Research in Action

Designing Urban Detention Ponds to Support Healthy Ecosystems

Issue
Stormwater runoff not only overwhelms city sewers, it also damages streams and rivers through erosion and transport of chemical pollution. Handling stormwater near its source by anticipating where and how much water flows across parking lots, rooftops and other impervious surfaces can save millions of dollars that otherwise would have to be directed at controlling flooding and erosion in urban areas.

Stormwater runoff is affected by the amount and intensity of rainfall, as well as by hardened, compacted and covered land surfaces that prevent water from moving into and through soils.

Stormwater management solutions such as vegetated buffer strips, shallow troughs to carry water during rainstorms or snow melts (swales) and detention basins are all examples of green infrastructure. There is no single solution for all situations. Green or ecologically-based designs cost less than traditional sewage solutions, and have the added benefit of controlling problems at the source instead of diverting stormwater to treatment facilities or, worse, leaving it untreated in waterways.

In devising appropriate solutions, the challenge is how to make the designs mimic nature – in other words, how can we create a living sustainable system instead of an engineered control structure?

Action
EPA has invested in just such an approach at its facility in Athens, Georgia, by creating a detention pond “downstream” of several acres of paved parking and roofed buildings. Being a research organization, our goal is to develop a better understanding of the system’s dynamics by monitoring the flow and retention of water (pond hydrology) that sustains aquatic and vegetative life; the types of plants and animals that colonize in or near the pond; and water quality such as pH, solids content and water chemistry.

Results and Impact
Through sharing information about their research, EPA scientists hope to help other communities in their efforts to implement green infrastructure. The Pond Ecosystem is part hands-on learning and part community demonstration project. EPA scientists encourage anyone interested in constructing and maintaining a pond ecosystem to contact them for more information. Creative, cost-effective solutions are encouraged, so if you have a success story of your own, please let us know. Spreading the word is the key to making a difference.

Technical Team: Craig Barber