Stormwater Quality for New Development and Redevelopment

Runoff from areas being developed or redeveloped can significantly affect receiving waterbodies. As runoff flows over areas altered during development, it picks up pollutants such as sediment, oil and grease, pesticides, heavy metals, and nutrients (e.g., nitrogen and phosphorus). Additionally, development can increase impervious surfaces (e.g., parking lots, driveways, and rooftops) which prevent rainfall from being absorbed into the ground. Instead, stormwater is collected and routed to the stormdrain system where large volumes of runoff quickly flow, carrying pollutants to nearby waterbodies.

See the Engineering Development Guidance (PDF) handout to determine what permanent site measures might be applicable to your project.

The City strives to reduce the impacts associated with new development/redevelopment by:

• Establishing standards that require the implementation of post-construction measures to lessen the long-term impacts of stormwater discharges from new development and redevelopment. The standards apply to all types of development projects, including new roadways, with the exception of a single-family residence:

• Site Design measures for any project or any land use other than a single-family residence, that creates or replaces 2,500 square feet or more of impervious surfaces. These projects are required to incorporate one of the following measures:

(a) Stream Setbacks and Buffers
(b) Soil Quality Improvement and Maintenance
(c) Tree Planting and Preservation
(d) Rooftop and Impervious Area Disconnection
(e) Porous Pavement
(f) Green Roofs
(g) Vegetated Swale
(h) Rain Barrels and Cisterns

Projects must provide a calculation to show that runoff has been reduced by implementing one of the above measures.

• Regulated projects, which are any other land use (other than a single-family residence) that creates or replaces 5,000 square feet of impervious surfaces, must provide Site Design Measures, Source Control Measures, Treatment Control Measures and/or Bioretention Measures on site.

• Hydromodification: are any project that creates or replaces 1 acre or more of impervious surfacing must also provide everything a regulated project requires and detention for the 2 year 24 hour rain event.

• Reviewing site plans for consistency with new development standards.
• An inspection program to ensure post-construction measures are implemented and maintained.

Forms and Handouts

• Development Application Submittal Requirement for Stormwater Quality
• City of Davis Stormwater Phase II General Permit Development Standards Guidance Document (PDF)
• Stormwater Pollution Prevention: Concrete and Mortar (PDF)
• Stormwater Pollution Prevention: Painting (PDF)
• Stormwater Pollution Prevention: Construction Activities (PDF)
• Stormwater Pollution Prevention: Landscape Renovations (PDF)

Helpful Links

State of California

• Bay-Delta Ecosystem Restoration Program (CALFED)
• Central Valley Regional Water Quality Control Board
• Department of Water Resources
• Environmental Protection Agency
• Stormwater Regulations
• State Water Resources Control Board
  • Phase II Small MS4 General Permit Development Standards Guidance Document (PDF)

Federal

• EPA Menu of SW BMPs
• Federal Stormwater Regulations

California Stormwater Quality Association (CASQA):

• CASQA
• New Development and Redevelopment BMP Handbook

Other

• California Native Grasslands Association
• River-Friendly Landscaping  
• UC Davis Arboretum