The Groundwater Toolbox: A Graphical and Mapping Interface for Analysis of Hydrologic Data

Release Date:

Overview of The Groundwater Toolbox

Flow-duration curves for measured streamflow and estimated base flow and runoff in the Groundwater Toolbox.

Flow-duration curves for measured streamflow and estimated base flow and runoff for Pawcatuck River at Wood River Junction, Rhode Island, 1971-2000, using hydrograph-separation methods provided in the Groundwater Toolbox.​​​​​​​

The Groundwater Toolbox is a graphical and mapping interface for analysis of hydrologic data. The software is a customized interface built on the non-proprietary, open-source MapWindow geographic information system software in a Microsoft Windows computing environment. The Groundwater Toolbox allows for the retrieval of hydrologic time-series data (streamflow, groundwater levels, and precipitation) from the USGS National Water Information System; preprocessed meteorological data from the National Oceanic and Atmospheric Administration National Climatic Data Center also are available with the Groundwater Toolbox.

The Groundwater Toolbox has several methods for the analysis of streamflow-hydrograph data. These methods include: 

  • six graphical hydrograph-separation techniques — the Base-Flow Index (BFI Standard and Modified), HYSEP (Fixed Interval, Sliding Interval, and Local Minimum) and PART methods; 
  • two digital filtering techniques (the SWAT Bflow and Eckhardt approaches); and 
  • the RORA recession-curve displacement method and associated RECESS program to estimate groundwater recharge from streamflow data.

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Download Current Version of The Groundwater Toolbox

Users are encouraged to read documents that are provided in the 'docs' directory of this software distribution.


Documentation for The Groundwater Toolbox

Barlow, P.M., Cunningham, W.L., Zhai, Tong, and Gray, Mark, 2014, U.S. Geological Survey Groundwater Toolbox, a graphical and mapping interface for analysis of hydrologic data (version 1.0): User guide for estimation of base flow, runoff, and groundwater recharge from streamflow data: U.S. Geological Survey Techniques and Methods, book 3, chap. B10, 27 p.

This report is a user's guide for the streamflow-hydrograph analysis methods provided with version 1.0 of the Groundwater Toolbox.


How to Cite The Groundwater Toolbox

This USGS software has two citations associated with it.

  1. The report citation is for the original report or article documenting the underlying theory, methods, instructions, and (or) applications at the time the initial version of the software was released. This digital object identifier (DOI) is for the report.
  2. The software release citation is for the software/code itself (now referred to by USGS as a "Software Release") and references a specific version of the code and associated release date. This DOI links to the code.

In instances where an author is citing use of this software, it would be appropriate to cite both the report documenting the code and the specific software release version that was used.

Report Citation for Groundwater Toolbox Shown Above

Software/Code Citation for Groundwater Toolbox

Barlow, P.M., Cunningham, W.L., Zhai, Tong, and Gray, Mark, 2017, U.S. Geological Survey Groundwater Toolbox version 1.3.1, a graphical and mapping interface for analysis of hydrologic data: U.S. Geological Survey Software Release, 26 May 2017,


Other USGS Software

Additional USGS software can be found on our Water Resources Applications Software page.


Software License and Purchase Information

This software is a product of the U.S. Geological Survey, which is part of the U.S. Government.


This software is freely distributed. There is no fee to download and (or) use this software.


Users do not need a license or permission from the USGS to use this software. Users can download and install as many copies of the software as they need.

Public Domain

As a work of the United States Government, this USGS product is in the public domain within the United States. You can copy, modify, distribute, and perform the work, even for commercial purposes, all without asking permission. Additionally, USGS waives copyright and related rights in the work worldwide through CC0 1.0 Universal Public Domain Dedication ( ).



This software has been approved for release by the U.S. Geological Survey (USGS). Although the software has been subjected to rigorous review, the USGS reserves the right to update the software as needed pursuant to further analysis and review. 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. Furthermore, the software is released on condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use. Also refer to the USGS Water Resources Software User Rights Notice for complete use, copyright, and distribution information.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.