On Saturday July 16th, the public and members of Surfrider's Ocean Friendly Gardens program met with Cammie Ingram of Scripps Institute of Oceanography to tour the exciting new landscape changes on campus.How we treat our landscaping can have a significant impact on our natural environment, including the ocean. Pesticides and Herbicides applied to our gardens can be washed away into our storm drain system. Overspray from sprinklers can also pick up oil and heavy metals from car exhaust and brake pads while running along the gutters and into the storm drain. Water that enters our storm drain system when it is not raining is known as a dry weather flow and can carry high concentrations of pollutants. Water that enters our storm drain systems is not usually treated before discharging to our creeks, bays, and ocean. By reducing the number of pollutants in our yards and stopping the overwatering that carries pollutants into our waterways, we can help keep our ocean healthy.
For this event, participants met at Scripps pier, and got a chance to learn about how the campus has been working to implement OFG's concept of garden "CPR" - Conservation, Permeability, and Retention - as a way to reduce water pollution.
Scripps has been implementing conservation by removing unnecessary lawn areas and replacing them with native and other low water use plants. The native plants, once established, will help control erosion on the many slopes found throughout the campus. They also provide much needed habitat for native wildlife that are often displaced due to residential and commercial development. Native butterflies, bees, and birds are just a few animals that rely on native plants for food and shelter. A significant amount of lawn has already been removed, and more conversion is planned in the future. Additional benefits from using native plants include lowering to eliminating the need for fertilizers and pesticides, less pollution from gas powered maintenance equipment, and reducing the amount of yard waste that must be transported to and processed at the landfill.Permiability is achieved by having healthy biologically active soil, and by reducing the amount of impervious surfaces (such as concrete and asphalt). Due to safety and transportation requirements on a large campus like Scripps, it can be difficult to incorporate pervious hardscape like unit pavers. One way to use impervious surfaces but still
allow for water to permeate into the soil is by directing runoff from impervious surfaces like streets and walkways into a landscaped area rather than allowing the water to directly enter the storm drain system.Retention is being achieved by the installation of rain gardens, bioretention areas (see picture above), and rain barrels (see below). Rain gardens and bioretention areas have been installed throughout the campus as a way to retain water from the surrounding slopes and hardscape. By allowing the water to pool in these areas, water percolates into the soil rather than directly entering the underground storm drain system. The resistance caused by the vegetation also slows down the surface water which can help reduce erosion.
Rain barrels can collect stormwater runoff from the roofs of buildings and later be used to water nearby plants.Another water treatment feature recently installed at Scripps is an "ecology embankment'. This large series of media filters directly along the beach treats dry weather flows and the "first flush" of stormwater flows, which typically contain the highest concentration of pollutants during a storm event. These filters are connected to the underground storm drain system which collects the flows that cannot be retained by the landscaping. While studies have shown media filters to be effective at treating a large variety of pollutants including bacteria, these "end of pipe" treatment systems can be very expensive. Also, their long term effectiveness and maintenance costs are relatively unknown. Scripps plans to closely monitor the effectiveness of the media filters through ongoing water sampling. OFG hopes that through the implementation of CPR throughout our landscapes, from the smallest residential yard to a large campus like Scripps, we can eliminate the need for these large and costly structural treatment devices in the future.
A big thanks to Cammie Ingram from Scripps for providing such an informative tour. OFG hopes to work closely with Scripps in the future to help them meet their water conservation and pollution prevention goals though their landscaping. To learn more about the stormwater treatment devices installed at Scripps, you can read the story featured in the San Diego Union Tribune. If you would like to participate in future OFG garden events and/or learn more about our program, please continue visiting our blog and "like" us on Facebook at 'Ocean Friendly Gardens San Diego'.
