In the early summer of 1976 the Teton Dam in Idaho failed.
Sugar City, Rexburg and Wilford were flooded as water poured out of the dam at the rate of one million cubic feet per second. The disaster killed 11 people.
In respose the U.S. Bureau of Reclamation created the national Dam Safety program.
More than a decade later, in 1989, the Quail Creek Dike near Saint George failed.
“There were no fatalities, luckily,” said Teresa Wilhelmsen, state engineer and director of the Division of Water Rights. She delivered an update on statewide dam safety on Tuesday during a legislative interim meeting of the Natural Resources, Agriculture and Environmental Quality Appropriations Subcommittee.
But the failure at the Quail Creek Dike did “create and really propel” Utah’s State Dam Safety Program, Wilhelmsen said.
There are now roughly 6,500 dams on the state’s inventory and inspectors check more than 300 operational dams each year. “We spend quite a bit of the summer out in the field, inspecting these dams with the owners,” Wilhelmsen said
“We talk about adding infrastructure to the state and building additional,” Wilhelmsen said, “but I think it’s just as critical that we maintain the dams that we have in a safe condition because they provide a huge benefit.”
The Utah State Dam Safety program’s main focus is on high-hazard dams. A dam is classified as “high hazard” if its failure would likely lead to people dying, Wilhelmsen explained to legislators. That rating doesn’t have anything to do with the condition of the dam, but with the consequences. A dam is deemed “moderate hazard” if its failure would result in significant property loss but not death and “low hazard” would be some property damage.
There are 223 high-hazard dams in Utah and 101 of those dams need to be upgraded to meet minimum standards. Of those 101 dams, 24 are already in some stage of either construction or design. That leaves 81 high-hazard dams that aren’t yet up to the state’s standards.
In the meeting, Wilhelmsen and Candice Hasenyager, director of the Division of Water Resources told lawmakers that at current funding levels of about $3.8 million a year it could take about 120 years to update all the dams in the state. Although it might take even longer as more people move into areas near dams, pushing them into the “high hazard” category. Plus, inflation and evolving safety standards could make the repairs even more costly in the future.
“It is very sobering,” said the committee chair Sen. Scott D. Sandall, R-Tremonton.
On average it costs the state $4.5 million to upgrade one dam. Under Utah law, the state engineer cannot force a “mutual irrigation company or water users association” to upgrade their dam to meet minimum standards unless the Board of Water Resources offers to pay for 80% of the costs.
Federal and for-profit privately owned dams don’t qualify for the state’s grant funding program.
A national issue
Dam safety is a concern across the country — in 2022 the Associated Press found more than 2,200 high-hazard dams “in poor or unsatisfactory condition in the United States. The Association of State Dam Safety Officials estimated last year that it would require $24.04 billion to rehabilitate non-federal, high-hazard dams nationwide.
The development below dams is an added concern.
“When you’re the state engineer and you’re looking for a house the two top things on your criteria are: are you below a dam or below a canal?” Wilhelmsen said. “You don’t buy there. But people do. They live where they want to live.”