RRHP work resumes upstream as waters recede; Lake Red Rock 50th anniversary celebrated
Aug 06, 2019
Work on the Red Rock Hydroelectric Project has resumed on the upstream side of Red Rock Dam as water levels have receded. Those levels were more than 774 feet above sea level as of June 1, but have since dropped below the level of the upstream work platform.
Work continues on the downstream side of the dam. Final equipment installation, verification, and equipment checks are in full swing and the switchyard, located between the dam and the powerhouse, is nearly complete.
The underground transmission cable from the powerhouse to the overhead transmission line has been installed and final testing started July 8. The transmission line is expected to be energized the first week of August.
Lake Red Rock is a reservoir on the Des Moines River. It was built for flood control 50 years ago. A celebration of this milestone was held during the 2019 Lake Red Rock Balloon Fest July 12-14.
The U.S. Army Corps of Engineers (USACE) monitors, maintains, and determines water flow exiting the Red Rock Dam into the Des Moines River in accordance with its water control manual. Even with the addition of the hydroelectric project, the primary purpose of Lake Red Rock will remain flood control.
When RRHP becomes operational, currently scheduled for 2020 barring additional flood events, the USACE 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. Future releases will first be directed through the new hydroelectric facility. Releases still may be made through the existing gates 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.
RRHP is owned by the Western Minnesota Municipal Power Agency and will be operated by MRES.
The Federal Energy Regulatory Commission license for RRHP allows for the generation of 36.4 megawatts of electricity. The current design model indicates that,to achieve this level of generation, it would take up to 10,000 cubic feet per second (cfs) of water flow. The minimum flow for the hydroelectric facility would be 1,200 cfs. When flows drop below this minimum level, the turbines will not operate efficiently so the facility will be taken out of operation.
Once fully operational, RRHP will be able to generate enough power to satisfy the electrical needs for all the homes in Marion County.