The City of Santa Barbara has finished Mission Creek restoration at Oak Park, bringing the creek back to its natural configuration by removing concrete structures in the creek bed to allow for more water to flow through the creek and prevent erosion. 

The restoration process also included removing non-native plants and replacing them with more than 3,000 native plants and trees. 

Removing the aging concrete structures means the creek channel can provide improved shelter and access for wildlife. The native trees will help keep the creek cool while the native plants naturally filter out pollutants in the water, according to city staff.   

The total project cost was $814,231 and was funded through Measure B, the transient occupancy tax for guests staying in a hotel or vacation rental in Santa Barbara. 

On Wednesday, the city celebrated the end of the project by inviting staff and neighbors to the park to learn about the work. 

“This is an area surrounded by multifamily units, so this is the de facto open space for a lot of folks that live in this part of town,” Mayor Randy Rowse said.

Project manager Tim Burgess said that throughout the park’s history, infrastructure had been put in the creek to stabilize the banks; however, that infrastructure wasn’t effective in the long run. 

Part of the project included removing a stacked concrete wall. Burgess said they aren’t entirely sure why the wall was placed there but that it was likely to protect an electric meter that was on top of the bank but has since been relocated. 

Burgess said the concrete wall did temporarily prevent erosion and protect the creek beds but eventually led to more problems. 

“Last winter, we had really high flows, and the water came up against this wall, and it wasn’t able to really expand out, and the velocities really rip through here when you’ve got a narrow creek channel,” Burgess said. “If those velocities can’t erode along the side of the bank or really spread out, then they’re going to start to erode downward and down cut into this creek channel.”

Burgess said that as the creek eroded, more concrete got poured into the creek. 

“Effectively, over time, we end up with a deeper creek channel, and as that creek channel deepens, you get more bank erosion. It’s almost like a feedback loop,” Burgess said. 

To stabilize the creek, they started removing the concrete and replacing it with big rocks and trees that will stabilize the soil and create a more mobile creek bank. The hope is that when water comes through the creek, the flow will be slower, preventing future erosion.

Erin Markey, manager of the city’s Creeks Division, said the project was about restoring the creek as a habitat for plants and wildlife and bringing it back to its historical use. 

“In this case, we’re trying to improve the health and function of the creek in the riparian habitat along the creek here,” Markey said. “Creeks are a really important resource for our community. They provide recreational activities, and they’re the most important wildlife habitat that we have.”

Markey also said that improving the health of the creek will have a positive impact on the water quality downstream and in the ocean.