Regional Storm Capture Facility Going to Ground
With rains overwhelming local drains in late October, the visible construction progress over the summer on Orange Memorial Park, a regional stormwater capture facility in South San Francisco, seems timely.
More than 6,500 acres of the Colma Creek watershed, in six municipalities, drain through the new regional facility. The facility, scheduled for completion in 2022, includes trash screens, a sediment removal chamber, and a giant storage basin under sports fields. It is designed to filter pollutants in runoff, percolate groundwater, and irrigate local parks and trailsides (offsetting potable water demand).
Former San Mateo County stormwater director Matt Fabry calls it “An ambitious multi-benefit project with water quality and resilience benefits.”
Areas sensitive to erosion on the half-constructed park weathered the recent atmospheric rain event under tarps and behind silt fences.
Current construction activities for the complex stormwater capture project are focused on excavation of a large subsurface drainage system. Crews recently installed modules for a 1.4 million gallon-below-ground cistern and infiltration gallery, and are working to connect pipework, maintenance ports and manholes. Installation of the modules will continue into November, followed by back filling of the entire system.

Two parts of the project located within Colma Creek, including a trash and sediment capture system (aka grit filter), required permits from the Peninsula’s fledgling Sea Level Rise and Resiliency District, US Fish and Wildlife, and the Regional Water Quality Control Board. Work in the creek also required completion before October 1 to avoid disturbing birds nesting in the riparian zone. Surface restoration will be a next step.
“We had to switch regulatory gears mid-permitting from the county flood district to the new sea level rise and resiliency district,” says project manager Bianca Liu, from the City of San Francisco. “There’s a lot of eyes on us because this the first regional scale stormwater capture and green infrastructure project, and it sets a precedent for the future.”
Project costs are $15.5 million, bankrolled by Caltrans and local jurisdictions to fulfill stormwater management mandates and mitigate for trash, PCBs, and other polluted runoff to the Bay. The project also optimizes water use and groundwater recharge in times of drought.
“When the capture basin is full, we’ll be putting the excess, clean water rather than dirty water, back into the creek,” says Liu.
The project is one of a variety of multi-partner initiatives to improve water quality and flood capacity along Colma Creek, including projects still in proposal stages inspired by the 2018 Resilient by Design Bay Area Challenge vision for the Colma Creek Watershed.
With Orange Memorial Park under construction, meanwhile, the debate over how to optimize infrastructure investments far into the future now has one tangible new example.
“This wasn’t your typical infrastructure project, the regional scale created a lot of challenges in permitting, funding and interjurisdictional decision-making. Our next challenge will be how to collaborate on O&M,” says Liu, referring to operations and maintenance responsibilities and budgets that no municipality wants to shoulder alone.
Keeping the new park and its complex underground hardware working far into the future won’t be cheap. But kids will be able to kick and bat balls on sports fields on top of the stormwater basin by 2023.
Other Recent Posts
Citizen Methane
Methane, a potent greenhouse gas, leaks from abandoned wells across the country. Curtis Shuck has been finding them by hand, well by well. But finding the leaks is where satellites and citizens come in.
Imprisoned with Climate Change
Climate change has a disproportionate impact on incarcerated Americans. Juan Moreno Haines, one of 2.3 million prisoners in the US, describes his experience.
Artists Circle Confronts Climate Displacement and Just Recovery
The climate crisis in driving the displacement of people around the world. In the midst of the pandemic, an artists circle began developing new approaches to the issue.
Future-Proof Homes?
Oona Khan dreams about her home of the future, after losing her Malibu retreat to fire. Caught in a quagmire of legal battles with Southern California Edison, and surging construction costs, Khan is still waiting to start construction.
The Case for Climate Castles
As climate change throws more extreme events at us, isn’t it time to think bigger, bolder, further ahead? Six young architects draw climate-resilient castles.
Looking for Justice at the Nexus of Housing and Climate Policy
How housing is built and who it is built for are not only equity questions, but also climate mitigation questions. When people can afford to live near their jobs, their emissions from commuting go down.
Bittersweet Beach Outing to See King Tide
On a clear morning in January, a group of tide worshippers gathered at the Santa Monica Pier to “celebrate the ocean and build our climate community,” said Laurene von Klan.
Safer at School from Wildfire Smoke?
Research confirms the drastic impacts wildfire smoke has had on school learning. But 16 East Bay schools now have updated air filters and more actions are in the pipeline statewide.
My Neighborhood Wised Up to Fire
When we fled the house in the Santa Cruz mountains that we had been living in for just nine months, we knew exactly two of our neighbors.
Extremes-in-3D
In Part 1 FIRE, KneeDeep explores where to expect debris flows from burn scars, how one neighborhood became fire wise, and what schools are doing to become safe havens.