Preventing Storm Water Pollution at Construction Sites

The most common pollutant from construction sites is erosion, where large amounts of sediment-laden water have the potential to flow into storm drains. The property owner is the legally responsible person (LRP) and must ensure that any water that leaves the construction site meets the minimum requirements for water quality. This means that pollution prevention best management practices (BMPs) such as wattles, silt fencing and gravel bags are strategically placed to prevent sediment and other pollutants from entering the storm drains. While most of the rainfall in Sonoma County occurs between October 1st and April 30th, pollution prevention is a year-round activity. Maintaining these BMPs helps protect the health of our waterways and our community. 

Here is an example of what a properly maintained construction site might look like:  

All construction sites are required to submit their plans to the Building Department for approval before permits are issued and before any construction begins. 

• Construction sites <1 acre of land disturbance are required to prepare a simple Erosion and Sediment Control Plan (ESCP), which can be prepared and signed by the property owner or their contractor. See template below.
• Construction sites >1 acre of land disturbance are required to prepare a Storm Water Pollution Prevention Plan (SWPPP), which must be prepared by a Qualified SWPPP Developer (QSD) and signed by the property owner.   
• All projects must implement and maintain proper BMPs.

All construction sites are subject to inspection by the Town or North Coast Regional Water Quality Control Board. 

The North Coast Regional Water Quality Control Board Construction General Permit Order 2009-0009-DWQ has been administratively extended until a new order is adopted and becomes effective.

Documents & Resources 

ESCP Template for Sites <1 Acre 

Storm Water BMPs for Small Construction Sites

Storm Water BMPs for Larger Construction Sites

California State Water Board Construction Stormwater Program

Frequently Asked Questions regarding the State requirements for the Storm Water Construction General Permit

Watch this short video for an overview of the storm water Construction General Permit from the California State Water Resources Control Board.

ESCP or SWPPP Review Checklist-Town of Windsor

Site Inspection Form