SU0014807 - Laserfiche WebLink

Home Browse Search

Detention basin depths have been typically assumed to be eight feet as a general template for most proposed detention basins, including one foot of freeboard above the 100-year water surface elevation. An additional 20% has been added to the surface area of assumed excavation for the detention basins to account for setbacks and provision for vehicular access around them and to the lower areas to facilitate maintenance. A detention basin typical cross-section is shown below. Sizing will be based on Detention Basin section 3-4.05 of the San Joaquin County Improvement Standards published on November 2014. Storm drainage for the project will consist of a system of inlets, piping, and bio-treatment and detention ponds that will provide for storm water conveyance and treatment. As discussed above,two bio-treatment basins will be located on the northern portion of the project and will provide the treatment of storm water. A system of inlets and piping will discharge into the basin for treatment. A system of pipes will extend to the north and discharge the treated storm water to the detention basins located on the northwest portion of the project. Due to the soil characteristics and percolations rates,the stormwater discharged to these basinswill percolate into the ground. In large storm events, an agreement with BBID will allow for the metered discharge of the storm water from the detention basins to the existing canal bisecting the site. The storm water system will be designed to meet the following goals. • Assist new development in reducing urban runoff pollution to prevent or minimize water quality impacts. • Provide standards for developers, design engineers, agency engineers, and planners to use in the selection, design, and implementation of General Site Design Control Measures for Low Impact Design (LID) and appropriate site-specific source and treatment control measures. • Provide maintenance procedures to ensure that the selected control measures will be maintained to provide effective, long-term pollution control. Best Management Practices (BMPs) in the Storm Water Quality Control (SWQC) Manual will be implemented in the design of the Project, as appropriate,to reduce the directly connected impervious area and to promote a higher level of storm water quality. Below is a list of BMPs that shall be utilized in the Project Area: Source Control BMPs Biofiltration planters and Biofiltration swales for treatment of impervious areas and roof areas. Efficient irrigation to minimize runoff of excess irrigation water. Storm Drain Stenciling. Outdoor Material BMPs. Covered Trash Enclosures. Fueling Area BMPs. Page 6 of 7