Windows automatically blocks macros in files downloaded from the internet to protect against malware.

Always perform a sanity check on the output. Does the final design head seem reasonable given the discharge and spillway length? Does the downstream profile match a smoothly curving ogee shape? If something looks odd, investigate—the spreadsheet may have a hidden error.

Ensuring the profile prevents sub-atmospheric pressure (cavitation).

Before discussing the installation, let’s define the software.

The process is straightforward once you understand that it’s a macro-enabled Excel workbook, not a traditional program. By properly unblocking the file, enabling the Solver add-in, and configuring your VBA references, you can go from download to designing a WES-standard spillway profile in under 15 minutes.

This occurs when text characters are typed into numerical input fields, or if there is a conflict between unit systems (mixing meters and feet). Check that your inputs match the designated units of the sheet.

Plug in your design head and crest height to see the magic happen.

Once your installation works, protect it: