Save water and reduce runoff. Install permeable pavement.
Stormwater runoff is a major cause of beach and water pollution (see NRDC's annual rating of water quality at 200 popular beaches in the report Testing the Waters). One way to reduce stormwater runoff is to replace impermeable surfaces such as driveways and sidewalks with permeable pavement. The Biological and Agricultural Engineering Department at the North Carolina State University provides descriptions of types of paving and research on their effectiveness.
For other ways to reduce stormwater runoff, click here and here. Also, check out this NRDC slide show with examples of communities across America cleaning up their water—and saving money—with low-impact development. For more, see what these Smarter Cities are doing to protect water quality: Burnsville, Minnesota; Norwalk, Connecticut; Kansas, City, Missouri; Ann Arbor, Michigan; Santa Monica, California; and Denver, Colorado.