How do I calculate the Flood Control flow data point? Do I need to know the post development design flows for my project?

If the watershed is small, you can use the Rational Method to calculate the design flow rate. If the area is large or you need hydrographs for designing a detention basin, the Flood Control District can calculate the hydrographs for you. You need to request a HYDRO6 submittal package. There is a fee for the District to calculate the flows for you. Contact Public Works Hydrology staff at (925) 313-2000 or email us and they can email the HYDRO6 instructions and submittal package to you. You may also purchase the submittal package at the front counter of the Public Works Department office at 255 Glacier Drive, Martinez, CA  94553.

Show All Answers

1. How do I calculate the Flood Control flow data point? Do I need to know the post development design flows for my project?
2. How do I determine the 25-year 24-hour storm depth
3. What are Pollutants of Concern (POCs)?
4. What are Stormwater Best Management Practices (BMPs)?
5. What is a Watershed?
6. What is an illicit discharge and who do I call to report it?
7. What is an NOI and what permits does it cover?
8. What is C.3?
9. What is NPDES and who oversees it?
10. What is the design storm for my project?
11. What is the difference between a Stormwater Pollution Prevention Plan (SWPPP) and a Stormwater Control Plan (SWCP)?
12. What is the difference between point source and non-point source?
13. What is the difference between the County Watershed Program and the Contra Costa Clean Water Program?
14. What is the difference between the storm drain system and the sanitary sewer?
15. What is the drainage easement across my property? Can I build on it? What can I do on it?
16. Who do I contact if I have flooding on my street?