Stormwater Management Program

Land development and construction activities significantly alter drainage patterns and contribute pollutants to urban runoff. During construction, erosion and removal of existing landscaping can create downstream impacts. After construction, impervious surfaces created by buildings, roads, and parking lots prevent storm water from directly percolating into the soil, and create an adverse impact on water quality. In fact, 80 percent of surface water pollution is attributed to urban runoff.

As the amount of impervious surface increases in a watershed, water that previously percolated into the soil and was filtered begins to flow directly to storm drains that lead to the Carquinez Straits without being treated. Untreated stormwater can be a source of pollutants, such as automotive fluids, cleaning solvents, toxic or hazardous chemicals, sediment, detergents, pesticides, and oil and grease.

With the growing concerns about urban storm water pollution, Federal and State environmental regulations require new and redevelopment projects to implement controls that treat polluted storm runoff before it reaches any receiving waters.

The City's Phase II Small MS4 General Permit
The City’s MS4 Permit requires the City and permit applicants to address storm water pollution issues in development of private and public projects. The requirements include implementation of Best Management Practices (BMPs) during construction and the use of post-construction controls to reduce pollutants discharged from the project site.

An Erosion and Sediment Control Plan (ESCP) or a Stormwater Pollution Prevention Plan must be prepared to address construction related impacts for the following project types:

  • All projects for a development, including, but not limited to a rezoning, tentative map, parcel map, conditional use permit, variance, site development permit, design review or building permit are required to submit an Erosion and Sediment Control Plan per Benicia Municipal Code Chapter 15.64
  • All projects required to obtain coverage under a State of California NPDES Construction General Permit (CGP)
  • All projects required to develop a plan to manage storm water drainage during construction per CALGreen 4.106.2 or CALGreen 5.106.1


Additionally, a Stormwater Control Plan (SCP) must be prepared for all projects that create or replace 2,500 square feet (SF) or more of impervious surface. The purpose of a SCP is to specify how the built project will incorporate site design characteristics, landscape features, and BMPs that minimize imperviousness, retain or detain stormwater, slow runoff rates, and reduce pollutants in post development runoff.

Best Management Practices (BMPs)

  • Keep trash and recycling cans covered to prevent litter from being blown away or scattered by foraging animals
  • When using power washers, carpet cleaners, cleaning paint brushes, etc. make sure to dispose of wastewater in a utility sink or sanitary sewer cleanout
  • Dispose of pet waste in the garbage
  • Use "green" gardening methods and plant native plants, protecting the soil and reducing the use of toxic pesticides
  • Use a broom and not a hose to clean up outside
  • Prevent over-watering by adjusting your sprinklers or irrigation system
  • Drain your swimming pools or spas into a sanitary sewer cleanout, not into a street or storm drain
  • Keep concrete, cement, dirt or mortar from blowing or flowing into the street or storm drain.  Do not wash tools or dispose of excess materials in the gutter or storm drain
  • Provide landscaping next to sidewalks and driveways to collect runoff off paved surfaces
  • Use "green building" materials and practices, such as pervious paving for projects
  • Clean up any toxic spills like motor oil, paint and antifreeze using an absorbent material.  Spills need to be cleaned up immediately and soiled absorbent disposed of properly
  • Use a commercial car wash or wash cars on a lawn or dirt surface.  Empty soapy water into a sink or toilet.
  • If you see litter, pick it up and put it in the trash can
  • When hauling by truck, enclose your loads or cover with a tarp


For more information, please call:  707-746-4240 Stormwater Hotline