Soil, cement wash, asphalt, oil and other hazardous debris from construction sites can make their way into the San Mateo County storm drain system, flowing untreated into local creeks, the San Francisco Bay, and the Pacific Ocean. This page provides resources to help project applicants include construction stormwater controls in development project designs. These resources are organized in the following sections:


Construction BMP Tips

Follow these best management practices to prevent pollution, protect public health and avoid fines or legal action:


Store Materials Safely: Keep construction materials and debris away from the street, gutter and storm drains. Cover exposed stockpiles of soil, sand or gravel and excavated material with plastic sheeting, protected from rain, wind and runoff.


Preventing Erosion: Riparian Erosion and Sediment Control brochure. Avoid excavation or grading during wet weather. Plant temporary vegetation or add hydro mulch on slopes where construction is not immediately planned and permanent vegetation once excavation and grading are complete. Construct diversion dikes to channel runoff to a detention basin and around the construction site. Use gravel approaches where truck traffic is frequent to reduce soil compaction and limit the tracking of sediment into the streets.


Cleaning & Preventing Spills: Use a drip pan and funnel when draining or pouring fluids. Sweep up dry spills, instead of hosing. Be ready for spills by preparing and using spill containment and cleanup kits that include safety equipment and dry cleanup materials such as kitty litter or sawdust. To report serious spills, call 911.


Maintaining Vehicles & Equipment: Maintain and refuel vehicles and equipment at a single location on-site, away from the street, gutter and storm drains. Perform major equipment repairs and washings off-site. Inspect vehicles and equipment frequently for leaks, and prevent leaks from stored vehicles by draining gas, hydraulic oil, transmission, and brake and radiator fluids.



Ordering Materials & Recycling Waste: Reduce waste by ordering only the amounts of materials needed for the job. Use recycled or recyclable materials whenever possible. You can recycle broken asphalt, concrete, wood, and cleared vegetation. Dispose of hazardous materials through a hazardous waste hauler or other means in accordance with the construction permit. Non-recyclable materials should be taken to a landfill or disposed of as hazardous waste.

Concrete and mortar application Never dispose of cement washout into driveways, streets, gutters or drainage ditches. Wash concrete mixers and equipment only in specified washout areas, where the water flows into lined containment ponds. Cement wash water can be recycled by pumping it back into cement mixers for reuse.


For more information about construction BMPs, view or download these:


Construction BMP Brochures

Name of Document or LinkFile sizeDate Last Updated
Construction BMP Plan Sheet 590 KBJune 2014
Construction BMP Plan Sheet (CAD) 654 KBJuly 2017
General Construction and Site Supervision223 KBJune 2014
Heavy Equipment Operation115 KBJune 2014 
Roadwork and Paving100 KBJune 2014 
Fresh Concrete & Mortar Application127 KBJune 2014 
Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction-Related Activities1590 KB 
Earth-Moving and Dewatering Activities268 KB June 2014
Dewatering Best Management Practices (CALTRANS)  
Building Demolition and Mercury Hazards207 KB 
Riparian Erosion and Sediment Control brochure51 KB 
Landscaping, Gardening, and Pool Maintenance112 KB June 2014
Painting and Application of Solvents and Adhesives123 KB June 2014
Flyer: Requirements for Architectural Copper February 2012


Creek and Wetland Permitting

Projects that affect creeks, wetlands, and other water bodies have special permitting requirements, outlined by the brochure at the link provided below.

Guide to Creek & Wetland Permitting [530 KB]



Forms and Checklists

Name of Document or LinkFile SizeDate Last Updated
Construction Site Stormwater Compliance Inspection Form December 2012
Inspection Checklist-fillable PDF form December 2012
New Requirements for Construction Site Inspections December 2009
Conceptual Review Checklist for Stormwater Considerations38 kb 




Stormwater and Construction Poster (side 1) [299 KB]

Stormwater and Construction Poster (side2) [103 KB]


Additional Information


CASQA Construction Portal: The California Stormwater Quality Association provides information on construction BMPs in a web-based portal, which replaces its 2003 Construction BMP Handbook. Click here for information on purchasing a subscription to the portal.

For information about permanent stormwater controls, please see the New Development web page.