It’s a race against time.
With climate scientists warning of a “super” El Niño this year that will dramatically increase the risk of Delta flooding, work to reconstruct one levee protecting some of Stockton’s toniest neighborhoods is hastily proceeding.
The goal is to finish the work by the end of October — right around the start of storm season.
“It’s looking good,” said Darren Suen, executive director of the San Joaquin Area Flood Control Agency, who has been following the progress carefully.
The project focuses on a one-mile stretch of Tenmile Slough. The job includes rebuilding the levee to make it more stable and installing an impermeable “slurry wall” barrier to keep water from seeping through and a rock-covered slope that will prevent erosion. The work, which began in April 2025, is intended to protect Brookside neighborhood homes and businesses at risk of flooding.
The larger Lower San Joaquin River Project, as it’s called, encompasses levees that protect 71,000 acres that are home to 264,000 residents, and homes and businesses valued at $21 billion, the agency estimates.
The Tenmile Slough work is part of the initial phase of a comprehensive effort to rebuild 24 miles of levees around Stockton. Completion of all projects isn’t expected until 2039, depending on funding.
The work is critical to protecting Stockton from flooding disasters that have ruined homes and businesses over the last century. The city saw major floods in both 1955 and 1958 and again in 1997.
The $2 billion construction comes amid predictions that this year’s El Niño could be a doozy.
The National Weather Service’s Climate Prediction Center issued a forecast Aug. 13 saying there’s a 90% chance of a “very strong event” this season. It is expected to be so intense that there is a “69% chance of a historic event that would exceed the strength of previous El Niño events dating back to 1950.”
Such vicious storms would be horrendous, but not unprecedented. The worst was the Central Valley “megaflood” of 1861-62. At that time, it was reported that 98.4 inches of rain fell over 43 days. The San Joaquin Valley became a virtual inland sea, and 1,000 people were reported to have been killed as a result.
Suen told Stocktonia that he’s well aware of predictions of an especially strong El Niño weather event this year. But he says that forecast doesn’t necessarily mean San Joaquin County will be hit hard.
Past El Niño have socked some regions while others remained relatively dry during the season-long event, he said.
Still, it doesn’t take much to bring flood threats to the Central Valley. Last season, Stockton and other parts of San Joaquin County were under back-to-back flood watches in December and January. And those were in the face of an unusually dry and warm winter that created alarmingly low snowpack levels across the Western U.S.
And the region’s levees already reflect a nationwide problem: The infrastructure is getting older while weather is getting more extreme.
Two years ago, in October 2024, a levee failure in western San Joaquin County prompted officials to declare a local state of emergency. Reclamation District engineers found slumping along the Old River on Victoria Island, near Highway 4, between Stockton and Discovery Bay. A 2,000-foot section of a breakwater was causing an estimated 6,000 gallons of water per minute to be released through its base, the state said.
Emergency crews immediately worked to protect residential properties, Highway 4 and drinking water inlets by adding temporary protective barriers. The repair work was completed in January 2025, but a state emergency declaration was made in May 2025 allowing the Governor’s Office of Emergency Services to assist the county with additional work to shore up the levee.
Now, in the face of a “super” El Niño, flood risks from aging levees in and around Stockton could prove even more dire.
