Urban runoff is the single biggest threat to water quality in San Diego.1
Urban runoff is water that flows over man-made surfaces in densely populated areas and drains directly into our water bodies. Stormwater, irrigation and other water absorb the materials on top of the surfaces including pollutants such as oil, grease, pesticides, metals, bacteria and viruses and toxic chemicals.
And then washes it all into our rivers, bays, lakes and ocean.
In Southern California, storm drains carry millions of gallons of polluted runoff to the ocean everyday. In San Diego, all public storm drains directly link to our beaches without any wastewater treatment.
Urban runoff creates negative impacts such as these:
- The San Diego County Department of Environmental Health advises beach users to avoid contact with ocean and bay waters for 72 hours after it rains.
- During dry weather, the Department of Environmental Health advises us to avoid recreational waters within 75 feet of where runoff enters it.
- Some San Diego beaches have closed for three-month stretches because of contaminated runoff.
- Human illnesses have been clearly linked to recreational use of coastal waters near storm drains.
- Urban runoff pollutants build up in the tissues of fish and other aquatic animals, which people eventually eat.
1 Southern California. 2000. KC Schiff, MJ Allen, EY Zeng, SM Bay. Marine Pollution Bulletin 41:76-93.