Just days before Covid-19 spurred a vast quarantine-at-home in California, a crew of workers in downtown Oakland was busily planting dozens of potted grasses, shrubs and trees in a newly sculpted garden bed in what had been a gutter and a row of parking stalls a block from City Hall.
The project was aimed at harnessing the cleansing power of plants and soil to treat polluted rainwater running into storm drains and ultimately into creeks and the San Francisco Bay.
“We’re really mimicking what watersheds looked like before development,” said Joshua Bradt of the San Francisco Estuary Partnership, which organized the series of rain gardens.
The project, known as the San Pablo Green Spine, takes its name from the series of four garden projects running along the San Pablo corridor, with individual street gardens located in the cities of El Cerrito, Berkeley, Emeryville and Oakland.
The landscaped planting beds are carved out of sidewalks and curbs, filling what had been asphalt and concrete with leafy green foliage. In Berkeley, the plot occupied a curb outside a busy McDonald’s where cars dodged in to the take-out window.
“The benefits are not just water quality but also greening the hardscape,” Bradt said, “making the sidewalk experience, or the pedestrian experience better.”
Bradt said storm water on roads deposits oil, insecticides and metals into storm drains which funnel into the Bay and creeks. He said the plants and soil serve as filters, where the pollutants become trapped in the dirt resulting in cleaner water.
“If this type of approach is used throughout the watershed,” Bradt said, “we’ll really be making really huge strides in minimizing the pollution that goes into he creeks.”
Although Bradt said numerous rain gardens would be needed to make a dent in the Bay Area’s stormwater pollution issue, the project is an illustration of how difficult that can be. The Estuary Partnership originally envisioned creating seven gardens along the 22-mile San Pablo span between Oakland and Rodeo. But a myriad of logistical and financial hurdles forced the group to scale back to four projects which ended up costing $4 million — a sum paid for by a coalition of groups and government agencies including the Association of Bay Area Governments and The Metropolitan Transportation Commission.
Bradt let his hands run over a soon-to-be-planted ginkgo biloba tree sitting in a tub in Oakland as hip hop music poured from a nearby sandwich shop. Unlike the other three projects, the Oakland site occupies an entire city — setting just a block just off Frank Ogawa Plaza.
Bradt said new clean water regulations will soon require Bay Area cities to adopt proactive steps toward cutting down on pollution running into storm drains. He hoped the regulations, as well as a growing awareness would inspire more cities to install the gardens on their roadways.
“If this was something that was done throughout the watershed,” he said “we would have a lot cleaner water.”