SALT LAKE CITY — Workers scrambled to shore up a rural Utah dam after a 60-foot crack sent water into a creek and endangered the 1,800 residents of a downstream town.
State and local leaders do not believe the Panguitch Lake Dam is in immediate danger of breaking open, but have told residents to be prepared to evacuate if conditions worsen. Emergency management officials distributed a list of evacuation procedures to concerned residents at a town meeting Wednesday evening aimed at easing the panic.
“I can’t say the emergency has been completely averted, but I am very encouraged by the progress we have made today,” Everett Taylor, assistant state engineer for dam safety with the Utah Division of Water Rights, told city residents in southern Utah.
Lowering the reservoir below the affected area will take several days, he said. About 2 feet (61 centimeters) of water stood over the crack Wednesday evening, and workers had covered nearly 45 feet (14 meters) of the crack with boulders.
An ice sheet on the reservoir had pressed against the dam, causing the top to crack and topple downstream as water flowed through the opening, Taylor explained. His staff was able to relieve some of the pressure on the dam by making large cuts in the ice sheet. The ice has now cleared and the top of the dam has tilted back, he said.
Local officials discovered the crack in the upper portion of the dam during an inspection Monday evening, and state officials announced it to the public Tuesday. The state has named it a Level 2 breach risk – a designation in the middle of the three-tiered scale that means there is potential for dam failure.
If a breach occurs, state and local law enforcement agencies will work with the Red Cross to evacuate Panguitch, which is about 10 miles downstream from the dam. Another small town, Circleville, is further downstream and has a lower flood risk.
Sergeant Jacob Cox of the Utah Highway Patrol, who is tasked with preparing the city for an evacuation, told residents Wednesday that they needed enough time to gather their belongings and evacuate safely.
“This can be done in an orderly manner,” he said. “If the report comes that the dam has broken or breached, we have time. The estimate is about two hours before the water will really flood the city.”
In the event of an evacuation, sirens will sound and officers will go door to door to make sure everyone has cleared the area, Garfield County Sheriff Eric Houston said. A nearby chapel and a high school will serve as emergency shelters.
Water is released at a rate of almost 6.5 cubic meters per second to suck down the reservoir below the crack. Large stones are brought in and placed on the downstream side of the dam to support the wall. No rain is forecast until Saturday.
“We’re going to continue to focus on pulling down the reservoir, making sure that the ice… we keep that off the dam, and continuing to shore up or support this downstream side,” Taylor told The Associated Press.
The dam was built in the late 1800s, but the upper section that burst was added to the top of the dam in the 1930s and 1940s. There were no previous concerns about its structural integrity, and the crack came as a surprise, Taylor said.
Panguitch Mayor Kim Soper urged residents to stay away from the creek that collects the reservoir’s runoff, warning that water levels are much higher than normal and pose a danger to children.
He was shocked when he remembered standing in the same gymnasium in 2017 preparing evacuation plans when a wildfire devastated southern Utah.
“We got through this, and we will get through this,” Soper assured his community. “It’s just another emergency.”
___
Peterson reported from Denver.
___
The Associated Press receives support from the Walton Family Foundation for reporting on water and environmental policy. The AP is solely responsible for all content. For all of AP’s environmental coverage, visit https://apnews.com/hub/climate-and-environment