Quantifying and Modeling the Impacts of a Network of Rain Gardens on Storm Water Flows and Water Quality

Quantifying and Modeling the Impacts of a Network of Rain Gardens on Storm Water Flows and Water Quality (Dr. Martin)

The objectives of this study are to compare the performance of a rain garden network to a control watershed to quantify reductions in storm water discharge and improvements in water quality, and to develop a simulation model to quantify enhanced benefits of hydrologically-linked rain gardens and to serve as a design tool for future applications. This study will talk place in Westerville, OH and is a collaborative effort between CORGI and OSU.

Following positive results from initial studies, they have been recommended as best management practices by several municipalities. However, there are many unknowns that prevent widespread adoption of this immature technology. An important unknown is how a network of rain gardens will function and best be designed to maximize impacts on the quantity and quality of storm water discharge.

This will be the first study to quantify the impacts and develop a model of a network of rain gardens that includes both residential (downspout) and street side rain gardens. Preliminary results indicate that the gardens reduce storm water runoff from 28% for larger storms to 100% for smaller storms.

Without knowledge about how a network of rain gardens can perform and guidelines for their engineering design and placement, it is not possible for municipalities to realize the full benefits of this low impact development technology.