Concerns on the rise about “danger stage” for the San Joaquin River at Vernalis
The sunny skies on Saturday did not signal an end to concerns about potential flooding on rivers in the Northern San Joaquin Valley.
The situation seemed to improve for Stanislaus County residents but became more dicey for folks in southern San Joaquin County.
A high river flow drew attention to the San Joaquin River at Vernalis, which was slightly above the 29-foot flood stage level at 4 p.m. Friday.
Saturday, the San Joaquin at Vernalis slightly surpassed the “danger stage” of 29.5, hitting 29.6 feet by mid-morning. It’s a term used by state officials when flow is greater than the design capacity of a flood control system and failure could result in significant damage to homes and other property.
In other words, the levees near South Airport Way and the San Joaquin, south of Manteca, are not designed to handle more flow than that.
Scott Rowe, a meteorologist for the National Weather Service in Sacramento, said the stretch of river is projected to hover around 29.5 to 29.6 feet for the next four days. That projection takes into account current water releases from dams and reservoirs, some rain that’s expected Saturday night and Sunday and the beginnings of a bigger storm next week.
“We’re talking about a tenth of a foot just above the danger stage for the next five days,” Rowe said. “It takes into account precipitation through Wednesday.”
Beyond Wednesday, there’s no prediction for the river level.
The river location is where levees failed during the 1997 floods, inundating the farms and dairies south of Manteca and causing evacuations and tremendous damage.
The San Joaquin would need to rise another three feet at Vernalis to reach what’s considered the moderate flood level. Local districts that monitor the levees have seen worse. The record level is 34.9 feet, according to the Weather Service.
“On our side we are good,” said Stanislaus County Sheriff’s Deputy Raj Singh. “What we have been told is that the (San Joaquin at Vernalis) is still flowing, so that’s good for us. It keeps us below the flood stage level.”
Singh said there are no plans to change evacuation orders or warnings on portions of the San Joaquin River near Newman and Patterson. The river level in Stanislaus County was staying flat. It was four to five feet below flood stage in Newman.
“Our forecast does not show it going up,” Singh said.
Turlock Irrigation District was releasing water from Don Pedro Reservoir on the Tuolumne River, some 38 miles east of Modesto, ahead of the storm that’s expected next week. The releases ensure there is space in the reservoir for flood control purposes.
On Saturday, the Tuolumne was still running about half of foot below the minor flood stage of 55 feet in Modesto. The river is expected to remain at that level through Tuesday.
Bee staff writer Marijke Rowland contributed to this report.
