USGS - science for a changing world

USGS Groundwater Information

*  Home *  Data & Information *  Publications *  Methods & Modeling *  Selected Topics *  Programs *  About *  Contact Us

New & Noteworthy

Press Releases RSS

USGS Groundwater Watch

USGS maintains a network of active wells to provide basic statistics about groundwater levels.

 [Image: USGS active water level wells location map.]

USGS in Your State

USGS Water Science Centers are located in each state.

 [Map: There is a USGS Water Science Center office in each State.] Washington Oregon California Idaho Nevada Montana Wyoming Utah Colorado Arizona New Mexico North Dakota South Dakota Nebraska Kansas Oklahoma Texas Minnesota Iowa Missouri Arkansas Louisiana Wisconsin Illinois Mississippi Michigan Indiana Ohio Kentucky Tennessee Alabama Pennsylvania West Virginia Georgia Florida Caribbean Alaska Hawaii and Pacific Islands New York Vermont New Hampshire Maine Massachusetts South Carolina North Carolina Rhode Island Virginia Connecticut New Jersey Maryland-Delaware-D.C.

Other USGS Water Science Areas

Water Software > Groundwater Software > MODFLOW and Related Programs > GSFLOW

GSFLOW: coupled groundwater and surface-water flow model

Overview of GSFLOW

GSFLOW is a coupled Groundwater and Surface-water FLOW model based on the integration of the USGS Precipitation-Runoff Modeling System (PRMS) and the USGS Modular Groundwater Flow Model (MODFLOW). GSFLOW was developed to simulate coupled groundwater/surface-water flow in one or more watersheds by simultaneously simulating flow across the land surface, within subsurface saturated and unsaturated materials, and within streams and lakes. Climate data consisting of measured or estimated precipitation, air temperature, and solar radiation, as well as groundwater stresses (such as withdrawals) and boundary conditions are the driving factors for a GSFLOW simulation.

GSFLOW operates on a daily time step. In addition to the MODFLOW variable-length stress period used to specify changes in stress or boundary conditions, GSFLOW uses internal daily stress periods for adding recharge to the water table and calculating flows to streams and lakes.

GSFLOW can be used to evaluate the effects of such factors as land-use change, climate variability, and groundwater withdrawals on surface and subsurface flow for watersheds that range from a few square kilometers to several thousand square kilometers, and for time periods that range from months to several decades.

GSFLOW Information and Downloads

[ Image: Cover of software documentation report. ]

Software Downloads

The current release of GSFLOW is version 1.1.6, released March 28, 2013. Users are encouraged to read the documents that are provided in the 'doc' directory of this software distribution.

Documentation of GSFLOW

Example USGS Applications of GSFLOW

Allander, K.K., Niswonger, R.N., and Jeton, A.E., 2014, Simulation of the Lower Walker River Basin hydrologic system, west-central Nevada, Using PRMS and MODFLOW models: U.S. Geological Survey Scientific Investigations Report 2014-5190, 93 p.,

Ely, D.M., and Kahle, S.C., 2012, Simulation of groundwater and surface-water resources and evaluation of water-management alternatives for the Chamokane Creek basin, Stevens County, Washington: U.S. Geological Survey Scientific Investigations Report 2012-5224, 74 p.

Essaid, H.I., and Hill, B.R., 2014, Watershed-scale modeling of streamflow change in incised montane meadows [Link exits the USGS web site]: Water Resources Research, vol. 50, pp. 2657-2678, doi:10.1002/2013WR014420.

Hunt, R.J., Walker, J.F., Selbig, W.R., Westenbroek, S.M., and Regan, R.S., 2013, Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin: U.S. Geological Survey Scientific Investigations Report 2013-5159, 118 p.

Huntington, J.L., and Niswonger, R.G., 2012, Role of surface-water and groundwater interactions on projected summertime streamflow in snow dominated regions: An integrated modeling approach [Link exits the USGS web site]: Water Resources Research, vol. 48, W11524, doi: 10.1029/2012WR012319.

Huntington, J.L., Niswonger, R.G., Rajagopal, S., Zhang, Y., Gardner, M., Morton, C.G., Reeves, D.M., McGraw, D., and Pohll, G.M., 2013, Integrated hydrologic modeling of Lake Tahoe and Martis Valley mountain block and alluvial systems, Nevada and California [380KB PDF] [Link exits the USGS web site]: Golden, CO, MODFLOW and More 2013 Conference Proceedings, 5 pp.

Mejia, J.F., Huntington, Justin, Hatchett, Benjamin, Koracin, Darko, and Niswonger, R.G., 2012, Linking global climate models to an integrated hydrologic model: Using an individual station downscaling approach [Link exits the USGS web site]: Journal of Contemporary Water Research and Education, issue 147, p. 17-27.

Niswonger, R.G., Allander, K.K., and Jeton, A.E., 2014, Collaborative modelling and integrated decision support system analysis of a developed terminal lake basin: Journal of Hydrology, doi: 10.1016/j.jhydrol.2014.05.043. Avalaible online at or

Tanvir Hassan, S.M., Lubczynski, M.W., Niswonger, R G., and Su, Z., 2014, Surface-groundwater interactions in hard rocks in Sardon Catchment of Western Spain: an integrated modeling approach: Journal of Hydrology, doi: 10.1016/j.jhydrol.2014.05.026. Avalaible online at

Woolfenden, L.R., and Nishikawa, Tracy, eds., 2014, Simulation of groundwater and surface-water resources of the Santa Rosa Plain watershed, Sonoma County, California: U.S. Geological Survey Scientific Investigations Report 2014-5052, 258 p.,

A complete list of publications discussing GSFLOW is also available.


Training Materials

The USGS Modeling of Watershed Systems (MOWS) group has supplemental training and instructional materials available from a 2009 USGS GSFLOW training course:

Point of Contact

Support is provided for correcting bugs and clarification of how GSFLOW is intended to work. Only limited assistance can be provided for applying GSFLOW to specific problems by contacting GSFLOW Help or contacting the Office of Groundwater:

U.S. Geological Survey
Office of Groundwater
411 National Center
12201 Sunrise Valley Drive
Reston, VA 20192

Related USGS Software Resources

USGS computer programs related to GSFLOW include the following:

Other USGS Groundwater Software

The USGS develops groundwater RSS, 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

Please refer to the USGS Software User Rights Notice for complete use, copyright, and distribution information. The USGS provides no warranty, expressed or implied, as to the correctness of the furnished software or the suitability for any purpose. The software has been tested, but as with any complex software, there could be undetected errors. Users who find errors are requested to report them to the USGS.

References to non-USGS products, trade names, and (or) services are provided for information purposes only and do not constitute endorsement or warranty, express or implied, by the USGS, U.S. Department of Interior, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.

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. [Link exits USGS] Visit [Link exits USGS] for free tools that allow visually impaired users to read PDF files.

USGS Home Water Climate and Land Use Change Core Science Systems Ecosystems Energy and Minerals Environmental Health Natural Hazards

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact the USGS Office of Groundwater
Page Last Modified: Wednesday, 17-Dec-2014 12:16:38 EST