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 to 747 feet, which is 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.
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. 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. 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 hydroelectric 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.