Urban stormwater runoff is the single largest source of surface water pollution in Santa Barbara, according to city planners, and upgrades under way on MacKenzie Park’s parking lot aim to deal with that problem.
A passive treatment system for the runoff is being built and is expected to be completed by the end of October, said Cameron Benson, a restoration and water quality manager for the Santa Barbara Creeks Division.
Runoff from parking lots often contains pollutants such as hydrocarbons, sediments, metals, nutrients and bacteria.
“This is a way to capture and treat that water,” Benson said.
The city has been installing permeable pavers in the lot, which will allow water to pass through them into a subsurface gravel layer that doubles as a storage and infiltration area and a structural base layer. Water then will be allowed to soak back into the soil, just as it did before the development was built.
There’s no energy cost involved to treat the water, either.
“It’s a tacit natural treatment method,” Benson said.
The project is designed to capture and treat the volume of stormwater generated from a 1-inch, 24-hour storm event.
The project is estimated to cost $524,000, and is coming from the Creeks Division Capital Fund.
All trees in the park will be unaffected by the project, and parking in the lot off Las Positas Road will increase to 75 spaces from 69, Benson said. The city’s Facilities Division is also working on the project to put in asphalt, while the Creeks Division has put in the permeable pavers.
If the project works as well as planned, Benson said, it could be replicated in other parking lots that need to be retrofitted.