SF Civil
San Francisco Bay Area Civil
Engineering Design Firm
Email: sfcivil@yahoo.com
Phone: 1-(415) 723-0453
San Francisco Bay Area Stormwater Design
Stormwater plans, design, and reports vary by city/county within the bay area. Generally, the approach is to meet county/city standards in the most cost effective approach.
City of San Francisco Stormwater Design
San Francisco Preliminary Stormwater Control Plan and San Francisco Final Stormwater Control plan is required for projects creating more then 5000 square feet of impervious surface within the combined sewer area. In the separate sewer area, stormwater reports are required for areas creating more then 2500 square feet of impervious surface. The stormwater design in the combined sewer area, must reduce post condition stormwater flow and volume runoff for the 2 year 24 hour storm.
This is a project where the proposed building covers essentially the entire 5,500 square foot lot line. We reduced post condition runoff and volume by directing the stormwater that lands on the roof to a bioretention planter located on top of the second floor. Stormwater drains thru the planter and then flows to the combined sewer located in the street.
San Francisco Stormwater Design Example #1
San Francisco Stormwater Design Example #2
This option is used when there is not enough room on site to meet City of San Francisco stormwater requirements with planters or porous pavement. This option involves directing stormwater from the roof of the building to a tank located in the basement of the project. Stormwater in the tank is filtered and cleaned. Then stormwater is pumped from the tank and re-used for irrigation purposes, toilets, or showers. This option is more expensive and more maintenance then the example 1 listed above.
This project involved a new additional dwelling unit being added to the property. Stormwater design included directing stormwater to adjacent vegetated areas that then runs off into the street.
Alameda County Stormwater Design Example #1
San Mateo County Stormwater Design Example #1
This project involved an existing house being torn down and a new single family house being built on a 2600 square foot lot. San Mateo County has a policy that new construction can not create any additional stormwater runoff. San Mateo County stormwater design for this project involved creating a porous pavement concrete driveway in the front yard and adding a bioretention planter in the backyard. A San Mateo County Stormwater Report and San Mateo County Stormwater Plan was required for this project.
