Parking Lots and Material Storage Management

Stormwater Related Information for Parking Lots and Material Storage Management

Preventing runoff from parking and storage facilities from entering our streets and storm drains helps protect our waterways from pollution!   All sources of pollution, including runoff from parking and storage facilities, are prohibited from leaving your property and entering streets or storm drains. Only rainwater is allowed in the streets and storm drains.

Did you know…

  • Parking lots and storage facilities generate pollutants such as heavy metals, trash, fuel, grease and paint. These pollutants can often enter the storm drain system as a result of a rain event. 

  • Metals such as chromium, cadmium, lead, and zinc have the potential to contaminate drinking water supplies. These metals can also accumulate in aquatic life, where it can not only harm the aquatic life but also those who consume them.

  • Releasing pollutants directly or indirectly into the storm drain system is a violation of the County’s Watershed Protection Ordinance (WPO)


What can I do?

  • Dispose of waste thoughtfully: routine inspections of your site will help ensure the collection of trash, which can then be disposed of in the appropriate receptacles. 
  • Use Best Management Practices (BMPs) for your business: BMPs are techniques or controls to prevent or reduce the discharge of pollutants, such as grease and debris, into the storm drain systems.  BMPs for a parking lot or storage facility could include keeping a regular maintenance and cleaning schedule, securing dumpster lids, keeping stored materials off the ground and covered and ensuring hazardous materials have weatherproof secondary containment.  


Want to learn more?

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

General Pollution
Inspect Your Business
Materials Management Spill Response
Train Your Employees
Loading and Dumpster Areas


Know before you go…

Any automotive spills and/or drips should be cleaned up with dry clean-up methods such as a rag.


Contact Us

If you would like to report a discharge concern regarding a parking lot or storage facility, 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 


Thank you for doing your part to protect our waterways!