Gov. Gary Herbert joined those urging caution and sounding alarm at the danger the record flows could pose.
"Waterways are always risky business, but with these turbulent flows ... it's becoming extremely treacherous, and the next couple of weeks are going to be very difficult for us," Herbert said.
In normal years, rescue workers expect a 10-day period of swift-flowing water, but this year it will last at least a month, said Utah County sheriff's Lt. Yvette Rice, likely peaking the third week in June.
The dangerous water claimed another victim Wednesday after rescuers pulled 8-year-old Jayson Robert Corporon from the American Fork River.
Jayson was with his parents and 3-year-old sibling at a day site just below Tibble Fork Reservoir when he fell into the river. His mother jumped in to save him but had to be rescued herself about 100 yards away.
"The water was very cold the water was moving very violently," Rice said. "She got banged up pretty badly."
Jayson was last seen floating under a bridge near another day site. Without cellular phone service, people drove 40 minutes down American Fork Canyon to the Timpanogos Cave Visitor Center to call police. Searchers found Jayson about 9:30 p.m. near the Roadhouse day use area, about two miles from the reservoir. He was taken to a hospital, where he died.
His mother was taken to a hospital and treated for hypothermia she suffered in the 46-degree water.
The frigid snowmelt water across the state is especially dangerous, McInerney said in high-30-degree water, the body shuts down within two minutes.
Police don't know exactly what Jayson was doing when he fell, but Rice warned the fast water has eroded the riverbanks, turning once-solid surfaces into potential danger zones.
"If a section has been eroded out underneath and you get enough weight on top, that can just come crashing down," Rice said. "The next thing you know, you're in the water."
She recommended parents put children in life jackets anytime they get close to open water.
The governor expressed his sympathy to those close to the recent drowning victims.
"This is a difficult time for them. As a father and grandfather, I can only imagine the anguish these people are going through as these tragedies occur," Herbert said.
Others who died in Utah water this spring
Vincent Larsen • Two-year-old Vincent Larsen died on May 29 after he fell into Starvation Creek.
Danny Ellison • On Tuesday, 13-year-old Danny Ellison died after being pulled Saturday from the Provo River.
Donaven Albert Lopez • On Wednesday, the family of 2-year-old Donaven Albert Lopez removed him from life support a day after he passed through a hole in a park fence and into a canal in Riverton.
Shirley Palmer • On May 31, 73-year-old Shirley Palmer drowned when her inflatable kayak flipped on the Green River.