San Mateo County officials are moving forward on a green infrastructure plan that aims to transform the urban landscape and storm drainage systems.
The plan will help the county transition from relying solely on traditional drain infrastructure, which allows stormwater to flow directly into drains and bodies of water, to a more environmentally friendly model that disperses runoff to vegetated areas and collects it for nonpotable uses.
At a May 22 meeting of the Midcoast Community Council, Joe LaClair, planning services manager for San Mateo County, outlined the new workplan. The document was approved by the Board of Supervisors in 2017 and submitted to the San Francisco Bay Regional Water Quality Control Board later that year. The project is a collaborative effort, led by the county’s Office of Sustainability, to meet recent state regulatory requirements for reducing pollution.
Several years ago, LaClair said, San Mateo County officials were tasked with preparing a workplan for incorporating green infrastructure throughout the county. In 2015, the regional water quality control board established a new permit that regulates pollutants in the runoff from municipal storm drain systems. The permit also requires that the county, and all of its cities, prepare a plan to shift from traditional “gray” storm drain infrastructure to “green” infrastructure.
“Gray infrastructure (refers to) streets, gutters, sewers and pipes,” said LaClair. “Basically, plumbing systems that move the water quickly from paved surfaces to receiving waters like creeks, streams and the ocean.”
The goal of the project, LaClair continued, is to have that water move through man-made systems, such as soil and plant areas, to treat it before it goes into other bodies of water.
“Essentially, it captures and treats stormwater using (these) specially designed landscape systems,” he said. “You can see all of these features where the water passes from paved areas into a treatment system (like street planters and curb extensions) before it then gets into a pipe and goes into a stream.
“Sometimes it may be groundwater recharge,” he added. “So, it may not be connected to a pipe that goes to a stream. It may just percolate in the ground.” LaClair said that examples of green infrastructure already exist along the coast, driven by concerns about water control near the Fitzgerald Marine Reserve. There have been improvements made on Carlos Street to take water from the parking lot before redirecting it to landscaped treatment areas.
LaClair also said that the plan also establishes modeling, monitoring and reporting mechanisms to keep track of the county’s green infrastructure development. That information will then be relayed to the San Francisco Bay Regional Water Quality Control Board.
The requirements call for the workplan to be submitted to the regional water board by Sept. 30. For more information, visit www.smcsustainability.org.