Avista Corp., of Spokane, has selected Spokane-based Max J. Kuney Co. as the contractor for a planned $13.5 million upgrade and restoration of the south channel dam on the Post Falls Dam complex.
The work will include removing the original concrete facing and gate frames and adding new concrete, spillway gates, and hoists, says spokeswoman Debbie Simock, a spokeswoman for the energy company. Also, remote control equipment will be installed to replace equipment currently operated manually.
To perform the improvements, Kuney will construct a temporary structure, called a cofferdam, just upstream from the south channel dam to dewater the work area and provide a construction-crane platform, Simock says.
Work is expected to begin within a couple of weeks, as peak spring runoff subsides.
“Right now, water levels are receding,” Simock says. “But there’s still 113 percent of snowpack left in the higher elevations, so we know there will be a phase two,” of the spring runoff.
The 108-year old south channel dam is one of three dams in the hydroelectric complex on the Spokane River in Post Falls. The Post Falls Dam complex produces 18 megawatts of electricity—roughly enough energy to power 13,500 homes, Simock says. Avista upgraded the middle channel dam in 2012 and the north channel dam in 2012.
The complex also is used to help control the water levels of Lake Coeur d’Alene and parts of the Spokane, Coeur d’Alene, and St. Joes rivers during certain times of the year.
The upgrades will increase flexibility in responding to changing river flows and customer demand, Simock says.
Most of the work will be conducted with the Spokane River and Lake Coeur d’Alene at the full summer pool level, with minimal or no impacts on recreation, she says. Most of the construction work is scheduled to be completed by year-end, and final roadwork and landscaping will be completed in spring 2015.
Denver-based AECOM is the civil engineer on the project, and Avista is designing some of the electrical controls in-house.
The south channel project is one of several Spokane-area capital projects valued at $235 million that Avista will have in some stage of construction this year, the company has said.
In a separate project, Avista plans to construct an access point for a whitewater feature that kayakers have named the Trailer Park Wave, downstream from the dam.
Simock says Avista has allocated $1.2 million for the whitewater project, which includes the costs of acquiring 2.8 acres of land on the river and anticipated improvements.
The staging area will have six parking spots, a trail to the river, a couple of benches, and a toilet, she says.
“It’s really just for kayakers and tubers to put in,” Simock says.
Avista is preparing to put the whitewater project out to bid, Simock says. “Our hope is it will be constructed this year and maybe open by late fall or certainly by next year’s recreation season,” she says.