Pre-development Imperviousness greater than 50% AND in Colorado

It is very difficult in Colorado. We have two examples, one in Colorado and one in Wyoming. The one in Colorado was a project with a low run-off coefficient after development and the reduction in volume was used to maintain a treatment wetlands that was developed as part of the project for water quality. The wetlands needs a constant source of water to maintain viability. This was an opportunistic situation and is not very land efficient. This project is the Gardens at Spring Creek in Fort Collins. This was not a previously developed site and a portion of the project is in flood plain, but the reduction in volume is achieved, even though we did not have to document it for LEED points. The project in Wyoming collected all the stormwater for the LEED boundary area and routed it to the center of the project where there is a aesthetic lake that needs water to overcome evaporation and seepage, This is the Cheyenne Children's Garden. This was documented for LEED and was a previously developed site.

Deborah, I think this is a great question, and for some discussion on it, see the thread below started by Lucy Williams.