Working 217 feet above a riverbed in sub-zero weather, a team of workers pulled out a piece of history from the Williams Fork Dam in Grand County.
The important piece of the dam is a 5-ton steel gate that was removed as part of a $2.3 million preventative maintenance project at the Denver Water dam east of Kremmling, Colorado.
“This is the first time we’ve removed the gate since it was installed when the dam was raised in 1959,” said Nathan Smith, design project engineer at Denver Water. “It’s important that we maintain the moving parts in our dams so we don’t have problems that could compromise the operations and safety of the facilities.”
Sitting 120 feet below the top of the dam, this important piece of infrastructure slides up and down to channel water into the dam’s hydroelectric plant when needed.
“Over time, wear and tear occurs and corrosion forms on the gate, which can eat away at the steel,” Smith said. “We’re going to sandblast it to remove the corrosion, and then replace worn components and recoat it so it lasts another 60 years or more.”
The rubber seals on the gate also will be replaced to ensure a tight fit when its closed.
About the size of a single-car garage door, pulling out the gate was no small feat. The team first removed the 100-foot-long lifting mechanism, followed by the steel gate itself. Then, the crews used a crane to lift it off the dam and onto a truck where it was taken to Chariton, Iowa for refurbishing.
“It took about three days to remove the gate in sub-zero weather, but it came out without any problems,” said Ryan Rayfield, Williams Fork Dam supervisor.
Once refurbished, Denver Water and Gracon LLC workers will be back on top of the dam to reinstall the gate in March.
The Williams Fork maintenance project also includes a full tuneup of the dam’s 3.0 megawatt hydroelectric power turbine and generator that was installed in 1959.
“We’re going to disassemble the hydro unit, inspect it and replace or refurbish parts that are showing signs of wear and tear,” Rayfield said. “Keeping the hydro in good shape increases its efficiency for making power.”
Work on the hydropower unit is expected to begin in Fall 2018.
“Maintaining our infrastructure is year-round work at Denver Water,” Smith said. “We’re always evaluating our dams to make sure they’re safe and working properly.”