Concrete crews at Minidoka Dam have worked tirelessly since mid-May to place two to four million pounds of concrete into the spillway foundation each week.
In November 2011, the $21.3 million replacement spillway construction project began. The century-old Minidoka Dam suffers from concrete deterioration on the spillway and both irrigation headworks structures.
The mass concrete placement at the new Minidoka Dam spillway uses a special mixture to keep the heat down during the curing process. This job requires over 400 cubic yards every time a placement is made. That’s enough to fill two average-sized backyard swimming pools. Multiply that times 12 spillway bays, the concrete in the 1300 foot long spillway would top off 24 swimming pools with 5,000 cubic yards.
“It’s not a glamorous job, and it’s some of the hardest work you’ll ever see. The crews don’t stop for lunch or breaks,” says Bureau of Reclamation Construction Inspector Jared Schofield.
“The concrete must be placed before it sets so they’ve got to keep going no matter how tired they are.”
Structural concrete work for the new spillway will be completed by July. It’s the first phase of a four year construction schedule that’s been carefully planned to accommodate irrigation deliveries and flood control operations at the dam.
Minidoka Dam is a combined diversion, storage, and power structure located on the Snake River east of Burley, Idaho. Water diverted from the dam irrigates over 120,000 acres of farmland.