The first phase of the Logan River Third Dam construction is going on despite rain, snow, sleet and even sub-zero temperatures. Workers are digging with a track hoe, tying steel, pouring concrete and moving forward as planned to upgrade the old structure in Logan Canyon.
Just about the time the weather warms up and workers can shed their thick winter clothes and dig into their work, they will have to leave the job site and find something else to do.
Construction will be halted between June 1 and August 31, during the best working conditions in the canyon, due to the nesting habits of the endangered Yellow-billed Cuckoo bird.
Although the migratory bird is common in the eastern part of the country, they are rare in the west. The largest part of their western habitat starts roughly at Logan Canyon and runs to just north of the Bear Lake. There are hundreds of miles of suitable habitat. During spring and summer, the birds spend their winters in South and Central America.
Mark Montgomery, director of Logan Light and Power, said he hasn’t talked to anyone who has seen any of the yellow birds in the canyon. He knows of some spotted near Strawberry Reservoir.
The birds are really shy and stay well hidden. They feed on large caterpillars.
When crews get back to work after the break, they will try to finish the first $6.2 million phase of the project.
The project will include removing the silt and sediment backed up behind the dam. They also plan to refurbish the turbines if they can.
“The hydroelectric generators are kind of historical relics,” said Montgomery. “The original structure was built in the early 1900’s. I think it was upgraded to its current state around 1920 and hasn’t had anything done to it since then.”
“Stantec has a photo taken around 1904 of some men standing on the dam,” Montgomery said. ”I think it was built with rock boulders covered with concrete back then.”
Some of the original wood from first dam can still be found on the site. The gatehouse at second dam is also historic, built at the same time as the dam.
Greg Clark, an engineer for Stantec – an international engineering firm contracted by the city to do the project – said the project is being overseen by a host of government agencies.
Logan City and the engineering firms making upgrades to the dam must work though Federal Energy Regulatory Commission, U.S. Forest Service, Army Corp of Engineers, Utah Department of Transportation, Department of Transportation, Utah Dam Safety, U.S. Fish and Wildlife, Utah Division of Wildlife Resources, Utah Division of Water Resources and the State Historical Preservation Office.
Even though the dam was not due to be serviced for another few years, Clark said the city decided to be proactive and make some needed upgrades.
“If you pick up some of the cement it crumbles in your hands,” said JUB Engineer Paul Willardson, who is working with Clark on the project. “We are upgrading most of the cement work.”
He explained Third Dam is a diversion dam used to take water from the river and push into a 78 inch pipe that pushes water to the turbines at the second dam’s generating plant.
Reconstruction of third dam is expected to go through the 2019-20 construction season.