Reclamation begins planning process for modifying Fresno Dam

 

March 20, 2019

Havre Daily News/Ryan Berry

A man fishes Tuesday alongside his dog at the base of Fresno Dam about 10 miles west of Havre.

Bureau of Reclamation is looking into Options for plans to modify Fresno Dam on which the bureau intends to start construction within the next two to three years as part of its Dam Safety Program.

"Reclamation is currently evaluating alternatives to modify Fresno Dam," Reclamation Montana Area Manager Steve Davies said. "It's not because of damage that is there. The dam is fine, it's safe, we are under normal operations. But as part of our dam safety program, we've determined that, because of the age of the facility, the construction of the facility, we needed to make some modifications to bring it up to standards."

Fresno Dam is part of the Milk River Project, he said, which serves communities across the Hi-Line and provides water to irrigators from Fresno Reservoir to Glasgow.

He said that the Fresno Dam project is still in the early stages of planning, and bureau has not identified what alternative it will use.

"We may have that sometime early summer or so," he said.

Reclamation is not only evaluating the cost, but also whether the modification made would achieve the appropriate risk reduction, Davies said. Fresno Dam is no longer in accordance with Reclamation's Dam Safety Program, he said, which has specific guidelines and risk standards.


Davies said that the alternatives depend on the dam. Every dam is different and faces different issues, dependent on the particulars of the dam, he said. He added that modifications are done to address specific issues, such as seismic issues, seepage, flooding or maintaining normal operations.

"There is potential that these kinds of projects could impact (irrigators), so we involve them in that discussion," he said. "Right now, though, it is too early."

Jennifer Patrick, project manager for Milk River Joint Board of Control that comprises representatives of irrigation districts in the Milk River Project, said that the safety of the dam is the main issue Reclamation is evaluating.

She added that Fresno Dam is only one tiny portion of the Milk River Project, she said. She said St. Mary Diversion, which provides much of the water in the Milk River each year, is in a state of catastrophic failure. If St. Mary's fails, she said, Fresno is not even a conversation.

"We're fixing the middle when we should be fixing the beginning," she said.

She added that she understands that the safety of Fresno Dam is important. She said Reclamation doesn't want anyone to be impacted by a dam failure.

"You cannot put a price tag on someone's life, and that is what they are looking at right now," she said.

Davies said it is to early to speculate on what the effects would be during the construction period of the modification, including whether the dam will be able to operate normally or if Reclamation will have to empty the reservoir, he said. He said that Reclamation will have to perform an environmental impact study, on the impact of the modification. He said that the evaluations will need to be completed before Reclamation is able to move forward with the design.


He added that construction is still approximately two to three years away. Reclamation is trying to keep an aggressive schedule in order to stay within the timeline, he added.

Davies said that under the Dam Safety Act, 85 percent of the cost is covered by the federal government and the other 15 percent covered by the beneficiaries.

Patrick said that, as the project sits currently, the modification's total cost could be more than $50 million. Under the Joint Board of Control, 110,000 acres of irrigated land is in the Milk River Project, she said. If the total cost of the alternative used for Fresno Dam resulted in $50 million, she said, the stakeholders in the Milk River Project would have to pay $68.18 per acre of land.

"It's kind of one of those tough pills to swallow," she said, "that it's so expensive, considering what they built the dam for in the first place."

The Milk River Project, an irrigation project which includes Fresno and Nelson reservoirs, was one of the first projects authorized for the Bureau of Reclamation after it was created in 1902.


Patrick said that the stakeholders would possibly have to request a federal loan in order to pay the initial cost.

Davies said that in Montana, Reclamation has already completed several of similar projects.

Following national guidelines for dam safety, he said, Reclamation has successfully modified Willow Creek, Clark Canyon and Helena Valley dams and has also recently finished modifications on Nelson Dykes.

Most of these were constructed in the early 1900s and 1910s, he said. He added that the infrastructure may still be able to perform but "we build dams differently today."

After the modifications on these dams they have excellent performance and can function safely for the years to come, he said. Davies said that in the far future, Reclamation may need to do these modifications again, although Reclamation does take the future into account when planning.

Davies said that the main reason for the modification of the Fresno Dam is the age of the infrastructure. When the dam was originally constructed in the 1930s, he said, it was built on compressible materials - soil - with a lot of settlling happening after it was built. The dam sank approximately 10 feet within a decade of construction, he said, and Reclamation needed to add material in order to get the dam to the appropriate height.

The dam, as it was constructed, is not conducive to defending itself from seepage, he said, adding that Reclamation has not found any signs of seepage currently. But part of the Dam Safety Program, Reclamation has to go through and regularly evaluate the construction, operation and safety of all the dams.

The way it was built also does not meet modern safety standards, he said. The dam is a single-zone structure, a homogeneous dam, built with a single type of material. Current-day dams use multi-zoned structures so they can more readily handle seepage and prevent seepage.

"It's really updating it to today's state-of-the-art design standards," he said.

For now, he said, Fresno Dam is still operating at full capacity.

"We aren't operating any differently," he said. "We are allowing the facility to fill and operate as it was originally constructed with no restrictions."

Havre Daily News/Ryan Berry

Wear on the exterior concrete of Fresno Dam is visible Tuesday.

 

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