Download and Install HEC-WAT

HEC-WAT has been created using the Java programming language. Software written in the Java language can run on almost any operating system. However, HEC-WAT has several native dependencies that require operating system specific code.  In addition, HEC-WAT is capable of running several other software packages that may not be available for additional operating systems, in particular the HEC-RAS plugin for HEC-WAT only supports MIcrosoft Windows.

Microsoft Windows

We provide a HEC-WAT build for the Microsoft Windows operating system, tested on Windows 10 and Windows 11, although it may work on other versions of Windows.  This testing has been performed on a standard "Science and Engineering" grade laptop and software configuration used by the US Army Corps of Engineers.  Other organization's may have Windows system configurations that are not compatible with HEC-WAT or require changes to the HEC-WAT settings to work correctly.  Please report any system configuration issues through the HEC-WAT bug report process.  We recommend using the latest patches for the Windows operating system used to run HEC-WAT.

Linux

Upon request, we can provide a HEC-WAT build for Linux-based operating systems, but we cannot provide support and have not extensively tested this build.  Several HEC applications that can be used within HEC-WAT have Linux versions and these can be used within HEC-WAT on Linux, but not all applications are available or tested.  We have performed some limited testing on Ubuntu, Debian, and Fedora Linux systems, but users are expected to perform their own validation and use extreme caution with these builds.

Minimum Requirements

The minimum recommended hardware requirements to run HEC-WAT 1.1 in a Windows 11 environment are:

• 64-bit x86 processor with 4 cores (minimum) with additional cores recommended for some applications such as HEC-RAS and HEC-HMS.
• 4 gigabytes of RAM (minimum), recommend additional RAM for most applications.
• 1.9 gigabytes of storage space for the HEC-WAT program,
• Additional storage space for models on the local machine.  The size of a HEC-WAT study ("watershed") and model outputs will vary significantly.  For a smaller model, less than a gigabyte of storage may be sufficient, while large studies may need hundreds of gigabytes of storage.  We strongly recommend against running a HEC-WAT model stored on a network drive as it will create performance issues.
• Display: Screen resolution of at least 1366 x 768 as a minimum, however some elements of the HEC-WAT's user interface may require a 1920 x 1080 ("Full HD") resolution or higher when editing HEC-WAT models.  "High DPI" displays may require software specific settings for some UI elements render correctly.

Requirements for Specific Modeling Applications

While HEC-WAT itself does not require substantial resources, it can be used to run various hydrologic and hydraulic engineering software that may have more substantial requirements.  For an existing model, the hardware requirements to run and use that specific model, as well as the computational time required, are expected to remain similar when used within an HEC-WAT study. For an example tutorial that helps you estimate the computation time for a simulation, please review the FRA Compute Time (HEC-WAT Tutorials and Guides).

Note: The HEC-WAT "Flood Risk Analysis" Nested Monte Carlo feature will run these models thousands of times or more, and so a user should plan to optimize their model for fast computational times when applying this feature.  Without enabling additional features within HEC-WAT, the compute time and storage requirement for these single-event model will scale approximately linearly with the number of events required.

HEC-WAT Distributed Compute

HEC-WAT allows for a distributed compute option that allows sending individual compute jobs out to a network of machines or compute nodes.  In addition to a network connection between machines capable of sustaining a moderate amount of data transfer (such as gigabit-speed ethernet or better), each compute node will need similar resources to those needed to run the HEC-WAT model on a single computer.

Download and Install HEC-WAT

Choose an Installation Directory

Important Directory Considerations:

• Choose a location where you have write permissions (e.g., C:\Programs) to easily modify configuration files or update components.
• Use short, simple folder paths to make navigation and file handling easier.

Download HEC-WAT

To download the HEC-WAT Version 1.1 portable package:

1. From the HEC-WAT Downloads page, download the latest version of the software.  This is a portable setup package as a ".zip" file that includes HEC-WAT and the following HEC modeling applications as plugins: HEC-HMS, HEC-ResSim and HEC-FIA.   HEC-RAS is not included with HEC-WAT and needs to be installed by an administrator to register the correct files with Windows so that HEC-WAT can find it.
2. Extract the contents of the *.zip file to a location from where you can run applications.  We recommend storing the software in a folder on your primary drive, such as C:\Programs\HEC-WAT , and avoid running the software from your desktop or Windows user directory.
   

    USACE users: Do not use Windows' built-in extractor – it may cause issues when trying to run HEC-WAT. Instead, use 7zip to extract the files.

Install and Register HEC-RAS

If you plan to use HEC-RAS complete this step. If not, skip this step and disable the HEC-RAS plugin from the "Plugin Information" option, found under the "Tools" menu of the main HEC-WAT window. (For more information review, the HEC-WAT Plugins section on this page).

HEC-WAT Version 1.1 expects HEC-RAS Version 6.5 to be installed and registered, typically requiring administrator access. HEC-RAS Version 6.5 is not included with the HEC-WAT package and must be downloaded and installed separately. HEC-RAS must be installed using the Setup program, which decompresses and installs the files to the appropriate directories, as well as registers certain shared libraries with the operating system. 

USACE users: Use the App Portal to install HEC-RAS Version 6.5

Alternatively, to manually install HEC-RAS:

1. Go to the HEC-RAS Downloads page and find the Version 6.5 install package.
2. Download the setup program in a temporary directory and execute it from there (double-click on the EXE to start the installer).
3. Follow the setup instructions on the screen and install HEC-RAS in the folder identified in the installer.
   For more information review Installing HEC-RAS (Version 6.5) (HEC-RAS User's Manual).
4. When launching HEC-WAT, the RAS plugin will occasionally fail to load, if this happens, close and restart HEC-WAT.  If this happens repeatedly, you may need to check that the HEC-RAS software is installed correctly, or that the correct version has been installed.

Open HEC-WAT

First Time Using HEC-WAT

After installing the software, to quickly find and open HEC-WAT choose from any of the recommended actions below:

• Create a shortcut on your desktop: navigate to the unzipped folder and in the HEC-WAT directory, right-click the "HEC-WAT.exe" and select Create shortcut (if in Windows 11, select Show more options to see the Create shortcut option). Then drag the created shortcut to the desktop. Double-click to open the HEC-WAT software.
• Pin HEC-WAT to the taskbar: right-click the HEC-WAT.exe (shortcut or original) and select Pin to taskbar (if in Windows 11, select Show more options to see the Pin to taskbar option). Click the pinned HEC-WAT software icon to open the software.
• Pin to Start: right-click on the HEC-WAT.exe (shortcut or original) and select Pin to Start. Open the Start menu and click on the pinned HEC-WAT software.

If you encounter a Microsoft Defender SmartScreen warning, it can be safely ignored. Click More info and Run to continue.

The splash screen for HEC-WAT will open and will appear for a few seconds. Accept the Terms and Conditions for HEC-WAT and the included plugins. And then the main window of HEC-WAT will appear. HEC-WAT is now ready for use. 

Click here to expand to see the interface...

If one of the plugins fails to start, close and reopen HEC-WAT.  The plugin loading process may occasionally fail, and restarting HEC-WAT should clear the issue.  If the plugin repeatedly fails to load, try opening the standalone program to see if it launches successfully outside of HEC-WAT.

If a user does not need a specific plug-in as part of their model, it is recommended to turn it off, as this will decrease the time required to start HEC-WAT and potential errors that can result from that plug-in failing to start correctly.

To disable an HEC-WAT default plug-in: 

1. From the HEC-WAT main window, from the Tools menu, click Plugin Information.
2. The Plugin Information dialog opens to the Plugin Status tab. The table that is displayed provides information on all of the current plug-ins that are available in
   HEC-WAT.
   Click here to expand to see the interface...

   

   
   

3. HEC-FIA will not be used in the RussianRiver study, so for the FiaPluginClient uncheck the checkbox in the Enabled column and click Apply to disable the plug-in.
4. Click OK to close the Plugin Information dialog.
5. Close and reopen the HEC-WAT software.