As I couldn't find a direct link to download the software, I recommend visiting the official Bentley website or contacting their support team for more information on obtaining the software.
Bentley StormCAD is a comprehensive stormwater management software that enables engineers, planners, and designers to analyze, design, and optimize stormwater drainage systems. It's widely used for planning, designing, and managing stormwater infrastructure. bentley stormcad v8i ss5 081105113epub link
Here's a brief report on the software: