Our landscapes are being permanently altered by the continuous creep of parking lots, rooftops, roadways and other hard surfaces that are impervious to water. When these impervious surfaces reach critical mass, the water cycle is fundamentally altered and polluted stormwater runoff severely degrades our waterbodies. Supplementing our towns’ existing infrastructure with a new kind of “green infrastructure” can help reduce pollution and flooding and improve the condition of our groundwater aquifers.
When it rains in watersheds with large amounts of impervious cover, less water infiltrates into the ground and is transferred to the atmosphere through evapotranspiration, while more water runs off the land’s surface.
Stormwater running off impervious surfaces picks up a host of pollutants, including pesticides and fertilizers we spread on our lawns, petroleum and antifreeze that spill from our cars, leaks from failing septic systems and broken sewer pipes, waste from our pets, soap from washing our cars, road salt we spread on our driveways and sidewalks, to name just a few.
When it rains, this witches brew of pollutants wash over our lawns, driveways, parking lots and streets as “polluted stormwater runoff.” In most cases, the polluted runoff flows into storm drains, then through a series of subterranean pipes that carry the runoff directly to local streams. For most of us, these polluted streams are a source of our drinking water.
Green Infrastructure is an approach to managing stormwater that uses plants, soil, gravel, and certain engineered materials to filter, cleanse, absorb, store, and delay the release of runoff after a rain event. Examples include rain gardens, vegetated swales, green roofs, cisterns, porous pavement, and rain barrels.
We’ve deployed several Green Infrastructure strategies at the Watershed Center. Runoff from portions of the roof is directed to rain gardens that capture and filter the water and allow it to percolate into the ground. A green roof on another wing of the building, slows down and removes water through evaporation and transpiration of plants. We capture runoff from yet another portion of roof into a large cistern and use it to flush toilets.
We are eager to work with municipal governments, businesses, schools, civic centers, and others to help replicate what we’ve done at the Watershed Center in other locations around our region.
With funding support from the New Jersey Department of Environmental Protection, the Watershed is working in 16 central New Jersey towns to deploy Green Infrastructure to address the triple threat of water pollution, flooding, and reduced groundwater recharge. We’re collaborating with Rutgers University, which is working in other towns in the state under a similar grant.