BUHL — Floods have overwhelmed the Magic Valley in one of the largest wintertime natural disasters in generations, forcing emergency evacuations, closing schools and prompting desperate pleas for volunteers to help stave off rising water.

Warm weather is melting a historic snowfall. The thaw that began earlier this week triggered widespread crisis Thursday. A canal was partially breached overnight near Castleford and Buhl, displacing several families. The American Red Cross opened an emergency shelter at Amazing Grace Fellowship, 1601 Eastland Drive N.

Districts in Filer, Buhl and Minidoka County closed schools in the middle of the day. A car that bypassed a police barricade in Twin Falls County was swept away by violent floodwaters west of Buhl. Segments of some roadways simply disappeared, ripped apart by rushing water.

Authorities reported no deaths or serious injuries but pleaded with motorists to stay off water-covered roads.

“Becoming submerged is a danger,” Cassia County Undersheriff George Warrell said. “If it looks deep, don’t enter it, especially if you have a small vehicle.”

Aerial photographs showed floodwaters stretching for miles across Cassia County. A 36-mile stretch of Interstate 86 that had been closed since Monday reopened, but authorities worried floodwaters could soon threaten Interstate 84, the primary stretch of interstate highway through the Magic Valley.

In Twin Falls County, officials told people to avoid the entire western portion of the county, where roads washed away and at least eight homes flooded. Inspectors rushed to canals, roadways and bridges threatened by the rising water.

Sheriff’s deputies went door to door in Twin Falls County after the canals flooded. Emergency crews were overwhelmed, and authorities warned residents they were mostly on their own.

"The county received no sandbags whatsoever from the state of Idaho," Twin Falls County Office of Emergency Management Coordinator Jackie Frey said. "The citizens need to prepare their own homes and do their own mitigation efforts."

Sandbags were in short supply across the valley. Volunteers ran out of bags in Malta and ordered an emergency supply from a distributor in California; they were expected to arrive Friday.

Runoff, ice in canals caused flooding

Carrie Myers' husband was up half the night diverting floodwater from their Filer home, but after two hours of rest, the front yard was flooded and water was spilling into their basement.

The water wasn’t coming from the overflowing irrigation canals but directly off the field in back of her house. And there was no stopping it.

“I really don’t think it was preventable,” she said.

The 6 inches in her family’s basement was about half what it had a couple of weeks prior during the last flood. But despite stocking up on sandbags and digging channels for the water, it still did damage.

“The basement isn’t bad, but the front of the house is sinking,” Myers said as she stood outside her home wearing tall rubber boots.

Other families were evacuated from the Buhl and Castleford area. Overflowing in numerous places along the Lowline Canal — and a partial breach in the Highline Canal — resulted from ice buildup and rapid melting, canal company staff said.

Some homes escaped the flooding, but one farm (and an unknown number of other homes) wasn’t so lucky.

“We feel terrible about places that have been flooded,” Twin Falls Canal Co. General Manager Brian Olmstead said. “This wasn’t one drop of our water. … Everything above the canals ended up in the canals.”

By the afternoon, the Lowline Canal and the Cedar Draw drainage were far below where they’d been the night before, but water from various fields and Deep Creek continued to flow across county roads.

Unusual weather

It was around 6 p.m. Wednesday evening when Olmstead got the call from the canal company’s water master: The gauges measuring flow at the Cedar Draw were rising rapidly.

“He said: ‘We’re not going to be able to confine it,’” Olmstead recalled. “’It’s too much.’”

This was the most water Maintenance Supervisor Doug Howard had seen in more than 30 years with the Twin Falls Canal Co.

Rising temperatures rapidly melted snow in higher places, and water coming of the Salmon Falls canals inadvertently flooded the other canals.

Additionally, extra water flow in the Highline and Lowline canals broke off large chunks of ice along the bottom, formed during freezing weather earlier. The ice floated to the top and created dams in multiple places. The Highline Canal had experienced a partial breach early Thursday morning at its tail end, flooding one farm.

“We just need to get the water level down,” Howard said as he surveyed four excavators plucking up ice from the cold water of the Lowline in the afternoon. “We tried to evacuate everybody within a 2-to-3 mile radius this morning.”

He’d already planned to bring in four more excavators from contractors, adding to the 11 machines that were already hard at work.

“We cleared ice," Olmstead said, "but it keeps on coming.” 

Crews aimed to push flooding farther downstream, having already diverted the water away from highways and towns. It was mostly the last 4 to 6 miles of canals that were affected, Olmstead said.

Crews used spillways like Cedar Draw, which “looked like Niagara Falls coming in last night. Sounded like it, too,” Olmstead said.

While spilling as much as safely possible into Cottonwood, Cedar Draw, Rock Creek and Deep Creek, the Lowline still flooded its banks. Deep Creek also flooded, inundated with about 800 cubic feet per second of water from the Highline Canal — and another 600 cfs from the Lowline. That’s about four times what it usually receives.

“This is probably the biggest flood Deep Creek’s ever had,” Olmstead said, recalling another major flood back in 1979.

A section of road at 3500 North and 1900 East was destroyed by the water, and a bridge at 3400 North was still under water. The Twin Falls Canal Co. had run completely out of “Water Over Road” signs, Olmstead said.

The canal company could not have used laterals to lighten the load on the main canals, Olmstead explained, because the laterals are filled with snow. It is too hard for crews to maintain the small channels in the winter, and clearing them would only have pushed the flooding to less preferable areas, he said.

Emergency response

After being notified of the potential for flooding, residents in the Buhl and Castleford area sprang into action, preparing their homes with sandbags, Twin Falls County Office of Emergency Management Coordinator Jackie Frey said.

The American Red Cross opened the shelter for displaced families shortly after midnight.

“We have cots and blankets,” said volunteer Nicole Stevenson. “If we do have a lot of people, Salvation Army will usually come in and feed everybody.”

Water and fruit for immediate needs was available. Each of the two shelter trailers was equipped for 50 shelter residents, said Red Cross Disaster Action Team coordinator Diana Ochsner.

As of 10:30 a.m. Thursday, no residents had used the shelter. They opted instead to stay with families or protect their homes, Frey said.

The Twin Falls Canal Co., Twin Falls Highway District and Twin Falls County Sheriff's Office worked to mitigate damage to life and property, but the National Weather Service has warned of an upcoming rainstorm that may affect the South Hills drainage area. McMillen Creek, Rock Creek and the Perrine Coulee on College of Southern Idaho's campus are being monitored, Frey said.

Should a problem occur, an emergency system will send warnings to those in affected areas.

"Mother Nature has definitely come after us," Frey said. “We never expected to see the amount of moisture we received.”

Outbrain