summaries
• Discharge peaks (peaks): Annual peak discharge events
• Discharge measurements (measurements): Direct flow measurements

Water Quality Portal

• Results: Water quality analytical results from USGS, EPA, and other agencies
• Sites: Monitoring location information
• Organizations: Data provider information
• Projects: Sampling project details

Network Linked Data Index (NLDI)

• Basin delineation: Watershed boundaries for any point
• Flow navigation: Upstream/downstream network traversal
• Feature discovery: Find monitoring sites, dams, and other features
• Hydrologic connectivity: Link data across the stream network

More Examples

Explore additional examples in the demos directory, including Jupyter notebooks demonstrating advanced usage patterns.

Getting Help

• Issue tracker: Report bugs and request features at https://github.com/USGS-python/dataretrieval/issues
• Documentation: Full API documentation available in the source code docstrings

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for development guidelines.

Acknowledgments

This material is partially based upon work supported by the National Science Foundation (NSF) under award 1931297. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF.

Disclaimer

This software is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The software has not received final approval by the U.S. Geological Survey (USGS). No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. The software is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the software.

Citation

Hodson, T.O., Hariharan, J.A., Black, S., and Horsburgh, J.S., 2023, dataretrieval (Python): a Python package for discovering and retrieving water data available from U.S. federal hydrologic web services: U.S. Geological Survey software release, https://doi.org/10.5066/P94I5TX3.