EMMETT, Idaho — Construction of a new hydroelectric generating unit that could help keep power rates stable for several irrigation districts in southwest Idaho has been delayed.
The Bureau of Reclamation’s most recent estimated cost analysis of the project at Black Canyon Diversion Dam indicates its price may exceed its financial benefit, bureau project manager Chris Vick said.
The bureau has hired an independent engineering firm to do its own cost-benefit analysis, a process that will delay the start of the project at least four months from its projected spring 2015 date.
The bureau hasn’t released the estimated cost of the project because it hasn’t gone out to bid. The recent estimate is based on the bureau’s own projections
Vick said the estimated cost of the project, which is being financed mostly by Bonneville Power Administration, increased as the bureau refined its design.
“The cost now exceeds the benefit,” he said.
Vick said the independent cost estimate should be completed by mid to late September.
If it indicates the cost of the project is justifiable, “we’ll meet with Bonneville Power to see if they want to move forward,” he added.
The proposed 12.5 megawatt hydroelectric unit would significantly increase the capacity of the two existing 5 megawatt units at the dam, which is located on the Payette River near Emmett.
If the project does move forward, the power produced by the new unit would be integrated into the grid to serve 10 irrigation districts in southern Idaho and eastern Oregon.
There are about 140,000 acres of irrigated land below the dam and irrigators hope the additional power would postpone the need to raise rates, said Ron Shurtleff, watermaster of the Payette River system.
“If it helps postpone any major increase in rates, that would be the biggest benefit for irrigators,” he said.
When the project was first announced, irrigators’ biggest concern was that it could result in irrigation water being diverted for power generation, said Jim Stanley, chairman of the Emmett Irrigation District.
Stanley said he was assured by Bureau of Reclamation officials that wouldn’t happen but he still thinks about it.
“They told me not to sweat it. Well, when you start talking water, I start sweating,” he said. “I dang sure want them to understand that the dam was put in for irrigation first and then comes power.”
Vick said the project will not result in any change to irrigation water delivery.
While construction of the new hydroelectric generating unit is on hold, some upgrades to the 90-year-old dam will proceed.
Vick wouldn’t guesstimate how the new hydro unit might impact rates, but he did say that together with the upgrades, it would make the unit more efficient and operations and maintenance costs are factored into rates.
“We do know that over the long-term, it will be a more efficient system with less operation and maintenance costs,” he said.