LIHI Certificate # 51 --- Arkansas River Dam No.2 Hydroelectric Project (FERC No. 3033) Arkansas River, Arkansas
Portland, Maine (April 21, 2010) - The Governing Board of the Low Impact Hydropower Institute at their regular monthly meeting determined that the Arkansas River Hydroelectric Project meets the LIHI Certification Criteria.
In reaching its decision to certify the Arkansas River Hydroelectric Project, the Low Impact Hydropower Institute's Governing Board reviewed the application for certification, as well as the Application Reviewer's report. The Board's vote to certify the Arkansas River Hydroelectric Project was unanimous. LIHI received no public comments on this application.
The certification for five years of the Arkansas River Hydroelectric Project is granted with the certification time period beginning on January 19, 2010. The certification of the Arkansas River Hydroelectric Project will expire on January 19, 2015.
During the time the Arkansas River Hydroelectric Project is certified, you may market the Arkansas River Hydroelectric Project facilities as a LIHI certified facility.
It is your responsibility to maintain compliance with the certification criteria and to notify us of any changed conditions relevant to the certification. This could include changes in agency recommendations, or changes in operations. You will also be asked to fill out a short form each year to confirm compliance during the preceding year. The Institute may also conduct occasional follow-up checks with you and/or relevant resource agencies to ensure that the Arkansas River Hydroelectric Project remains in compliance.
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LIHI Pending Application -- (FERC No. 3033) Arkansas River Dam No.2 Hydroelectric Project on the Arkansas River, Arkansas
Portland, Maine (January 19, 2010) – The Low Impact Hydropower Institute (LIHI) announced today that Arkansas Electric Cooperative Corp, ("AECC" or "Applicant") has submitted an application for certification of the Arkansas River Dam No.2 Project ("Project"). The Project is located on the Arkansas River about 15 miles southwest of Dumas, in Desha and Arkansas Counties, Arkansas.
The Arkansas River Dam No. 2 Project is one of a number of hydroelectric projects constructed by retrofitting existing dams on the Arkansas River. Arkansas Electric Cooperative Corporation (AECC), a rural electric cooperative corporation, developed the projects to reduce long-term costs of producing energy for its 17 distribution cooperatives around the state and, equally important, to displace a portion of AECC's fossil-fuel derived energy with energy generated from renewable hydropower. No other forms of renewable energy such as wind, solar, and geothermal energy were or are economically or technically competitive with low-head hydroelectric generation in Arkansas.
Arkansas River Dam No. 2 is part of the McClellan-Kerr Arkansas River Navigation System (McClellan-Kerr). The McClellan-Kerr is a 445-mile-long-waterway with 18 locks and dams; for a majority of that distance, it and the Arkansas River are one and the same. The U.S. Army Corps of Engineers (Corps) constructed the waterway to achieve the primary goal of allowing barge traffic to overcome a 420-foot elevation difference between the Mississippi River and the head of navigation at Catoosa, Oklahoma. The Corps constructed the McClellan-Kerr between 1964 and 1970; Arkansas River Dam No. 2, also known as the Wilbur D. Mills Dam, was constructed between 1963-1968.
On August 10, 1983, the Federal Energy Regulatory Commission (FERC) issued to AECC a 50-year license for the Arkansas River Dam No. 2 Project. Due to construction challenges and other factors AECC did not begin building the project until the 1990s. In 1994 AECC obtained a Clean Water Act Section 404 (wetland fill) permit from the Corps. The project underwent regulatory review by state and federal natural resource, environmental, and cultural resource agencies in the early 1980s and again in the early 1990s.
The project is located at the Corps navigation Dam No. 2 on the Arkansas River, two miles southeast of river mile 19 on the McClellan-Kerr Arkansas River Navigation System. The Corps constructed the dam to impound and maintain a minimum nine-foot deep navigation pool along this section of the Arkansas River. Built in the mid 1960s, the dam is located in Arkansas and Desha Counties approximately 12 miles northeast of Dumas, Arkansas.
The dam consists of a gated spillway and an earthfill overflow and non-overflow embankments. The spillway section is a straight concrete gravity type structure with a crest length of 1130 feet and 54 feet at the maximum height. Sixteen conventional tainter gates in the spillway control the upstream pool. The Corps constructed a non-overflow earth embankment on the west end of the dam to block the old Arkansas River channel. The access road to the dam is located on this non-overflow embankment which measures 3150 feet in length. The embankment has a crest elevation of 180 feet M.S.L. In the mid 1990's, AECC constructed the hydropower project as an integral part of this embankment. The hydropower facility included development of a reinforced concrete powerhouse with upstream and downstream channels to divert water from the Arkansas River. The channels pass water from Pool 2 (upstream of the existing Corps dam) through the powerhouse and immediately return it to the river downstream of the dam.
A headrace channel was constructed to divert the river flow and convey it into the powerhouse. Rip-rapped slope banks and reinforced concreted training walls forming the sides of the channel were built upstream from the powerhouse. Beyond the training walls, the stabilized sides of the channel were sloped to meet existing ground level. A log boom across the headrace is intended to trap large debris; however, a trash rack crane on the powerhouse is required to clear the trashrack of the extensive debris the Arkansas River can deliver. Water flow is directed back into the river by the tailrace channel. A portion of the existing navigation revetments were removed to construct the headrace and tailrace channels. These channels provide a transition to the undisturbed revetment areas.
The powerhouse is approximately 180 feet wide by 225 feet long. The upstream face of the powerhouse is located about 500 feet downstream from the dam axis. The powerhouse structure is located on the west side of the Arkansas River adjacent to the dam on the existing non-overflow embankment. The powerhouse elevation is at least as high as the non-overflow embankment. For this reason the high roof of the powerhouse will always be above flood level.
The hydropower project was completed and began operation in 1999.
Public Comments - We encourage public comments on this application. Specifically, we are interested in knowing whether you think the Arkansas River Dam No. 2 Hydroelectric Project meets our LIHI criteria. Review the program and criteria in greater detail and then review the Arkansas River Dam No. 2 Hydroelectric Project's application. Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc) will be most helpful, but all comments will be considered.
Comments may be submitted to the Institute by e-mail at info@lowimpacthydro.org with "Arkansas River Dam No. 2 Hydroelectric Project comments" in the subject line; by fax at (206) – 984-3086; or by mail addressed to LIHI, 34 Providence Street, Portland, ME, 04103. Comments must be received at the Institute on or before 5 pm Eastern time on March 19, 2010 to be considered. All comments will be posted to the web site and the applicant will have an opportunity to respond. Any response will also be posted.