Green infrastructure is an approach that communities can use to maintain healthy waters. Green infrastructure addresses several different water issues including stormwater management, flooding mitigation, and improving water quality and supply. Unlike traditional stormwater systems that use pipes to transport rainwater and divert pollutants into nearby bodies of water, green infrastructure uses vegetation and soil to manage rainwater where it falls, therefore reducing stormwater volume discharge. The vegetation used in green infrastructure naturally filters and breaks down many of the common pollutants found in stormwater runoff. Along with reducing pollutants, green infrastructure can reduce the frequency of sewer overflow events by reducing runoff volumes and by delaying stormwater discharges.
In addition to stormwater management, green infrastructure enhances groundwater recharge. Green infrastructure techniques can improve the rate at which groundwater aquifers are replenished by replacing impervious surfaces with pervious surfaces, thus improving water infiltration. This is important as around 40 percent of water needed to maintain normal levels in rivers and streams comes from groundwater. More recharged groundwater can also boost the supply of drinking water.
Finally, green infrastructure can be used as a systematic approach to conserving and enhancing wetlands and floodplains that provide many important environmental benefits including improved water quality, groundwater recharge, shoreline anchoring, flood control and a habitat for wildlife.