Across the Central Valley, similar projects are in development, he says. Cost is a limitation — the board’s recommended flood protection measures, including projects like Dos Rios, have an estimated price tag of $25 to $30 billion. But those measures could avoid around $1 trillion damage from major flooding. The permitting process can also be slow and a hurdle. But Johnson says there’s a lot of opportunity to develop similar floodplain habitat restoration projects across the valley.
“In order for it to work at a system-wide scale, we want to be doing it in a bunch of different places,” Johnson says.
Floodplain restoration can also help California weather drought, which is predicted to become more intense with climate change, according to Cain. Not only does growing native vegetation require less water than agriculture, when floodwaters spread across the land, the water seeps down into the groundwater, recharging overdrawn aquifers.
For all its benefits, this type of floodplain restoration isn’t appropriate everywhere, according to Joshua Viers, a watershed expert at University of California, Merced. Dos Rios is well-suited because the confluence of the two rivers makes for dynamic conditions that are particularly good for habitat restoration. In other parts of this heavily agricultural region, other approaches may be more appropriate, he says. Certain crops, like grape vines, can handle some flooding, which also benefits groundwater stores. Some types of farming can be incorporated into habitat restoration; rice fields can support salmon. According to Viers, using a range of different approaches can help manage flooding and support ecosystems along California rivers.
“You can’t do all things in all places,” Viers says. “If you can string these together, you can have mutually reinforcing benefits.”
There are also social benefits to habitat restoration: Through the Grayson United Community Center, Lomeli-Gil has been working to engage Grayson residents with Dos Rios and surrounding restored natural areas. Several locals have gotten jobs with River Partners planting vegetation. And now, California State Parks is aiming to open the new state park to the public later this year.
“It’s in our backyard, so how blessed will we be,” Lomeli-Gil says.
As other floodplain projects are in development across California, Dos Rios is still expanding.
Cain walks along furrows on a plowed field on former farmland adjacent to Dos Rios. Instead of crops, this plot will soon be planted with young native trees and shrubs. Cain checks little white labels on sticks that mark where each new plant will go: a Modesto ash, box elder, and, his favorite, elderberry.
Cain and his colleagues at River Partners have set a long-term goal of restoring 100,000 acres in the San Joaquin Valley. That would restore about 10 percent of the wetlands that used to be in this area.
On the other side of the bare field, two large wonky Vs of Aleutian cackling geese fly by. Even though they are hard to see from such a distance, their characteristic honks echo across the field.
Dos Rios flooding images and videos are courtesy of River Partners.