Danger ahead: It’s getting hotter and rivers look refreshing. What to know before you dive in

Rivers in the central San Joaquin Valley are beginning to rise as temperatures heat up and snow begins to melt, sending menacing currents downstream.

Authorities are warning the public against leaping into rivers with strong or high currents after some waterways have already showed flood potential and after a 16-year-old fell into the Tule River earlier this month.

Another person was rescued Thursday from the St. Johns River in Visalia after becoming stuck in a low-head dam.

The larger rivers are being monitored as water levels creep up and pose flood risks.

The San Joaquin River, brim-full with releases from Friant Dam of Millerton Lake water, Friday May 31, 2019. JOHN WALKER jwalker@fresnobee.com

San Joaquin River

The San Joaquin River was flowing at about 6,000 cubic-feet-per-second from Millerton Dam on Friday, according to the Army Corps of Engineers.

The San Joaquin River Parkway and Conservation Trust issued a friendly warning to visitors, saying “The San Joaquin River may look like a place to cool off when the temperature is high, but it is not safe for swimming under current conditions.”

Fresno County Sheriff’s Office spokesman Tony Botti said the San Joaquin River, like the Kings River, is being monitored but no significant flood threats or potential for closures have arisen.

At Lost Lake north of Fresno, conditions are normal, Botti said: The annual snow melt typically causes the river to flood some low-lying picnic areas and parking lots.

“Any time people and property are threatened, that’s when we’ll work to adjust things,” Botti said. For now, the sheriff’s office is monitoring the rivers as more snow melts.

A half-submerged picnic table sits in the San Joaquin River at Lost Lake Park, Friday May 31, 2019. JOHN WALKER jwalker@fresnobee.com

Kings River

The Tulare County Sheriff’s Office announced a closure for the lower portion of the Kings River after threatening levels were seen Thursday. Boating and swimming along the lower part of the river is not allowed during the closure and deputies will enforce it, the sheriff’s office said.

The Army Corps of Engineers has begun releasing water from several dams for flood relief along with the usual irrigation purposes. As of Friday morning, the Kings River was getting 9,188 cubic feet-per-second discharge of water from Pine Flat Dam.

In the Fresno County portion of the Kings River, there are no blanket restrictions. But the City of Reedley issued a closure for Reedley Beach on Friday after water began to rise there.

Botti said the Fresno sheriff’s office would consider closing full access to the Kings River if it reaches a water flow of 10,000 cubic-feet-per-second — which could come next week.

“Due to information obtained from the U.S. Army Corps of Engineers, Sheriff Margaret Mims anticipates a possible closure next week to this portion of the Kings River,” the sheriff’s department said in a news release sent Friday afternoon. “This would apply to all recreational users, such as boaters, kayakers, tubers, swimmers, etc. Enacting a closure would be a difficult decision, but one that must be made in the best interest of public safety.”

Merced River

The Merced River, which rushes through and out of Yosemite Valley, was flowing at about 4,000 cubic-feet-per-second, which was a normal flow for this time of the year, according to Mike Jensen from the Merced Irrigation District.

He said the river could flow to as high as 6,000 cubic-feet-per-second. Once high flows are seen, Jensen said the irrigation district collaborates with county officials to determine what precautions are needed.

Mike North, Merced County spokesman, said the lower part of Hagaman Park is closed due to flooding, but the upper part of the park is open. He said flooding so far has not been a concern in other areas.

Signs along the river caution visitors against trusting the water at this time.

“I don’t think people realize how fast moving and how cold that water is,” North said.

There were no reports of flood threats in Yosemite National Park, according to officials there, but they did warn that rivers and creeks in the park are expected to rise over the next week and will be running high.

“As beautiful as they may look, they are also deadly … Stay back from swiftly moving water and be aware that even dry rocks are slick,” Yosemite officials said Friday. “Do not climb over railings to get closer to water. The majority of people who are rescued or recovered from the river never intended to go in.”

Tule River

The Tule River in Tulare County and Sequoia National Forest was closed May 20 due to unsafe conditions.

“If shutting down access to a public waterway saves just one life, it is worth any slight inconvenience that it might cause,” Sheriff Mike Boudreaux said in the news release announcing the closure.

A 16-year-old boy went missing May 12 after suddenly going under the water in the Tule and never coming back up. He wast last seen in the area between Springville and Camp Nelson above Coffee Camp.

Friday morning records showed the river was flowing at 307 cubic-feet-per-second from Success Dam.

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Cresencio Rodriguez-Delgado is a general assignment reporter at The Fresno Bee. He grew up in Porterville and has a bachelor’s degree in print journalism from Fresno State. He is a former student editor at the Fresno State and Fresno City College newspapers. His hobbies include reading, sleeping, running and taking care of his dog.