University of California, San Diego
OP-23: Rainwater Management

In accordance with UC San Diego’s Phase II Small MS4 General permit, construction projects that create and/or replace 2,500 square feet or greater of impervious surface are required to include specific site design requirements and Low Impact Development (“LID”) design standards. These standards emphasize landscape-based site design features and provide multiple benefits in addition to storm water runoff and pollutant load reduction (e.g., shading from trees, wildlife habitat from stream setbacks, reduced need for pesticides and irrigation from soil quality improvement).

UC San Diego also complies with the General Permit for Storm Water Discharges Associated with Construction Activity which requires construction projects 1 acre in size or greater to implement Low Impact Development (LID) design features to ensure there is no net increase in overall site runoff and to match pre-project hydrology by maintaining runoff volume and drainage concentrations. To offset increases in impervious surfaces from roofs and paved surfaces, LID Best Management Practices (BMPs) such as bioretention cells and rain gardens are used.

- Replaced turf with stormwater treatment landscaping at two locations on campus to reduce irrigation, prevent non-storm water flows, and treat stormwater runoff from roads and a parking lot. The Revelle Parking Lot Retrofits include turf removal and bioretention areas to collect and infiltrate stormwater runoff from the lot. At the second location, turf will be replaced with drought tolerant landscaping and a bioretention basin to reduce stormwater runoff and the discharge of pollutants. Removal of the turf and installation of bioswales will require excavation, removal of parking areas and curbs, installation of bioswale liner, fill, perforated piping, and concrete edging, installation of plantings and irrigation for berms, and construction of cleanout and curb inlet.

- Modular Wetland Treatment System and Monitoring: We have installed a Modular Wetland Stormwater Treatment System at the UCSD Nimitz Marine Facility. The system will treat stormwater runoff from a concrete swale that discharges directly into the San Diego Bay. Installation of the modular wetlands will include excavation, placement of the modular vault, and discharge connection to a stormwater pipe.Monitoring of storm water runoff upstream and downstream from this system will be performed to evaluate the effectiveness of this system at removing heavy metals and sediment from runoff. Effectiveness monitoring will be done to evaluate the concentrations of heavy metals and TSS in the stormwater runoff before and after it goes through the treatment system.

- Replaced turf with stormwater treatment landscaping at two locations on campus to reduce irrigation, prevent non-storm water flows, and treat stormwater runoff from roads and a parking lot. The Revelle Parking Lot Retrofits include turf removal and bioretention areas to collect and infiltrate stormwater runoff from the lot. At the second location, turf will be replaced with drought tolerant landscaping and a bioretention basin to reduce stormwater runoff and the discharge of pollutants. Removal of the turf and installation of bioswales will require excavation, removal of parking areas and curbs, installation of bioswale liner, fill, perforated piping, and concrete edging, installation of plantings and irrigation for berms, and construction of cleanout and curb inlet.

UC San Diego’s Storm Water Management Program is designed to reduce the discharge of pollutants “to the maximum extent possible.” Minimum control measures include public education and participation, elimination of illicit discharges, construction site storm water runoff control, post-construction site storm water management, and pollution prevention for municipal operations. The storm water management program on campus includes: (1) design guidelines to incorporate storm water treatment controls into new development to improve the quality of storm water runoff and to ensure that post construction runoff volumes do not exceed pre-construction values (no net gain); (2) storm drain markers so students, staff, faculty, and the public are aware that these drains discharge directly to the ocean and that only storm water should go into them; (3) a “Best Management Practices” handbook for outdoor work activities with guidance on how to prevent pollutants from going into storm drains and into the ocean; (4) training/outreach on storm water pollution prevention; (5) innovative engineering controls such as media filters and bioswales to remove pollutants from storm water run-off and to prevent dry weather flows such as irrigation run-off or wash water from going into storm drains; and (6) spill prevention and response resources (spill kits) and training to prevent an outdoor spill from going into a storm drain. UC San Diego has also formed valuable partnerships with the City of San Diego, Urban Corps of San Diego, San Diego Coastkeeper, Miocean, and the State Water Resources Control Board to implement multiple storm water pollution prevention projects to protect our ocean resources.