Stormwater runoff is part of a natural hydrologic process. However, land development and construction activities can significantly alter natural drainage patterns, resulting in polluted stormwater runoff.
Stormwater runoff is part of a natural hydrologic process. However, land development and construction activities can significantly alter natural drainage patterns, resulting in polluted stormwater runoff. Dirt and other materials from construction sites can harm local creeks and San Francisco Bay if not controlled.
All construction projects are required use Best Management Practices (BMPs) to protect soil from erosion, prevent sediment discharges, and use good site managment pratices to control other pollutants.
Small Construction Projects
If your project requires a permit from the local agency you may need to develop an Erosion Control Plan that describes the BMPs that you will take to prevent dirt and other materials from running off the site.
MRP Provision C.6 requires sites to implement the following categories of BMPs:
- Erosion Controls
- Run-on/Runoff Controls
- Sediment Controls
- Active Treatment Systems (if necessary)
- Good Site Management
- Non-Stormwater Controls
State Construction Stormwater General Permit
Projects disturbing one acre or more of surface, or less than one acre but part of a larger plan of development or sale, are required to obtain coverage under the State of California’s Construction Stormwater General Permit referred to as the CGP as well as obtain permits or approvals from the local agency.
Projects subject to the CGP must develop and implement a Stormwater Pollution Prevention Plan and implement a construction site monitoring plan. A qualified individual must prepare the plans. Refer to the State Water Board’s Construction Stormwater page for details.
Alert: The CGP was reissued in 2022 and went into effect on September 1, 2023.
Best Management Practices
Through its CASQA membership and subscription to the California Construction BMP Handbook, the Alameda Countywide Clean Water Program is making these BMP fact sheets available to local construction operators. The fact sheets are available for individual use and commercial reproduction is prohibited without written approval from CASQA. The full handbook and all the BMP factsheets are available from CASQA for a fee. The CASQA reference number is shown in parentheses.)
- Preservation of Existing Vegetation (EC-2)
- Hydraulic Mulch (EC-3)
- Hydroseeding (EC-4)
- Straw Mulch (EC-6)
- Geotextiles and Mats (EC-7)
- Silt Fence (SE-1)
- Sediment Basin (SE-2)
- Check Dams (SE-4)
- Fiber Rolls (SE-5)
- Street Sweeping (SE-7)
- Storm Drain Inlet Protection (SE-10)
- Active Treatment Systems (SE-11)
- Stabilized Construction Entrance (TC-1)
- Wind Erosion Control (Dust Control) (WE-1)
Good Site Management
- Material Delivery and Storage (WM-1)
- Material Use (WM-2)
- Stockpile Management (WM-3)
- Hazardous Waste Management (WM-6)
- Liquid Water Management (WM-10)
- Vehicle and Equipment Fueling (NS-9)
- Vehicle and Equipment Maintenance (NS-10)
Other Construction Guidance Documents