USGS Groundwater Information
New & Noteworthy
USGS Groundwater Watch
USGS maintains a network of active wells to provide basic statistics about groundwater levels.
USGS in Your State
USGS Water Science Centers are located in each state.
Other USGS Water Science Areas
RORA: The recession-curve-displacement method for estimating recharge
The computer program RORA estimates groundwater recharge using the recession-curve-displacement method. The method is based on the change in total potential groundwater discharge that is caused by each recharge event.
This web site includes information about the use of the RORA computer program for analyzing a streamflow record. The version at this site will read streamflow data in the format that is available from USGS web sites.
The user's manual does not include complete explanation of the computer program; the program user is referred to the documentation report (first item below). Additional information is also provided below.
The following resources may also be of use:
Related Software: Groundwater Toolbox
RORA users may also be interested in the Groundwater Toolbox, a graphical and mapping interface for analysis of hydrologic data. The Groundwater Toolbox has several methods for the analysis of streamflow data. These methods include six hydrograph-separation techniques — the Base-Flow Index (BFI Standard and Modified), HYSEP (Fixed Interval, Sliding Interval, and Local Minimum), and PART methods — and the RORA recession-curve displacement method and associated RECESS program to estimate groundwater recharge from streamflow data.
Point of Contact
Support is provided for correcting bugs and clarification of how RORA is intended to work. Only limited assistance can be provided for applying RORA to specific problems. Comments and questions can be sent to Paul Barlow.
Other USGS Groundwater Software
The USGS develops groundwater , water-quality, surface-water, and other water-resources software for use by the USGS in fulfilling its mission. Most of this software is available online for download at no charge.
Disclaimers and Notices
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.
Note: Some or all of this information is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of the free Adobe Reader from the Adobe web site. Visit https://www.adobe.com/accessibility/ for free tools that allow visually impaired users to read PDF files.