Floods Show California’s Climate Dilemma: Fight the Water, or Pull Back?

Beth Salyers, the deputy district engineer for the Corps’ Sacramento District, which includes much of the central and northern part of the state, said her agency was increasingly embracing what she called “engineering with nature.”

“As we do our flood projects, ecosystem restoration is something that we’re starting to see incorporated,” Ms. Salyers said. “As time goes on, we learn and we grow.”

It’s not clear how much the Corps’ stated support has translated into flood management projects.

Efforts to pull levees back from rivers face big challenges. To complete the setback levee project in West Sacramento, the city had to relocate roughly a dozen households near the river, said Paul Dirksen, the flood protection planner for the city. Some of the negotiations with property owners were tough.

Mr. Dirksen remembers one case particularly clearly. “It was a grand house,” he said. “And that person thought that they were going to live there for the rest of their life. So they had a lot of emotion around that.”

Local officials in California can be reluctant to take farmland near rivers out of production, said Julie Rentner, president of River Partners, an environmental group that works on floodplain restoration projects in the state. “Land that’s making a product like milk or almonds or walnuts pays higher property taxes than land that’s providing wildlife habitat and flood relief,” she said.

River Partners played a key role in creating the Dos Rios Ranch Preserve, a 2,100-acre floodway expansion near the confluence of the San Joaquin and Tuolumne rivers. The area was once a dairy and cattle operation but is now a verdant habitat for birds and fish. If the rivers overtop their banks, water can inundate the plot safely, reducing flood risk downriver.

The project took years to complete, though, and lots of delicate work to cobble together government funding, Ms. Rentner said. It was 2006 when River Partners began working on buying Dos Rios Ranch from the family that owned it, she said. The deal closed in 2012.