Dry weather allows for continued headway at hydro project
Steady progress continues at the site of the Red Rock Hydroelectric Project as crews complete the downstream cofferdam and dike and the upstream diaphragm wall at the 760-foot lower bench level.
The dry spring weather has provided good working conditions for the upstream construction of a 240-foot diaphragm wall that will hold back the earthen dam to provide a channel for water to enter the intake structure that sends the water to the turbine/generator.
“There is always a concern about the level of the reservoir,” said Joni Livingston, Director of Member Services and Communications for Missouri River Energy Services. “If the water level comes near the 760-feet elevation work bench, current work activities would have to stop on the upstream side of the dam.”
“The water levels throughout April have ranged from 742 to 744 feet in elevation, well below the 760-foot temporary work platform where construction is currently taking place. Of course, one heavy, fast rain could quickly change everything,” said Livingston. If the water levels remain steady, four more wall elements will be installed over the next two weeks, completing the lower bench work for now. Crews will then construct a temporary work platform at the 780-foot elevation to begin construction of five more diaphragm wall elements.
The movement of rebar cages and resulting overnight short-term road closures has been a critical factor in building this retaining wall. “We are grateful to the public for their ongoing support and patience with the project,” said Livingston.
The cofferdam and closure dike on the downstream side of the dam are nearly complete, which will help keep water out of the site during the excavation and construction of the powerhouse. Excavation for the powerhouse is well underway, along with the installation of tie-back anchors and bracing in the retaining (secant pile) wall.
With the safety of the public and construction workers in mind, the construction areas will remain closed to the public for the duration of the hydro project. Closed areas include the North Tailwater Recreation Area, the North Overlook Picnic Area, and the Volksweg Bike Trail from Howell Station Campground to the North Overlook Picnic Area.
For more information about the Red Rock Hydroelectric Project, contact Joni Livingston at Missouri River Energy Services, phone 605-338-4042 or email: firstname.lastname@example.org.