Green Stormwater Infrastructure (GSI)



Keeping our Drinking Water Clean

What is stormwater runoff?

Stormwater is water from rain that flows off solid surfaces, gathering from puddles to ditches, streams, and eventually flowing into our lakes and rivers. Along the way, stormwater picks up pollutants – including automobile fluids, pesticides, fertilizers, sediment, pet waste and litter, to name a few. As a result, excess algae, sediment, and toxic chemicals end up in the the rivers and lakes that supply our drinking water, making the water unfit for consumption. New development increases stormwater runoff by adding more hard surfaces to our communities, which prevent water from soaking into the ground. When these pollutants enter our streams, it’s not only harmful to the ecosystems, but it costs more to treat the water so that it’s safe to drink.

How can we reduce pollution?

To protect existing and future drinking water supplies, municipalities and counties must look at our water systems as more than just drinking water or stormwater, but rather as one integrated system. Municipalities need to look at innovative ways to manage stormwater, create incentives to capture and reuse stormwater, and increase land conservation and stream restoration. While personal actions, like the installation of rain gardens and rainwater capture systems in individual homes, can help solve our water problems, you can have an even greater impact by advocating for policy changes that require Wake County and its municipalities to improve stormwater management.


“Do unto those downstream as you would have those upstream do to you.”

– Wendell Berry


Stormwater Street Sign

What is GSI and how can it help?

Green Stormwater Infrastructure (GSI) is a land use planning and design approach that helps limit environmental degradation from growth and development by letting water filter naturally. It makes use of “permeable” structures, (structures that allow water to pass through them) to filter rain water on-site. This minimizes pollutants washing into our streams by cleaning the water as it soaks into the ground (it then enters our streams via groundwater). North Carolina State University initiated the NC LID Group, a clearinghouse of information on the principles of green stormwater infrastructure to improve understanding, and ultimately implementation, of these projects. The Low Impact Development Guidebook for North Carolina is also a great resource for GSI information.


This type of infrastructure encompasses the concepts and tools that could be key to restoring Wake County’s water systems, and cleaning up Falls Lake and Jordan Lake. Reducing stormwater pollution improves water quality; using stormwater for irrigation and other non-potable purposes extends our limited groundwater supply; increasing infiltration of stormwater enlarges our water supply. With appropriate stormwater management and land development practices, stormwater can be an asset rather than a liability.

Interested in learning more about Green Stormwater Infrastructure? View these presentations or watch the video below from “How to be Water Smart in the Triangle” one of WakeUP’s community forums about water.

One Water in the Triangle: Reconnecting Water to Build Better Communities – Trevor Clements

A One Water Approach to Restoring Durham’s Rivers and Streams – Chris Dreps

Raleigh’s Strategies for Advancing Green Infrastructure and Low Impact Development – Kevin Boyer