Sacramento County advised residents in the Tyler Island area south of Walnut Grove to evacuate Monday due to a compromised levee.
About 20 homes are in the area, said Sacramento County Water Resources spokesman Matt Robinson. Tyler Island is protected by a ring levee.
The county expected imminent failure of the North Fork Mokelumne River levee, the National Weather Service warned early in the afternoon. Robinson said there was some disintegration on the land side of the levee but no water has gotten through. Workers are piling rocks at the weakened point to shore it up, he said.
The California Conservation Corps redirected 45 corps members from a shelter at Cal Expo to Tyler Island, where they’re expected to help try to prevent flooding for the next few days, according to CCC spokeswoman Susanne Levitsky.
The evacuation is unrelated to concerns about the Oroville Dam emergency spillway that has forced evacuations in cities along the Feather River.
A notice went out at 10:30 a.m. to the Tyler Island residents. About an hour later, Robinson said, the county notified Walnut Grove residents of the issue, but did not ask them to evacuate because the small Delta town is protected by a secondary levee.
County Supervisor Don Nottoli, who represents the area, said it’s “pretty sparsely populated” and there isn’t a lot of livestock. Part of the area is farmed and part is industrial, he said, and a number of homes are elevated to avoid floodwaters.
“A lot of those folks are self-sufficient,” Nottoli said. He expected some residents who are part of the reclamation district will help fight flooding.
An evacuation notice remained in place for the Point Pleasant area on Monday. An evacuation and shelter-in-place notice for Wilton was lifted over the weekend, though some homes remain surrounded by water, Robinson said.
On Saturday, crews lowered a portion of the ring levee on the McCormack-Williamson Tract north of Tyler Island to allow for controlled flooding. Officials said Sunday the tract appeared partially full.
Officials were concerned about a potential “flood pulse” bursting the McCormack-Williamson levee and sending a torrent of water downstream that would damage neighboring Staten and Tyler Islands, as happened in the floods of 1997.
Nottoli, who has represented the area since 1994, said this winter’s floods are the worst south Sacramento County has seen since 1997.
This is a breaking news story. Please check back for updates.