There was a download of CulvertMaster 10.3.0.3 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The program lies within Education Tools, more precisely Science Tools. This software is an intellectual property of Bentley Systems, Incorporated. The following version: 1.0 is the most frequently downloaded one by the program users. Cvm.exe is the default file name to indicate the CulvertMaster installer.
From the developer:
CulvertMaster allows you to effectively analyze existing culverts and design new ones, from simple barrel crossings to complex embankment cross-drain systems, with different shapes and sizes, special tailwater considerations, and roadway overtopping considering watershed data, culvert characteristics, and even weir geometry.
You may want to check out more software, such as Bentley CulvertMaster, which might be related to CulvertMaster.