Stormwater C.3 Guidebook
Guidebook
Stormwater C.3 Guidebook. 4th Edition (September 2008, 1.6 MB .pdf)
Staff Report describing changes from the 3rd Edition (September 2008, 165KB .pdf)
October 2009 Supplement to the 4th Edition
The supplement includes design sheets for two new IMPs and an updated table of factors and equations to be used for sizing IMPs (311KB .pdf).
Additional Guidebook Resources
IMP Sizing Calculator
Updated for the Stormwater C.3 Guidebook 4th Edition. Released October 2009. Calculator and setup file (3MB .zip). After installing the calculator, read the help file.
Appendix A: Local Exceptions and Requirements
Follow the link to the local municipality website:
- City of Antioch
- City of Brentwood
- City of Clayton
- City of Concord
- Town of Danville
- City of El Cerrito
- City of Hercules
- City of Lafayette
- City of Martinez
- Town of Moraga
- City of Oakley
- City of Orinda
- City of Pinole
- City of Pittsburg
- City of Pleasant Hill
- City of Richmond
- City of San Pablo
- City of San Ramon
- City of Walnut Creek
- Contra Costa County
Appendix B: Soils, Plantings, and Irrigation for Bioretention Facilities
Appendix (January 21, 2009, 337 KB .pdf).
The following suppliers have submitted a soil sample and test results to the Program. Acceptance of materials for a specific project is at the discretion of the local municipal inspector.
IMP Sizing Calculator
You will need to download the IMP Sizing Tool file and the Setup.exe file to the same directory. Then open Setup.exe to complete the process.
Guidance for HSPF Modeling
For compliance with flow-control requirements using Option 3 (memo 763 KB .pdf)
Basic Geomorphic Assessment Methods and Criteria
For compliance with flow-control requirements using Option 4b. Contact the Program to obtain a copy.
Contra Costa Hydrology Data
- Isohyetal Map (Drawing B-166), 11" x 17", Low Resolution, 630 KB .pdf
- Isohyetal Map (Drawing B-166), 11" x 17", High Resolution, 10.6 MB .pdf
- Chart: Unit Basin Storage Size for 80% Capture. 8½" x 11", 17 KB .pdf
- Contra Costa Hourly Rainfall Data (for continuous runoff simulation modelers) 1 MB .zip
Example Stormwater Control Plans
Please note these example plans were prepared in compliance with previous editions of the Stormwater C.3 Guidebook. They are made available as examples for format and presentation.
- Stormwater Control Plan for the Nove Property (158 KB .pdf)
- Nove Property Exhibit (4 MB .pdf)
- Stormwater Control Plan for Almondridge residential subdivision (741 KB .pdf)
- Stormwater Control Plan for Rose Garden commercial development (668 KB .pdf)
- Rose Garden Exhibit (1.4 MB .pdf)
Operation and Maintenance of Stormwater Facilities
Forms
The following documents are in MS Word and may be incorporated into Stormwater Facilities Operation and Maintenance Plans. See Chapter 5 of the Stormwater C.3 Guidebook, Fourth Edition
- Designation of Responsible Individuals
- Stormwater Facilities Inspection and Maintenance Log
- Sample Contents of Stormwater Facilities Inspectors Report
Operation and Maintenance Fact Sheets
The following fact sheets provide general information on maintenance of stormwater facilities. In the Stormwater Facilities Operation and Maintenance Plan, this information should be augmented with information specific to the facility and the site.
- Fact Sheet for Bioretention Facilities
- Fact Sheet for Planter Boxes
- Fact Sheet for Dry Wells
- Fact Sheet for Wet Ponds, Constructed Wetlands, and Extended Detention Basins
Example Operation and Maintenance Plans
The following plan is provided as an example. Requirements tend to be project-specific and should be discussed with staff of the municipality having jurisdiction.
- Operation and Maintenance Plan for the Paulson Lane Subdivision (8 MB .pdf)
- Stormwater Facilities Operation and Maintenance Matrix for the Paulson Lane Subdivision (76 KB .doc)
