Panel of experts commends work at Red Rock Hydroelectric Project

Published July 28, 2015

SIOUX FALLS, S.D. – An Independent Expert Peer Review Panel (IEPR) praised the work and diligence of the engineers, contractors, and Missouri River Energy Services (MRES) following an onsite review of the Red Rock Hydroelectric Project site June 20 – July 1. This was the IEPR’s second onsite review since construction of the project began. The first was in January.

The IEPR was at the site to conduct a Safety Assurance Review (SAR), a requirement of the U.S. Army Corps of Engineers’ Civil Works Review Policy. The SAR is conducted to ensure that good science, sound engineering and public health, safety, and welfare are the most important factors guiding the engineering design and implementation of the project.

The Panel said it was pleased to see the site staff’s continuing attention to detail relative to the potential impact of nonuniform, soil or bedrock conditions that could impact design assumptions.

MRES, an organization of 61 member municipalities in the states of Iowa, Minnesota, North Dakota, and South Dakota, is building the Red Rock Hydroelectric Project at the Red Rock Dam on the Des Moines River near Pella, Iowa. Each MRES member owns and operates a local electric distribution utility and purchases wholesale electricity and energy services from MRES.

The project, when complete in 2018, will provide enough hydroelectricity to power about 18,000 homes. MRES has hired MWH Global as the project engineer and Ames Construction as general contractor.

During its January review, IEPR focused much of its attention on the soilstructure interaction and the details of the ground support systems required to maintain continued support and stability of the existing Red Rock Dam embankment, saying that this “must take precedence over all other considerations, especially during the upstream construction activity.”

The Panel continued to place great emphasis on that aspect of the project in its July review. Its report commended Ames and MWH for developing and implementing high quality unique means and methods to handle the necessary large and deep excavations, complicated heavy reinforcing elements, and concrete placing techniques.

The IEPR reported that test sections of the support systems that are being built to protect the powerhouse verified that the construction means and methods have been successful and should ensure the structural capacity of these important elements.

“In general the Panel is favorably impressed with the construction thus far. The quality of the work by the contractor and the control of the construction being maintained by MWH and the owner are commendable,” the IEPR report concluded.

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For more information, contact Joni Livingston at Missouri River Energy Services, phone: 605-338-4042;

Release no. 15-048