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MODFLOW One-Water Hydrologic Flow Model (MF-OWHM)

April 7, 2020


One-Water Hydrologic Flow Model cross section
One-Water Hydrologic Flow Model: A MODFLOW Based Conjunctive-Use Simulation Software (Boyce and others, 2020). (Public domain.)

The MODFLOW One-Water Hydrologic Flow Model (MF-OWHM; Boyce and others, 2020Hanson and others, 2014) is a MODFLOW-2005 based integrated hydrologic model designed for the analysis of conjunctive-use management. The term “integrated” refers to the tight coupling of groundwater flow, surface-water flow, landscape processes, aquifer compaction and subsidence, reservoir operations, and conduit (karst) flow. This fusion results in a simulation software capable of addressing water-use and sustainability problems, including conjunctive-use, water-management, water-food-security, and climate-crop-water scenarios.  


  • Process-based simulation 
    • Saturated groundwater flow(three-dimensional) 
    • Surface-water flow(one- and two-dimensional) 
      • Stream and river flow 
      • Lake and reservoir storage 
    • Landscape simulation and irrigated agriculture 
      • Land-use and crop simulation 
      • Root uptake of groundwater 
      • Precipitation 
      • Actual evapotranspiration 
      • Runoff 
      • Infiltration 
      • Estimated irrigation demand 
    • Reservoir operations 
    • Aquifer compaction and subsidence by vertical model-grid deformation 
    • Seawater intrusion by a sharp-interface assumption 
    • Karst-aquifer and fractured-bedrock flow 
    • Turbulent and laminar-pipe network flow 
    • Unsaturated groundwater flow (one-dimensional) 
  • Internal linkages among the processes that couple hydraulic head, flow, and deformation. 
  • Redesigned code for 
    • Faster simulation runtime 
    • Increased user-input options 
    • Easier for model updates 
    • Robust error reporting 


For more detailed information, please visit MODFLOW One-Water Hydrologic Flow Model—Conjunctive Use Simulation Software (MF-OWHM)



Program History  |  Downloads & Documentation  |  MODFLOW-OWHM Process & Packages Support  |  Superseded Versions


Program History

Version Highlights

MF-OWHM v2.00 is the second major release of MF-OWHM. This version involved a total rewrite of the Farm Process (FMP), inclusion of the Conduit Flow Process (CFP Shoemaker and others, 2008), and modifications that improved all the base MODFLOW packages. 

MF-OWHM v1.00 was the first major release of MF-OWHM that is a unification of the many separate versions of MODFLOW that have evolved for various classes of hydrologic issues. In addition to this, modifications were made to the MF2005 source code that improve stability, accuracy and make the resulting software more "user friendly". MF-OWHM v1.00 is now considered legacy code with minimal support. 

Version Information and Notes

MF-OWHM v2.00.00 04/7/2020 is the initial release of version 2. 

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


Downloads and Documentation

General Information

Current Release: v.2.00.00, 04/7/2020

The MF-OWHM release comes in a variety of different installation options that depend on your platform or desired level of information included (i.e. full documentation or just the executable). Within the distribution the word Win and Nix are used to delineate between MS Windows and GNU Unix, respectively.   

If you wish to be included in our email list to be notified when updates occur, please send an email to with the word "add" in the title.


Software Downloads

Users are highly encouraged to read through the documentation located in the "doc" folder. If you use of this software please cite the USGS Techniques and Methods 6-A60 One-Water Hydrologic Flow Model (MODFLOW-OWHM) report (2020) in any associated publications and reports.

Please Note: Pre-compiled unix/linux binaries may not work on all unix systems. If you are having issues, try useing the makefile and compile OWHM.


Documentation of MF-OWHM

  • Report: MF-OWHM2 and One-Water Hydrologic Flow Model (MODFLOW-OWHM) are the official USGS reports that describes the theory and input instructions at the time the distributions were first released. If you use of this software please cite the reports in any associated publications and reports. 

    The suggested citations are as follows:

    Boyce, S.E., Hanson, R.T., Ferguson, I., Schmid, W., Henson, W., Reimann, T., Mehl, S.M., and Earll, M.M., 2020, One-Water Hydrologic Flow Model: A MODFLOW Based Conjunctive Use and Integrated Hydrologic Flow Model (2020): U.S. Geological Survey Techniques and Methods 6-A60, 435 p.

    Hanson, R.T., Boyce, S.E., Schmid, Wolfgang, Hughes, J.D., Mehl, S.M., Leake, S.A., Maddock, Thomas, III, and Niswonger, R.G., 2014, One-Water Hydrologic Flow Model (MODFLOW-OWHM): U.S. Geological Survey Techniques and Methods 6-A51, 120 p.,



MODFLOW-OWHM Process and Packages Support

The Online Guide to MODFLOW-OWHM (v1) provides quick access to the key documentation for MODFLOW-OWHM processes and packages:

  • Report: The official USGS report describes the theory and input instructions at the time the package or process was first released.
  • Online Guide: Packages and processes often evolve over time. The Online User's Guide includes the most up-to-date input instructions and related details.


Functionality Package or Process Name Short Description Online Guide
NAM Name file that lists all packages in use Not a , but loaded at start of simulation to declare s and processes used by user’s model application.  
LGR Local Grid Refinement    LGR Online Help
LIST Listing file Contains transcript of  output, warnings, and errors.  
WARN Warning file Contains a transcript of  warnings and errors that are raised and written to the listing file.  
BAS Basic  Defines global options, active model cells, and initial head. BAS Online Help
DIS Discretization  Specifies model time and space discretization. DIS Online Help
OC Output Control Specifies writing of output to list and cell-by-cell flow file. OC Online Help
ZONE Zone file Parameter process—specify parameter zones of application. ZONE Online Help
MULT Multiplier file Parameter process—specify parameter multiplication arrays. MULT Online Help
PVAL Parameter Value file Parameter process—specify global parameters. PVAL Online Help
BCF Block-Centered Flow  Defines aquifer flow properties. BCF Online Help
LPF Layer-Property Flow  Defines aquifer flow properties. LPF Online Help
UPW Upstream Weighting Defines aquifer flow properties. UPW Online Help
HUF Hydrogeologic-Unit Flow  Defines aquifer flow properties. HUF Online Help
HFB Horizontal Flow Barrier  Barriers to flow between model cells (for example, faultline or slurry walls). HFB Online Help
UZF Unsaturated-Zone Flow Vertical flow of water through the unsaturated zone to water table. UZF Online Help
SWI2 Seawater Intrusion  Vertically integrated, variable-density groundwater flow and seawater intrusion in coastal multi-aquifer systems. SWI2 Online Help
FMP Farm Process Dynamic simulation of land use, evapotranspiration, surface-water diversions, and estimation of unknown pumpage. FMP Online Help
CFP Conduit Flow Process Simulation of turbulent flow through karst conduits or pipe networks. CFP Online Help
LMT Link-MT3DMS Produces a binary flow file that is used for MT3DMS and MT3D‑USGS for transport simulation. LMT Online Help
BFH Boundary Flow and Head  LGR child model only—couples parent model’s flows and heads to child model. BFH Online Help
CHD Time-Variant Specified-Head Specifies model cells that have a constant head (not recommended for conjunctive use). CHD Online Help
FHB Flow and Head Boundary  Specifies model cells that have a constant head or constant flux in or out. FHB Online Help
RCH Recharge  Specified flux distributed over the dtop of the model domain. RCH Online Help
GHB General Head Boundary  Simulates head-dependent flux boundaries. GHB Online Help
DRN Drain  Simulates head-dependent flux boundaries that remove water from domain if head is above a specified elevation. DRN Online Help
DRT Drain Return Simulates head-dependent flux boundaries that move water from model cell if head is above a specified elevation. DRN Online Help
RIP Riparian Evapotranspiration Simulates evapotranspiration separately for multiple plant functional groups in a single model cell. RIP Online Help
EVT Evapotranspiration  Taken directly from the EVT  description from the MODFLOW documentation. EVT Online Help
ETS Evapotranspiration Segmenteds Simulates evapotranspiration with a user-defined relation between evapotranspiration rate and hydraulic head. ETS Online Help
RES Reservoir  Simulates leakage between a reservoir and the underlying groundwater. RES Online Help
IBS Interbed Storag Simulates compaction of low-permeability interbeds within layers (legacy code—recommended to use SUB instead) (not recommended for conjunctive use). IBS Online Help
SUB Subsidence and Aquifer-System Compaction Simulates drainage; changes in groundwater storage; and compaction of aquifers, interbeds, and confining units that constitute an aquifer system. SUB Online Help
SWT Subsidence for water table aquifers Simulates compaction for changes in water table by including geostatic stresses as a function of water-table elevation. SWT Online Help
RIV River  Simulates head-dependent flux boundaries by specifying a river stage (not recommended for conjunctive use). RIV Online Help
LAK Lake  Simulates lake storage and flow. LAK Online Help
STR Stream  Flow in a stream is routed instantaneously to downstream streams (legacy code—recommended to use SFR instead). STR Online Help
SFR Streamflow-Routing  Simulates streamflow by instantaneously routing to downstream streams and lakes or routed using a kinematic wave equation. SFR Online Help
SWR Surface=Water Routing Process Simulates surface-water routing in 1D and 2D surface-water features and surface-water and groundwater interactions. SWR Online Help
WEL Well (Version 2) Specified flux to model cells in units; revised TABFILE input.  
WEL1 Well (Version 1) Specified flux to model cells in units; original TABFILE input. WEL1 Online Help
MNW1 Multi-node, drawdown-limited well Simulates wells that extend to more than one cell (legacy code—recommended to use MNW2 instead). MNW1 Online Help
MNW2 Multi-node well Simulates “long” wells that are connected to more than one model cell; calculates well head and well potential production. MNW2 Online Help
MNWI Multi-Node Well Information  Provides detailed output from MNW2 wells. MNWI Online Help
HYD HydMod Provides time series of observations from SFR, SUB, and Head. HYDMOD Online Help
GAGE Stream gaging (monitoring) station Provides output for specified SFR segments and LAK lakes. GAG Online Help
HOB Head Observation  Specifies observations of head in aquifer. HOB Online Help
DROB Drain (DRN) Observation  Specifies observations of DRN related flows. DROB Online Help
DRTOB Drain Return (DRT) observation Specifies observations of DRT related flows.  
GBOB General-Head-Boundary Observation  Specifies observations of GHB related flows. GBOB Online Help
CHOB Constant Head Observation  Specifies observations of CHD related flows. CHOB Online Help
RVOB River Observation  Specifies observations of RIV related flows. RVOB Online Help
NWT Newton-Raphson groundwater formulation Solves groundwater-flow equation with Newton-Raphson method; requires UPW or LPF as flow package. NWT Online Help
PCG Preconditioned-Conjugate Gradient Primary MODFLOW-2005 solver. PCG Online Help
PCGN PCG solver with improved nonlinear control Solver with advanced dampening and relaxation for highly nonlinear groundwater models. PCGN Online Help
GMG Geometric MultiGrid Solver  Geometric multigrid preconditioner to conjugate gradient solver. GMG Online Help
DE4 Direct Solution Solver Use Gaussian elimination solver for the groundwater-flow equation. DE4 Online Help
SIP Strongly Implicit Procedure  Legacy code—recommended to use PCG or PCGN. SIP Online Help
KDEP Hydraulic-Conductivity Depth-Dependence Capability HUF extension that allows for the automatic calculation of depth‑dependent horizontal hydraulic conductivity. KDEP Online Help
LVDA Model-Layer Variable-Direction Horizontal Anisotropy  HUF extension that allows for the automatic variable-direction horizontal anisotropy. LVDA Online Help



Superseded Versions

The following software is not actively supported by the USGS. Software listed below have been categorized as:

  • Superseded: software has been replaced by newer software

The software is provided online for historical reference only, and the pages may contain outdated information or broken links.



For more detailed information, please visit MODFLOW One-Water Hydrologic Flow Model—Conjunctive Use Simulation Software (MF-OWHM)