Improved Water Quality

As natural, vegetated buffers, greenways that are adjacent to streams and rivers act as filters. These "natural filters" remove many of the pollutants that are found in stormwater, including pesticides, oil, gas, and sediment. This polluted stormwater is not absorbed by rooftops, parking lots or other impervious surfaces. The quality of drinking water supplies and other lakes, rivers and streams can be improved through preserving natural streamside buffers as greenways.

--The natural land along the Alchovy River in Georgia provide valuable water quality functions such as sediment, toxicant and excess nutrient removal. The least-cost substitute for the water quality benefits provided would be a water treatment plant.

--New York City was told by the EPA to construct a $8 billion water filtration facility in order to improve the quality of drinking water supplies. Instead, officials decided to protect 80,000 acres of natural land (including greenways) in their water-supply watershed and achieve the same water quality result for $1.5 billion.