In 2015, the Boise River ran dry for nearly seven hours. The cause was a power outage at the Barber Dam, which caused the low-flowing winter waters of the river to build up behind the dam without spilling over. The fix was relatively quick, but the problem of river levels dropping due to power outages at Barber Dam has persisted.
"The river, it is probably the finest urban trout fishery in the country," said Joe Kozfkay, a Regional Fisheries Manager for Idaho Fish and Game. "You're basically risking one of the best things about Boise."
In the most recent outage at the dam, which happened in mid-October, the river level was reduced to about one-fifth of its normal flow. This poses a risk to the fish in the river, which is not only a major community asset, but an economic asset too, Kozfkay said.
Which entity is responsible and what the potential solutions are is a complicated issue. The dam is owned by Ada County, but operated by Enel Green Power, with which the county contracts. The most recent outage was caused by a power grid failure. Notably, the dam is due for relicensing by 2023, which could be denied by the Federal Energy Regulatory Committee if the dam is determined to be harmful to the health of the river or fails to meet FERC standards.
"[Fish] can get stranded in these shallow pools," he said. "It sort of hurts the habitat and the food for these trout populations."
When the trout are stranded in the shallow pools along the river, they can suffocate if left for too long. Even when the river is restored, the availability of food can be an issue for the trout and other fish in the river.
"The trout fishery has a huge constituent group," Kozfkay said. "There's tons of users... it's a truly important resource."
The health of the river is not Kozfkay's only concern, but that it's a consistent problem and it doesn't seem that anyone is attempting to fix it.
"It happened again, it's continuing to happen, and it's not really being fixed," he said.
The risk of dewaterting the river is especially high when the outages happen at low-flow periods, as happened years ago. When that happened, Enel Green Power was forced to pay a settlement, which raised awareness of the issue, but the solution proved to be impermanent, Kozfkay said.
"Barber Dam is currently in the process of going through relicensing," Ada County Communications Manager Elizabeth Duncan wrote in a statement. "As part of relicensing, there will be an analysis of all water users who are currently taking water from the Boise River between Barber Dam and Glenwood Bridge (the measuring station) and all users' cumulative impacts on Boise River flows. In addition, engineering options and designs are being evaluated."
One step the county has taken is requiring the company to staff at least one person to operate the dam at all times. In the case that a power outage happens overnight, mitigation efforts can begin immediately.
The cause of the mid-October outage was an Idaho Power transformer that exploded, sending a surge of energy to the equipment connected to it. This caused the turbines of the damn to stop spinning, slowing the river's flow until it began to spill over the top, Duncan wrote.
Prior to the mid-October outage, the next most recent outage at the dam was just two months prior, on Aug. 2, prompting the Idaho Department of Water Resources to fine Ada County $50,000.
"Enel Green Power's standard operating procedures for this type of incident were properly followed: A technician was automatically notified of the disruption and responded immediately to restore function to the plant. Sixty-one minutes later, the plant was re-synchronized to the power grid," wrote an Enel Green Power representative in a statement.
Despite criticism, the company maintains that it and the county are following the proper procedures when handling the recent outages. Additionally, it noted that power grid disruptions are not within the company's control.
"Barber Dam operating procedures are designed to prioritize the safe and responsible flow of water in the Boise River above any power generation operations. Water continued to flow over the dam throughout the disruption, and the flow of the river was never cut off," the statement read.