Hot weather that’s melting a heavy winter snowfall and filling reservoirs has prompted the National Weather Service to issue a flood advisory for portions of the central San Joaquin Valley until Sunday.
The weather service said water releases at Friant Dam have been increased due to snow melt.
Locations along the San Joaquin River from Friant to Mendota are the most likely places to experience minor flooding, as river levels are expected to rise over the next several days.
Residents in nearby areas are urged to take precautions.
The Kings River has so much water in it that some low-lying areas below Pine Flat Dam have already flooded and the weather service issued an advisory for additional flooding through Monday.
The weather service said locations below Pine Flat Dam expected to experience additional flooding including Minkler, Reedley, Kingsburg and Grangeville.
The Fresno County Sheriff’s Office said it ordered people living in the rear of the Riverbend Mobile Home Park in Sanger to evacuate, affecting 12 homes and about 15 people. The front of the property remains under evacuation warning.
Deputies are also monitoring Kings River Road in Reedley where 10 homes are at risk and the Hauli Huvila campground and the Wildwood subdivision where about three dozen homes are near the river.
The American Red Cross has an evacuation shelter at Reedley High School.
Meanwhile, Firebaugh officials took the step of ordering the San Joaquin River closed to swimmers for at least two weeks.
Water flow is expected to reach 4,000 cubic feet per second (one cubic foot equals about seven gallons).
Ben Gallegos, acting city manager, said water on Friday was moving at about 2,500 cubic feet per second, and even that is too dangerous to allow people in the river despite the triple digit heat.
“There are some areas where the public can access the river right now and we’ve seen some families out there,” he said. “We want to make sure folks don’t go out there.”
In winter, water was running fast, flooding parks and rodeo grounds, but residents weren’t flocking to the river to swim then, Gallegos said.
“With temperatures so hot, it looks inviting,” he said. “The water is cold and moving fast, so it’s unsafe to be swimming in that river.”
Meanwhile in the Kings River area, concern is growing in the Tranquillity area where irrigation district employees are watching water channels around the clock, said Danny Wade, Tranquillity Irrigation District general manager.
Repairs were made earlier this year to boost channel capacity in anticipation of a heavy snowmelt.
The repairs restored the channel to 4,750 cubic feet per second, but it may not be enough if the flood releases from Pine Flat Dam keep increasing, Wade said.
Water from Pine Flat travels down the Kings River and flows north toward Tranquillity. It takes about five days.
“They are telling us the next three days are critical and if we can get past the next three days, we should be all right,” Wade said. “It’s hard to tell what will happen with snow melting and how fast it’s going to melt.”
Water is diverted at Crescent Weir in Kings County where the water flows north toward Tranquillity but it’s not supposed to exceed 4,750 cubic feet per second. If there’s more than that, the excess is supposed to be sent south to the Tulare Lake Basin.
As of mid-afternoon Friday, the amount of water flowing past Crescent Weir toward Tranquillity was 4,620 cubic feet per second.
The flood releases from Pine Flat increased late Thursday but stayed steady Friday.
It appears that inflows into Pine Flat Lake peaked Wednesday.
Water is expected to be let out of the lake, which was 99.4 percent full on Friday, at a furious rate through June, the King River Water Association said.
So far, water for irrigation – but no flood waters – has gone south toward the Tulare Lake Basin via the south fork of the lower Kings River, the association said.