What do you want the calculations to say?
"Have you ever felt that justifying your detention design to a reviewing agency was a game of numbers? Do you have ways of making that marginal design look like a winner? Most engineers do," wrote Glenn E. Brooks in the September 2007 issue of Stormwater magazine. He is the County Engineer with Albermarle County, Virginia.
"After all, hydrology is a science of guessing the future, and it has been shown time and again that the accuracy of these guesses can be very poor. Then, there is often doubt whether small site facilities actually provide a net benefit over a large regional watershed. These points, and others, provide more than enough leeway to be flexible with the numbers."
"More than ever, it should be evident that having a result in mind can be a significant bias in any calculation. The savvy engineer is not always facetious when asking, 'What do you want the calculation to say?' And the answer depends largely on whose side you represent: the developer’s, the regulator’s, the future owner’s, or the downstream neighbor’s," concludes Glenn E. Brooks.
TO LEARN MORE: To read the complete story as published in Stormwater magazine, click on Stormwater Detention: Ten proven ways to cheat. Glenn E. Brooks has a website that provides software for civil engineering. They are offered as freeware. To access his site, click here.
Acknowledgement: Before STORMWATER, The Journal for Surface Water Quality Professionals, there was no single publication written specifically for the professional involved with surface water quality issues, protection, projects, and programs.