Wash Water (Gray Water)

Stormwater Related Information for Grey Water Systems

Preventing graywater from entering our streets and storm drains helps protect our waterways from pollution!  All sources of pollution, including runoff from graywater, are prohibited from leaving your property; only rainwater is allowed in the streets and storm drains.

Did you know…

  • Graywater is water that was used for various tasks, such as washing machines or showers. Graywater can contain chemicals, bacteria, viruses, detergents or soaps.

  • Graywater is untreated wastewater that can be used for watering landscapes through a designed system of mulch basins or subsurface drip irrigation. 

  • Graywater should be closely managed to avoid runoff into our storm drains since it can degrade our water quality and harm aquatic life.


What can I do?


  • Use Best Management Practices (BMPs): BMPs are techniques or controls used to prevent or reduce the discharge of pollutants, such as graywater, into the storm drain system. Some BMPs for graywater might include using non-toxic, biodegradable products or ensuring that your graywater tank and outlet are well away from stormwater drains. 


Want to learn more?

The resources below provide suggested BMPs and further information on how to protect our waterways. Click the button to view available languages:

WPO Handbook


Know before you go….

Don’t store it: graywater must be appropriately diverted into the landscape or sewer immediately.


Contact Us

If you would like to report a graywater concern, have questions about our program, or would like additional information call the County Storm Drain Pollution hotline at: 1(888) 846-0800 or e-mail us at watersheds@sdcounty.ca.gov 


Thank you for doing your part to protect our waterways!