Work continues around the clock at RRHP

Jan 19, 2015

Work continues around the clock at RRHP

Work is continuing around the clock at the Red Rock Dam near Pella, Iowa, where Missouri River Energy Services (MRES) will construct a new hydroelectric power plant.  Much of the construction work being done at this time is to lay the groundwork for the construction of the water intake structure and for the power plant itself.

At the site, three projects are being worked on simultaneously.  On the upstream side of the Red Rock Dam, workers are nearing completion of the first “test element” that, if approved, will become one of the 26 concrete elements or partitions that comprise a 240-foot diaphragm wall.  The diaphragm wall will hold back the earthen dam to provide a channel for water to enter the intake structure that sends the water to the generator.  The test element, one of the largest elements in the wall, is a vertical structure approximately 10.5 feet wide, 21 feet long, and 130 feet deep.  It contains about 150,000 lbs. of steel rebar and 720 yards of concrete.  The concrete pour required 72 truckloads of concrete to be delivered to the site with three truckloads continuously pouring concrete into the structure at the same time.  The element is set in 42 feet of bedrock.  The test element is undergoing various tests for strength, proper bonding to the rebar, and quality of the concrete.  When the test element has been completed and approved, work will begin on the remaining elements of the diaphragm wall.  

On the downstream side of the dam, workers are finishing the first of four cells that will comprise a temporary coffer dam, and have begun work on setting the steel sheeting on Cell #2.  The coffer dam will keep water out of the site during the construction of the power plant.  The coffer dam will be filled with sand for the duration of the project.  It will be removed when plant construction is complete.  

Under Highway T-15, a 100-foot long by 85-foot deep concrete wall is being built to ensure dam stability during construction.  When the hydropower project is completed, this wall will remain part of the permanent structure of the dam. Work on the wall is expected to be completed by the end of January, allowing T-15 to reopen to regular traffic soon thereafter. MRES will issue a press release as soon as a reopen date is determined.

Throughout the construction of the Red Rock Hydroelectric Project, regular updates will be available at For more information, contact MRES Director of Member Services and Communications Joni Livingston, phone 605-338-4042; email