Version 6.4.1 of the River Analysis System (HEC-RAS) is now available. This version supersedes previous versions.

A list of major and minor the bugs fixed between versions can be found in the "Problems Repaired" pages.  Fixes for version 6.4 can be found here: Version 6.4. Fixes for 6.4.1 can be found here: Version 6.4.1.


The installation program and all documentation for HEC-RAS are available on the HEC website at .  This new release is installed independently of any previous versions of the software.  Users may have the new version and previous versions of HEC-RAS software installed simultaneously for parallel use or testing.  HEC-RAS Version 6.4 is fully compatible with projects developed in any previous version of the software.

The installation process includes steps of selecting a directory for the HEC-RAS Version 6.4 software files and making other settings (e.g., creating a desktop shortcut, if desired).  Use the following steps to install the program on the Microsoft Windows® operating system:

  1. Download the HEC-RAS installation package from the HEC website to a temporary folder on the computer.
  2. Run the installation program. In Windows Explorer, double-click the icon for the installation program.  Note, you need administrator privileges to run the installer.
  3. Follow the on-screen prompts to install the program.


HEC-RAS Version 6.0 and newer will only run on 64-bit Windows operating systems, including 64-bit versions of Windows 7, 8.0, 8.1, 10 and 11.  Also, make sure your operating system is up to date with all of the Microsoft patches for that version of the operating system before trying to install HEC-RAS.

Support Policy

Technical support for program users within the Corps of Engineers is provided through an annual subscription service.  Subscribing offices can expect full support from HEC staff in the routine application of the program.  Users are strongly urged to consult with HEC staff on the technical feasibility of using the program before beginning a project with unique requirements.  Extended support for large or complex projects can be arranged under a separate reimbursable project agreement.

Reporting of suspected program errors is unrestricted and we will reply to all correspondence concerning such errors.  We are continuously working to improve the program and possible bugs should always be reported.  Reports should include a written description of the steps that lead to the problem and the effects that result from it.  If we cannot reproduce the reported problem, we may ask you to send a copy of your project.

Report program errors through the following channels: