Des Moines River, about 2.5 miles southwest of Pella, Iowa

Size of Dam

Length is 5,676 feet; height is 110 feet

Energy Production

178,000 megawatt-hours (estimated annual average)

Energy Sources

43% of our members’ energy comes from federal hydroelectricity, wind, and solar.

Investing in the


Hydropower ranks as the most common source of renewable energy used to generate electricity, and accounts for 6 percent of total U.S. electricity supply. According to the National Hydropower Association, hydropower accounts for 38% of all renewable energy generation in the United States. In the four-state region served by Missouri River Energy Services (MRES) members and other utilities, hydropower accounts for 5.2 million megawatt-hours (Mwh) of the region's electric generation.



The U.S. Army Corps of Engineers, Rock Island District to reopen the North Tailwater Recreation Area

Sep 15, 2020

The U.S. Army Corps of Engineers, Rock Island District will reopen the North Tailwater Recreation Area below Lake Red Rock Dam on Oct. 1 for public use.

The area has been closed since fall 2014 due to construction of the new Red Rock Hydropower Project.

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MRES to host video dedication ceremony

Sep 02, 2020

Missouri River Energy Services is celebrating the dedication of the Red Rock Hydroelectric Project by hosting a premiere showing today, starting at 2 p.m. CDT. The ceremony will be held via video on our social media pages and will feature messages from a variety of distinguished speakers, along with photos and video of the plant throughout construction. 

For more information about Missouri River Energy Services, please go to www.mrenergy.com. Or find us on Facebook or Twitter at @MRESnews or YouTube: MissouriRiverEnergyServices.

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Major General Diana Holland, Mississippi Valley Division Commanding General of the USACE, provides remarks on RRHP

Sep 02, 2020

Missouri River Energy Services (MRES) extends its sincere thanks to the U.S. Army Corps of Engineers (USACE) for the great working relationship we have enjoyed for the past many years, from the permitting process through project completion. We are honored that Major General Diana Holland, Mississippi Valley Division Commanding General of the USACE provided the following special message for the dedication of the Red Rock Hydroelectric Project.

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RRHP ‘watered up’ for commissioning tests

Aug 01, 2020

Red Rock Hydroelectric Project (RRHP) recently took another step toward completion when wet commissioning of Unit 2 started July 20.

As part of the commissioning process, the hydroelectric plant was “watered up,” where water from the Red Rock Reservoir was allowed to flow into and through the facility for testing purposes.

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RRHP dedication moved to a virtual format

Jun 02, 2020

The Red Rock Hydroelectric Project (RRHP) dedication ceremony scheduled for Aug. 19 has been moved to a virtual format.

Initially, MRES intended on hosting a large on-site celebration to mark the six-year project’s completion and to memorialize the launch of a clean, reliable resource that will serve customers long into the future. Due to the uncertainty surrounding the coronavirus outbreak, however, the MRES board decided during its meeting on June 4 to host a virtual dedication instead. The board’s decision reflects MRES’ commitment to the health and safety of its members, as well as the communities they serve.

A long list of speakers is still on tap for the event, and MRES will provide condensed versions of their speeches, said Joni Livingston, MRES vice president of member services and communications.

“In place of their formal speeches, we’ve asked each speaker to do a short, abbreviated video of what they would have said in person,” she said. “To complement the speaker videos and to replace the plant tours we had planned for that day, MRES staff will put together a slide show and video tour that will provide an inside look at the inner workings and highlights of the plant to an online audience.”

Livingston said the video will be posted online for members to view at their leisure, and that video clips, sound bites, and images will be used on social media as a means of education and outreach to member communities. In addition, MRES staff will be providing members with fact sheets about the project that also show it’s a tangible example of how MRES is working toward a cleaner energy future.

RRHP is a retrofit of the existing U.S. Army Corps of Engineers (USACE) dam on the Des Moines River just southwest of Pella, Iowa, an MRES member community. MRES built the new hydroelectric facility to add to its members’ renewable resource portfolio, and the addition of hydropower will not affect the operation of the original dam, as USACE will continue scheduling water releases as it has since the dam was first built in 1969.

The capacity of the project is rated at 36.4 MW, but during summer months when water levels are typically highest, the plant is capable of producing up to 55 MW of power. Once it’s fully operational, the facility will generate enough power to satisfy the electrical needs of about 18,000 homes.

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Red Rock Dam cored for one unit of hydroelectric project

Oct 25, 2019

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.

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WMMPA prices $322 million of bonds

Oct 21, 2019

The Western Minnesota Municipal Power Agency (WMMPA) will close Oct. 29 on more than $322 million in taxable power supply refunding bonds. This sale will be used to refinance existing tax-exempt bonds that WMMPA issued primarily to finance the construction of the Red Rock Hydroelectric Project that is being built in Iowa along with other projects.

“We used lightning speed to get this issue to market,” said WMMPA Financial Advisor Mike Berwanger of Public Financial Management Company. “We were able to capture a phenomenal market that will result in annual debt service savings of $1.9 million per year in each of the next 26 years.” 

This issue of $322,020,000 will have an all-in true interest cost of 3.13 percent, which is the lowest in WMMPA history. The total savings to MRES members will exceed $50 million over the term of the bonds. Net present-value savings will be $33 million, or 11.5 percent of the refunded bonds.

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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.

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RRHP work progressing downstream; still on hold upstream due to high water levels

Jul 02, 2019

Progress on the intake structure at Red Rock Hydroelectric Project (RRHP) remains on hold on the upstream side of the dam due to elevated water levels on Lake Red Rock.

Water levels were more than 756.6 feet above sea level as of June 28. These levels need to drop to about 748 feet before upstream work can resume. The U.S. Army Corps of Engineers (USACE) estimates that the 748-foot level could be reached July 8.

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