Red Rock Dam cored for one unit of hydroelectric project

Oct 25, 2019

Red Rock Dam cored for one unit of hydroelectric project

Another milestone was reached Oct. 21 at the Red Rock Hydroelectric Project (RRHP) as construction workers successfully cored through the Red Rock Dam.

Coring through the dam was done to prepare for the installation of a penstock, a conduit which will bring water from the intake structure located in Lake Red Rock into the powerhouse. The powerhouse is where the turbines are located that will use the water to turn the turbine/generator to produce electricity.

Workers next will continue the upstream penstock through the dam by placing rebar and forms around the hole for the placement of concrete. Prior to coring through the dam, the penstock from the intake structure to the existing concrete section of the dam had to be constructed and tested to prove to be watertight. Additionally, the gate that isolates the water from the reservoir from the penstock had to be installed and tested to prove to be watertight so that no water could enter into the penstock during the final construction. The opening of the penstock within the intake structure that the gate covers is 18’ wide by 21’ high.

RRHP is owned by the Western Minnesota Municipal Power Agency and will be operated by Missouri River Energy Services (MRES) (

When complete, RRHP will include two generating units.  This initial coring was for Penstock #2.  The watering up of this penstock is expected around the first of April 2020. Once water is delivered to the turbine in the powerhouse, commissioning and testing of the Unit 2 turbine/generator will begin.  During this period, the plant will be manned around the clock..

Following that test period, Unit 2 could be ready for commercial operation around the first of June.  During and after this period, similar work will be completed for Unit 1 of the plant.

When RRHP becomes operational, the U.S. Army Corps of Engineers Hydrology Department will continue to be responsible for scheduling water releases from the Dam into the river as it has been for the past 50 years. These releases could be directed through the existing gates on the Dam, through the new hydroelectric facility, or through a combination of these depending on the reservoir elevation and desired flow release. Regardless of where the releases are directed, no additional water will flow into the river below the dam than what has occurred in the past.

The Federal Energy Regulatory Commission license for RRHP allows for the generation of 36.4 megawatts of electricity.  Once fully operational, RRHP will be able to generate enough power to satisfy the electrical needs for all the homes in Marion County.

# # # # #

For more information about the Red Rock Hydroelectric Project, visit the project website at or contact Joni Livingston at Missouri River Energy Services, phone 605-261-3637 or email: