Work on Fresno Dam set to start

Representatives of Montana Fish, Wildlife and Parks and the U.S. Bureau of Reclamation held an open house meeting Wednesday to provide a fisheries update for Fresno Reservoir and information on the work about to start at Fresno Dam this month.

BOR Project Manager Steve Darlinton said NW Construction will be mobilizing April 17 to start on the project to address structural issues that could evolve into safety concerns long-term.

Darlinton said there are cracks forming in the dam but he wanted to make clear that there is no evidence that they pose an immediate danger.

He said BOR is concerned that as water levels change year on year, these cracks will get larger or be added to, which could lead to a failure somewhere down the road, but that potentiality is a ways away, so there is no immediate threat of failure.

He said the reason they haven't been letting water go over the spillway during good water years was because they didn't want to exacerbate the cracks in the dam, and once it is fixed they will go back to letting water go over the spillway.

He said the dam, since its construction in 1939, has experienced 7 to 10 feet of settlement, though he later clarified that they have taken steps to slow down that settlement and it has slowed significantly in the last two decades, leading one member of the audience to call the 7 to 10 feet figure misleading.

Darlinton said there will be no drawdown in the first year of construction, which will see them installing a water system that will help the dam function as normally as possible as they are working on it.

He said the tailwater fishing site will be closed for the duration of the project, but the north side will stay open.

In year two of the project, he said, they will need to reduce water levels in the reservoir as they dig into the dam, but there will be no change to pool levels below the spillway.

As for the road over the dam, it will need to be closed from Aug. 15 through December of 2024, which will probably be the biggest impact of the project.

After that, the dam road will be intermittently one-lane during the project.

However, after the project is done, he said, the road will be significantly widened, the dam having added 25 feet of width.

One audience member said he'd heard a rumor that they were considering putting a bladder in the dam, and Darlinton said they were considering it, having gained access to new funds because of the recent drought.

During the meeting, Havre Areas Fisheries Biologist Cody Nagel also gave an update on Fresno Reservoir's fish populations and habitat conditions as well as the FWP's 10-year plan for the fishery.

Nagel said the fishery is being managed for the purpose of producing 10- to 20-inch walleyes through habitat creation, stocking and maintaining healthy forage fish populations.

He said Fresno has been affected by extreme drought conditions that have persisted through the past few years, with water levels measuring 30 feet below full pool for the last three years.

However, he said, despite these troubles, the last few years have provided an opportunity for shoreline vegetation to grow uninterrupted, and this, aided by FWP creating habitats of its own with the help of Fresno Chapter of Walleyes Unlimited and the City of Havre, sets the stage for a strong comeback for the fish populations.

As for 2022, Nagel said, FWP has been analyzing the data they've collected on the forage fish populations of yellow perch, black crappie and spottail shiners, which are the big three for Fresno.

He said the ideal catch for nearshore forage fish is between 100 and 200 forage species fish per net, and they averaged 134 this year, though the three-year average is still under what they hoped, coming in at 94 fish per net.

He said they saw 0.64 adult yellow perch last year, well under the goal of 2 to 4, a goal they've only met three times in the last 10 years.

Adult black crappie was 0.18 per net, well under the 1 to 2 goal, which they've only seen once in the past 10 years.

Northern Pike only saw 1.27 per net last year compared to the goal of 2 to 4, but the three-year average is still at 2.26.

Nagel also went over the history of stocking in the reservoir, saying they planted 34,000 fish in 2021 since their 10-year plan was implemented, and just over 50,000 last year.

In 2021, he said, they saw the lowest relative abundance of walleyes in 15 years, with 12.36 per net compared to the three-year average of 19, and their goal of 18 to 21.

Despite these grim numbers, he said, they've observed a healthy spread of fish ages, including a high number of spawning-age fish and that combined with stocking could lead to a big comeback.

"Everything is there for things to rebound," Nagel said.

In 2023, he said, they are planning to stock 75,000 walleye fingerlings, continue their habitat enhancement projects with the help of Walleyes Unlimited and keep up their population monitoring.

When asked if the Fresno Dam Project would affect stocking rates or fish management, he said no.

When asked about whether the snowpack will help fill the reservoir this year, Darlinton said they are predicting it will not, since snowpack at the St. Mary Diversion is actually lower than normal this year, compared to the snowpack downstream of Fresno being much higher than average.

Darlinton said the upside is that this increased snowpack beyond Fresno should help meet local irrigation needs and allow more water saving for everyone upstream.