This page provides a list of nationally and locally accepted hydraulic models that meet National Flood Insurance Program (NFIP) requirements for flood hazard mapping activities. This page is intended for Engineers, surveyors, floodplain managers and FEMA mapping partners.
Disclaimers
- This website lists models, where the compliance with the requirements of 44 CFR 65.6(a)(6) has been previously demonstrated for use in FEMA flood hazard studies and/or mapping efforts. The lists include models that professional engineers can use to perform engineering analysis and mapping for flood insurance studies, however a model’s inclusion on this list does not indicate whether its approval or certification is current as to any other governmental agency. Professional engineers are ultimately responsible for the appropriate application and accuracy of the results.
- FEMA is not responsible for technical support or accuracy of the results and has not evaluated the technical soundness of the models independently.
- This list cannot be used as a marketing tool explicitly or implicitly anywhere.
- FEMA updates its list as necessary. However, the accuracy of this list is not guaranteed. It is highly recommended that model selection is discussed with FEMA before undertaking or initiating any analysis intended to be submitted to FEMA.
- FEMA provides this list for reference only and, in doing so, does not endorse any non-federal products, companies or services. If you believe that any information provided on this page is inaccurate, please contact FEMA at 1-877-FEMA MAP (1-877-336-2627).
Current Nationally Accepted Hydraulic Models
Hydraulic Models: Determination of Water-Surface Elevation for Riverine Analysis
Please reference the following memorandums on the use of HEC-RAS for NFIP purposes. Note that the memorandums are periodically updated, so be sure to read and apply them each time you reference the chart below.
- Policy for Accepting Numerical Models for Use in the NFIP Policy Memorandum
- New Policy for the Use of HEC-RAS in the NFIP
Program | Developed By | Available From | Comments |
|---|---|---|---|
cHECk-RAS | Federal Emergency Management Agency (FEMA) | Federal Emergency Management Agency | cHECk-RAS is a program designed to verify the validity of an assortment of parameters found in the U.S. Army Corps of Engineers (USACE) HEC-RAS hydraulic modeling program. cHECk-RAS utilizes information generated by HEC-RAS (all versions through the latest version, 4.1.0.) This program can run only on computers with Microsoft Windows XP, Vista, or 7 (32- or 64-bit) operating systems. The current version of cHECk-RAS in use is 2.0.1. |
HEC-RAS 3.1.1 and up | U.S. Army Corps of Engineers (USACE) | Water Resources | For water surface elevation difference due to use of different HEC-RAS versions, refer to FEMA Memorandum HEC-RAS Version Updates (August 17, 2004) |
HEC-2 4.6.2 1 | US Army Corps of Engineers (USACE) | Water Resources | Includes culvert analysis and floodway options. |
WSPRO | US Geological Survey, | Federal Highway Administration (FHWA) web page at: | Floodway option is available in June 1998 version. 1988 version is available on the USGS web page at: |
QUICK-2 1.0 and up | FEMA | Federal Emergency Management Agency | Intended for use in areas studied by approximate methods (Zone A) only. May be used to develop water-surface elevations at one cross section or a series of cross sections. May not be used to develop a floodway. |
HY8 4.1 and up | US Department of Transportation, Federal Highway Administration (FHWA) | Federal Highway Administration (FHWA) web page at: | Computes water-surface elevations for flow through multiple parallel culverts and over the road embankment. |
WSPGW 12.96 | Los Angeles Flood Control District | Joseph E. Bonadiman & Associates, Inc. | Windows version of WSPG. Computes water-surface profiles and pressure gradients for open channels and closed conduits. Can analyze multiple parallel pipes. Road overtopping cannot be computed. Open channels are analyzed using the standard step method but roughness coefficient cannot vary across the channel. Overbank analyses cannot be done. Multiple parallel pipe analysis assumes equal distribution between pipes so pipes must be of similar material, geometry, slope, and inlet configuration. Floodway function is not available. |
RASPLOT 3.0 Beta | FEMA | Federal Emergency Management Agency | RASPLOT is a computer program developed by the Federal Emergency Management Agency (FEMA) which allows the user to create flood profiles through the automatic extraction of data from Hydraulic Engineering Centers River Analysis System (HEC-RAS) hydraulic modeling files. Flood profiles are required for inclusion in the Flood Insurance Study (FIS) reports which usually accompany the Flood Insurance Rate Map (FIRM) for communities participating in FEMA’s National Flood Insurance Program. |
StormCAD v.4 (June 2002) and up | Bentley Systems | Bentley Systems | Perform backwater calculations. Should not be used for systems with more than two steep pipes (e.g. supercritical conditions). Inflow is computed by using the Rational Method; the program is only applicable to watershed, which has the drainage area to each inlet less than 300 acres. |
PondPack v. 8 | Bentley Systems | Bentley Systems | Cannot model ineffective flow areas. HEC-RAS or an equivalent program must be used to model tail water conditions when ineffective flow areas must be considered. |
Culvert Master v. 2.0 | Bentley Systems | Bentley Systems | Compute headwater elevations for circular concrete and RCB culverts for various flow conditions. |
XP-SWMM 8.52 and up | XP Solutions | XP Solutions | XP-SWMM cannot represent more than three Manning’s n values per channel section. Where more than this number of values per section are required, the user must demonstrate that the three n values used accurately depict the composite n value for the entire section at various depths. The floodway procedures are for steady flow purposes only. Refer to procedures for unsteady flow floodway calculation posted on the FEMA website at |
Xpstorm 10.0 | XP Solutions | XP Solutions | Xpstorm has the same stormwater modeling capability as the XP-SWMM program. |
Program | Developed By | Available From | Comments |
|---|---|---|---|
HEC-RAS 3.1.1 | US Army Corps of Engineers (USACE) | Water Resources | Calibration or verification to the actual flood events is highly recommended. Floodway concept formulation unavailable. Version 3.1 cannot create detailed output for multiple profiles in the report file. CHECK-RAS cannot extract data. |
FEQ 9.98 and FEQUTL 5.46 | Delbert D. Franz, | U.S. Geological Survey | The FEQ model is a computer program for the solution of full, dynamic equations of motion for one-dimensional unsteady flow in open channels and control structures. The hydraulic characteristics for the floodplain (including the channel, overbanks, and all control structures affecting the movement of flow) are computed by its companion program FEQUTL and used by the FEQ program. |
ICPR 2.20 (Oct. 2000), 3.02 (Nov. 2002), 3.10 (April 2008) with PercPack Option and 4.0 "Pro" (May 2018) | Streamline Technologies, Inc. | Streamline Technologies, Inc. | The model must be calibrated to observed flow and stage records or high-water marks of actual flood events at both channel and floodplain. Floodway concept formulation unavailable; however, version 3 allows users to specify encroachment stations to cut off the cross section. |
SWMM 5 Version 5.0.005 (May 2005) and up | U.S. Environmental Protection Agency (EPA) | Water Supply and Water Resources Division | SWMM 5 provides an integrated environment for editing study area input data, running hydrologic simulations, and viewing the results in a variety of formats. |
UNET 4.0 | U.S. Army Corps of Engineers (USACE) | Water Resources | The model must be calibrated to observed flow and stage records or high-water marks of actual flood events at both channel and floodplain. Comparison of bridge and culvert modeling to other numerical models reveals significant differences in results; these differences may be investigated in the near future. Floodway option is not accepted for NFIP usage. |
FLDWAV | National Weather Service (NWS) | Hydrologic Research Laboratory | Includes all the features of DAMBRK and DWOPER plus additional capabilities. It is a computer program for the solution of the fully dynamic equations of motion for one-dimensional flow in open channels and control structures. Floodway concept formulation is unavailable. |
MIKE 11 HD v.2009 SP4 | DHI Water and Environment | DHI, Inc. | Hydrodynamic model for the solution of the fully dynamic equations of motion for one- dimensional flow in open channels and control structures. The floodplain can be modeled separately from the main channel. |
FLO-2D v. 2007.06 and 2009.06 | Jimmy S. O'Brien | FLO-2D Software, Inc. | Hydrodynamic model for the solution of the fully dynamic equations of motion for one-dimensional flow in open channels and two-dimensional flow in the floodplain. Bridge or culvert computations must be accomplished external to FLO-2D using methodologies or models accepted for NFIP usage. Please review 'Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping (Feb 2002)' thoroughly before applying to alluvial fans. Coordination with the Regional office is required. Calibration to actual flood events is required. Public Domain: No |
XP-SWMM 8.52 and up | XP Solutions | XP Solutions | XP-SWMM cannot represent more than three Manning’s n values per channel section. Where more than this number of values per section are required, the user must demonstrate that the three n values used accurately depict the composite n value for the entire section at various depths. Calibration to actual flood events required. The floodway procedures are for steady flow purposes only. Use the procedure for unsteady flow floodway calculation posted on FEMA website at Floodway Analysis for SWMM Models Public Domain: No |
Xpstorm 10.0 (May 2006) | XP Solutions | XP Solutions | Xpstorm has the same stormwater modeling capability as the XP-SWMM program. |
Program | Developed By | Available From | Comments |
|---|---|---|---|
Adaptive Hydraulics (AdH) version 4.2 and up (June 2012) | U.S. Army Corps of Engineers (USACE) | U.S. Army Engineer Research and Development Center Coastal and Hydraulics Laboratory 3909 Halls Ferry Rd., Vicksburg, MS 39180 | AdH is a spatially implicit, physics based hydrodynamic model that can simulate a wide range of hydraulic features, including rainfall and evaporation, overland flooding, wind and wave effects, friction impacts due to vegetation, and·several types of hydraulic structures. AdH also includes the ability to simulate time and space varying head and flow boundary conditions, making it suitable in many coastal, estuarine, and riverine applications. AdH has been applied in the high tidal ranges of Alaska and in the deserts of Afghanistan. AdH has been used widely throughout the U.S. for sediment and constituent transport, dam break, tidal impacts, and flooding analyses. User manual and various training resources for the AdH model is available on the AdH website. More information on AdH can be found on the USACE website. Publically Available: Yes |
FESWMS 2DH | U.S. Geological Survey | U.S. Geological Survey | This model has the capability to model sediment transport. |
FLO-2D v. 2007.06 and 2009.06 | Jimmy S. O'Brien | FLO-2D Software, Inc. | Hydrodynamic model that has the capabilities of modeling unconfined flows, complex channels, sediment transport, and mud and debris flows.
|
MIKE Flood HD v.2009 SP4 | DHI Water and Environment | DHI, Inc. | A dynamic coupling of MIKE 11 (one-dimensional) and MIKE 21 (two-dimensional) models. Solves the fully dynamic equations of motion for one- and two-dimensional flow in open channels, riverine flood plains, alluvial fans and in costal zones. This allows for embedding of sub-grid features as 1-D links within a 2-D modeling domain. Examples of sub-grid features could include small channels, culverts, weirs, gates, bridges and other control structures. Please review 'Guidelines and Specifications for Flood Hazard Mapping Partners Appendix C: Guidance for Riverine Flooding Analyses and Mapping (Feb 2002)' thoroughly before applying to floodway analysis. Coordination with the Regional office is required. |
TABS RMA2 v. 4.3 and up | US Army Corps of Engineers (USACE) | Coastal Engineering Research Center | Limitations on split flows. Floodway concept formulation unavailable. More review anticipated for treatment of structures. Please review 'Guidelines and Specifications for Flood Hazard Mapping Partners Appendix C: Guidance for Riverine Flooding Analyses and Mapping (Feb 2002)' thoroughly before applying to floodway analysis. Coordination with the Regional office is required. |
XPSWMM 2D/ | XP Solutions | XP Solutions | The program simulates two-dimensional free surface flows by solving the full-dimensional, depth averaged, momentum and continuity equations. The two dimensional simulation is dynamically linked with the one-dimensional modeling of XP-SWMM/XP-Storm by taking the one-dimensional water surface elevation profile as the internal boundary condition of the 2D domain. Flow rates transferred depend upon the head difference and the roughness of cells. Please review 'Guidelines and Specifications for Flood Hazard Mapping Partners Appendix C: Guidance for Riverine Flooding Analyses and Mapping (Feb 2002)' thoroughly before applying to floodway analysis. Coordination with the Regional office is required. |
| HEC-RAS Version 5.0 | U.S. Army Corps of Engineers (USACE) | Water Resources Support Center Corps of Engineers Hydrologic Engineering Center 609 Second Street Davis, CA 95616-4687 | HEC-RAS Version 5.0 has the ability to perform two-dimensional (2D) hydrodynamic routing within the unsteady flow analysis portion of HEC-RAS. Users can now perform one-dimensional (1D) unsteady-flow modeling, two-dimensional (2D) unsteady-flow modeling (Saint Venant equations or Diffusion Wave equations), as well as combined 1D and 2D unsteady-flow routing. The 2D flow areas in HEC-RAS can be used in number of ways. Version 5.0 of the River Analysis System (HEC-RAS) is now available. This Version supersedes Version 4.1, and all previous versions. Several new simulation features have been added to the software since that time. Version 5.0 of HEC-RAS includes the following new features:
1. Two-dimensional and combined one- and two-dimensional Unsteady Flow Modeling 2. New HEC-RAS Mapper capabilities and enhancements 3. Automated Manning’s n value calibration for one-dimensional Unsteady Flow 4. Simplified Physical Breaching algorithm for Dam and Levees 5. Breach Width and development time calculator 6. New Hydraulic outlet features for Inline Structures 7. Sediment Transport Modeling Enhancements: Including Reservoir flushing and sluicing, as well as channel stability using BSTEM integrated within HEC-RAS 8. Water Quality Modeling Enhancements 9. Completely new two-dimensional User’s Manual 10. Several new example applications within the Applications Guide 11. Updates to User's Manual, Hydraulic Reference Manual, Applications Guide, and Help System The installation program and all documentation are available on the HEC website. This new release is installed independently of any previous versions of the program. Users may have the new version and previous versions of HEC-RAS software installed simultaneously for parallel use or testing. This new version is fully compatible with projects developed in any previous version of the program. However, once a project has been opened in Version 5.0 and saved, it may not be possible to open it with an older version of the software and reproduce the old results. Public Domain: Yes |
Sedimentation and River Hydraulics, Two-Dimensional River Flow Model (SRH-2D) | U.S. Bureau of Reclamation Technical Service Center Sedimentation and River Hydraulics Group Denver Federal Center 6th and Kipling, Building 67 Denver, Colorado 80225-0007 | 1200 New Jersey Avenue, SE Washington, DC 20590 | SRH-2D, Sedimentation and River Hydraulics – Two-Dimensional model, is a two-dimensional (2D) hydraulic, sediment, temperature, and vegetation model for river systems. The SRH-2D model can be executed independently of any third party software, but pre-processing greatly facilitates development of the computational mesh elements. Public domain alternatives are available for this pre-processing. However, FHWA has contracted with the firm AquaVeo to integrate the SRH-2D model into their Surface-water Modeling System (SMS). SRH-2D may be applied but not limited to: Flow in one or multiple streams covering the main channel, side channels, and floodplains; Hybrid mesh methodology which uses arbitrary mesh cell shapes; Flood routing and inundation mapping over any terrain; Flow around in-stream structures such as weirs, diversion dams, release gates, coffer dams, etc.; Flow over-spill over banks and levees; Flow over vegetated areas and interaction with main channel flows; Flow in reservoirs with known flow release; and Morphological assessment of bed erosion potential. Public Domain: Yes |
1 The enhancement of the program in editing and graphical presentation can be obtained from several private companies.
Current Locally Accepted Hydraulic Models
Hydraulic Models: Determination of Water-surface Elevations for Riverine Analysis
| PROGRAM | DEVELOPED BY | AVAILABLE FROM | COMMENTS |
|---|---|---|---|
| One-Dimensional Unsteady Flow Models | |||
| NETWORK (Jun. 2002) | Southwest Florida Water Management District | Engineering Section Resource Management Department 2329 Broad Street Brooksville, Florida 34604-6899 | Interconnected ponds and channels routing model. Only accepted for usage within Southwest Florida Water Management District. Public Domain: Yes |
| CHAN for Windows v.2.03 (1997) | Aquarian Software, Inc. | Aquarian Software 1415 Briercliff Drive Orlando, Florida 34604-6899 | Calibration or verification to the actual flood events is highly recommended. Floodway concept formulation is unavailable. Encroachment stations can be specified in editor to cut off section. Only accepted for usage within Southwest Florida Water Management District. Public Domain: No |
| MIKE URBAN Collection Systems (MOUSE) Release 2009, dated June 2010 | DHI Water and Environment | DHI, Inc., 319 SW Washington St., Suite 614, Portland, OR 97204 | MIKE URBAN has the capability to analyze storm sewer networks. Flow conditions associated with weirs, orifices, manholes, detention basins, pumps, and flow regulators can be reflected. Weirs located within the closed conduit have to be modeled as orifices. MOUSE does not independently have the capability to model overland flows; overland flow can be analyzed by coupling MIKE 11 and/ or MIKE 21. Floodway modeling capability is not available. The compliance of the hydrology module of MOUSE is not determined. Calibration to actual flood events is required. Only Accepted for usage within areas administered by FEMA Region III (DC, DE, MD, PA, VA and WV) Public Domain: No |
| FLO-2D Pro | Jimmy S. O'Brien | FLO-2D Software, Inc. P.O. Box 66 Nutrioso, AZ 85932 | An integrated river and floodplain model. A flood routing hydrologic and hydraulic model with urban detail features, sediment transport, mudflow, and groundwater modeling Please review 'Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping (Feb 2002)' thoroughly before applying to alluvial fans. Coordination with the Regional Office is required. Calibration to actual flood events is required. Only accepted for usage within Mohave County, Pima County, Pinal County, and Maricopa County, Arizona. Public Domain: No |
| Interconnected Channel and Pond Routing, Version 4 (ICPR4), Integrated 1-D/2-D Surface Hydraulics and 2-D Groundwater Model | Streamline Technologies, Inc. | 1900 Town Plaza Ct. Winter Springs, FL 32708 | Hydrology, integrated 1-D/2-D surface hydraulics and 2-D groundwater model.
Only accepted for usage within the State of Florida, County of Georgetown, SC, City of Lubbock, TX, and the City of Lafayette, IN.
Public Domain: No |
| Two-Dimensional Unsteady Flow Models | |||
| S2DMM (Feb. 2008) | Tomasello Consulting Engineers, Inc. | Tomasello Consulting Engineers, Inc. 5906 Center Street Jupiter, FL 33458 | Applicable to a network of rectangular grids. Capable of routings on natural overland sheetflow areas and water management systems with cascading lakes and channels. Computing runoff from either daily or hourly rainfall with design distributions, using SCS formula with soil storage and soil moisture updated on daily basis. Stage/storage, sheetflow cross sections, and soil types are represented in each computational grid entered via GIS. HEC-2 type cross sections can be entered on specific channel grids and minor channels can be embedded on general grids. Evapotranspiration computations are based on seasonal factors and soil moisture of unsaturated and saturated zones. Interactions with the subsurface conditions are handled by MODFLOW routines. Capable of simulating continuous hydrologic conditions. Cannot compute regulatory floodway. Please review Appendix C of the Guidelines and Specifications for Flood Hazard Mapping Partners, “Guidelines for Riverine Flooding Analyses and Mapping” thoroughly before applying to floodway analysis. Coordination with the Regional office is required. The model must be calibrated to observed flow and stage records or high-water marks of actual flood events at both channel and floodplain. Only accepted for usage in the South Florida Water Management District. Public Domain: No |
| TUFLOW Release Version 2016-03, and up | BMT WBM | BMT WBM www.bmtwbm.com Suite 120 8200 S. Akron Street Centennial Denver, CO 80112 United States Software info: www.tuflow.com Aquaveo www.aquaveo.com 3210 N. Canyon Road Suite 300 Provo, Utah 84604 United States | TUFLOW is flood simulation software that simulates the hydrodynamics of water flow using the complete 2D and 1D free-surface flow equations. It includes a wide range of options for modeling structures and urban pipe networks, and for dynamic linking of 2D and 1D solutions. The program is applicable to riverine flooding, dambreak inundation, urban overland and pipe network flows, and coastal inundation from surges and tsunamis. The model must be calibrated to observed flow and stage records or high-water marks of actual flood events at both channel and floodplain. Currently floodway concept formulation is not available. Please review Appendix C of the Guidelines and Specifications for Flood Hazard Mapping Partners, “Guidelines for Riverine Flooding Analyses and Mapping” thoroughly before applying to floodway analysis. Coordination with the Regional office is required. Only accepted for usage in FEMA Region III, and in the City of Simi Valley, California. Public Domain: No |
| Two-Dimensional Steady/Unsteady Flow Models | |||
| DHM 21 and 34 (Aug. 1987) | Theodore V. Hromadka II and Chung-Cheng Yen | Hromadka & Associate Costa Mesa, California | Diffusion flow model that can route unconfined surface and open channel flows. Can be used to model alluvial flooding. Rainfall-runoff output can be used for hydrologic studies. Kinematic routing optional. Floodway concept formulation unavailable. Calibration to actual flood events is recommended. |
| FLO-2D Pro | Jimmy S. O'Brien | FLO-2D Software, Inc. P.O. Box 66 Nutrioso, AZ 85932 | An integrated river and floodplain model. A flood routing hydrologic and hydraulic model with urban detail features, sediment transport, mudflow, and groundwater modeling Please review 'Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping (Feb 2002)' thoroughly before applying to alluvial fans. Coordination with the Regional Office is required. Calibration to actual flood events is required. Only accepted for usage within Mohave County, Pima County, Pinal County, and Maricopa County, Arizona. Public Domain: No |
| Interconnected Channel and Pond Routing, Version 4 (ICPR4), Integrated 1-D/2-D Surface Hydraulics and 2-D Groundwater Model | Streamline Technologies, Inc. | 1900 Town Plaza Ct. Winter Springs, FL 32708 | Hydrology, integrated 1-D/2-D surface hydraulics and 2-D groundwater model.
Only accepted for usage within the State of Florida, County of Georgetown, SC, City of Lubbock, TX, and the City of Lafayette, IN.
Public Domain: No |
| InfoWorks ICM (Integrated Catchment Modeling) v. 8-series | Innovyze | 6720 SW Macadam Ave., Suite 150 | Hydrology and integrated 1-D/2-D surface hydraulics. Only accepted for usage within Santa Clara County, California. Public Domain: |
| TUFLOW Software Suite | BMT Group Ltd | BMT Group Ltd Level 8 200 Creek Street Brisbane 4000 Australia | 1D network and 2D fixed grid based software for simulating flood and tidal flow. Only accepted for usage within Ventura County, California. Public Domain: No |
View More Nationally and Locally Accepted Models
Below are additional nationally and locally accepted models in the NFIP Program:
- Coastal Models Meeting the Minimum Requirement of NFIP
- Hydrologic Models Meeting the Minimum Requirement of NFIP
- Statistical Models Meeting the Minimum Requirement of NFIP
Numerical Models No Longer Accepted
Please visit the Numerical Models No Longer Accepted by FEMA for NFIP Usage page for a list of unaccepted models.