Work continues on schedule at the Lake Red Rock Hydroelectric project.
The recent mild weather has allowed crews to work around-the-clock to prepare for construction of a powerhouse and intake structure. Short-term road closures, directed by the Marion County Sheriff’s Office, will continue during the overnight hours every three to four days as crews move large rebar cages from the North Tailwater staging area. Highway T-15 will also be restricted to one lane intermittently to facilitate staging of concrete trucks and to ensure worker and public safety. A pilot car and flaggers will be directing traffic whenever there is a lane closure.
Ames Construction finished placing the steel sheeting to form Cell #4 of the cofferdam that will help to keep water out of the site during the construction of the powerhouse on the downstream side of the Red Rock Dam. Crews will install the concrete base and fill the cell with sand during the coming week. Next week, they will also begin to install sheeting for a 335-foot “closure dike” that will connect to the cofferdam to the land. Rock will eventually be placed on each side of the closure dike, making it look like another small dam. Both the cofferdam and the closure dike are temporary structures that will be removed when construction of the project is completed.
Also on the downstream side of the Dam, Ames has dug out the first four feet of the powerhouse excavation and has begun installation of the support structure for the secant pile retaining wall. The support structure will consist of a combination of walers (I-beam braces) and 153 tie-back anchors which will be installed as the excavation proceeds. The tie-back anchors will be drilled into bedrock to ensure the stability of the retaining wall.
The first large components of the turbine generators have started to arrive on-site. Voith Hydro of Heidenheim/Brenz, Germany is the supplier of the turbines and major powerhouse equipment.