During construction, uncontrolled stormwater runoff can contribute excess sediments to the storm drainage system and local waterbodies. Other pollutants can also be generated at construction sites, such as paints, solvents, trash, metals and concrete slurry. The Construction Activities Program works with developers to ensure proper implementation of good housekeeping and erosion and sediment control measures.
City activities under the Construction Activities Program include:
- Outlining the development application process, submittal requirements, activities required during construction, and providing compliance guidance
- Reviewing and providing comments upon all land development applications and construction documents
- Holding workshops for City staff and developers
- Requiring and reviewing Grading Plans for projects that involve grading.
- Requiring and reviewing all projects that disturb any soil for appropriate Erosion and Sediment Control and good housekeeping plans
- Requiring and reviewing Stormwater Pollution Prevention Plans (SWPPPs) for applicable projects
- Conducting inspections of all active construction sites
In addition to complying with the City’s requirements, construction projects disturbing one acre or more need to obtain coverage under the State Water Resources Control Board's General Construction Stormwater Permit. Failure to obtain a permit directly from the State could result in non-issuance of a building or grading permit, notices of violation, and may lead to significant fines. The general construction permit (CGP) requires preparation of a SWPPP. The CGP requires construction sites to conduct regular inspections of erosion and sediment control measures before, during, and after storm events to maintain these measures and monitor for pollutant discharges. Regular monitoring also includes implementation of good housekeeping measures on site.
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.
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.
- See the Engineering Development Guidance (PDF) handout to determine what permanent site measures might be applicable to your project:
- Reviewing site plans for consistency with new development standards.
- An inspection program to ensure post-construction measures are implemented and maintained.
More information on the State Construction General Permit.
Forms and Handouts
- Concrete and Mortar Best Practices (PDF)
- Roadwork and Paving Best Practices (PDF)
- Development Application Submittal Requirement for Stormwater Quality
- Paint Best Practices (PDF)
- Construction Activities Practices (PDF)
- Landscape Renovations Practices (PDF)
- City of Davis Building Division Forms
- Yard Material Management (PDF)
- Pool and Spa Maintenance (PDF)
State of California
- Bay-Delta Ecosystem Restoration Program (CALFED)
- California Green Building Standards Code (CALGreen)
- Central Valley Regional Water Quality Control Board
- Department of Water Resources
- Environmental Protection Agency
- Stormwater Regulations
- State Water Resources Control Board