UG_210_21_8 - UG 210-21-8 ENG – HEC-EFM, Version 5.0, Computer Program and Documentation
UG 210-21-8 ENG – HEC-EFM, Version 5.0, Computer Program and Documentation
User Guide: 210-21-8 Date: May 28, 2021
Subject: ENG – HEC-EFM, Version 5.0, Computer Program and Documentation

Purpose.   This user guide announces the availability of the U.S. Army Corps of Engineers (USACE) Hydrologic Engineering Center – Ecosystem Functions Model (HEC-EFM), version 5.0, computer program and explains how to obtain the software and program documentation.
Effective Date.   Effective upon receipt.

Background.   HEC-EFM is an analysis tool developed by the USACE-HEC designed to help study teams determine ecosystem responses to changes in the flow regime of a river or connected wetland. HEC-EFM analyses involve statistical analyses of relationships between hydrology and ecology; hydraulic modeling; and use of geographic information systems to display results and other relevant spatial data. This enables study teams to visualize and define existing ecological conditions, highlight promising restoration sites, and assess and rank alternatives according to predicted changes in different aspects of the ecosystem. Users can apply HEC-EFM quickly and incorporate expert knowledge. HEC-EFM is applicable to a wide range of riverine and wetland ecosystems.

HEC-EFM analyses support planning, implementation, and monitoring for flood damage reduction and environmental restoration measures; can be used to document wetland hydrology; are useful for wetland determinations and wetland restoration planning and design; are useful for planning and design of aquatic organism passage projects; and support determination of appropriate planting zones for vegetation that is sensitive to differences in the frequency, duration, and timing of inundation.

Special Instructions.  HEC developed HEC-EFM for USACE use, but distributes the software to the public for use without restriction. The user assumes all responsibility for determining the suitability of HEC-EFM for specific applications and the accuracy of results. HEC provides limited assistance for this software to non-USACE users through a public discourse website. For full information, see the USACE Software Support Policy website at

This issuance does not include the HEC-GeoEFM or HEC-EFM Plotter software developed by HEC that operates in conjunction with HEC-EFM, version 5.0.

The technical contacts, listed below, are evaluating this software for wider use as part of NRCS’s conservation mission. If you successfully apply the software to NRCS programs, please inform the technical contacts of your experience to aid them in this evaluation.

Distribution.   NRCS tested and CCE (common computing environment) certified HEC-EFM, version 5.0, for deployment to NRCS Information Technology Service (ITS) supported workstations on May 18, 2021. The project reference number is CRQ#3971810.

NRCS users are to obtain HEC-EFM, version 5.0. through their ITS managers. HEC-EFM program documentation is available through the HEC-EFM Documentation website at

This user guide updates and replaces User Guide 210-20-8: ENG – HEC-EFM 4.0 Computer Program and Documentation, dated September 29, 2020.

Filing Instructions.  Users wishing to retain paper copies of any HEC-EFM documentation should place it in a three-ring binder adjacent to other technical directives.

Contact.   NRCS does not have an established internal support framework specifically for HEC-EFM; however, users may direct general questions to: 

  • Maria Hrebik, Wetland Hydraulic Engineer at the Central National Technology Support Center at or (817) 509-3296, or

  • Jon Fripp, Stream Mechanics Engineer at the National Design, Construction, and Soil Mechanics Center at or (817) 509-3771.

Contact Claudia C. Hoeft, National Hydraulic Engineer, Conservation Engineering Division, at or (202) 720-0772 with questions regarding this directive.



Deputy Chief for Science and Technology 
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