E9-10731. Rescission of Draft Environmental Impact Statement for Proposed Dam Powerhouse Rehabilitations and Possible Operational Changes at the Wolf Creek, Center Hill, and Dale Hollow Dams, Kentucky and Tennessee

AGENCY:

Department of the Army, U.S. Army Corps of Engineers, DoD.

ACTION:

Notice.

SUMMARY:

Pursuant to the National Environmental Policy Act (NEPA), the U.S. Army Corps of Engineers (Corps), Nashville District published its intention to prepare a Draft Environmental Impact Statement relating to proposed dam powerhouse rehabilitations and possible operational changes at the Wolf Creek, Center Hill, and Dale Hollow Dams in Kentucky and Tennessee. Instead, the Corps has decided to evaluate impacts associated with Center Hill Dam powerhouse rehabilitation with an Environmental Assessment (EA). Separate EAs will also be prepared for powerhouse rehabilitations at Wolf Creek and Dale Hollow Dams in the future. Each of these rehabilitation projects are unconnected stand-alone projects that will occur at different times and in different geographic areas.

ADDRESSES:

Send written comments and suggestions concerning this proposed project to Chip Hall, U.S. Army Corps of Engineers, Nashville District, P.O. Box 1070, Nashville, TN 37202-1070. Electronic mail: [e-mail]. Requests to be placed on the mailing list should also be sent to this address.

FOR FURTHER INFORMATION CONTACT:

Chip Hall, Telephone: [phone].

SUPPLEMENTARY INFORMATION:

1. Background. The hydropower major rehabilitation evaluation study for Center Hill Dam was conducted under the authorities of ER 1130-2.500, December 27, 1996, Partners and Support (Work Management Policies), Chapter 3—Major Rehabilitation Program; EP 1130-2.500, December 27, 1996, Partners and Support (Work Management Policies), Chapter 3—Major Rehabilitation Program; and EC 11-2-179, March 13, 2000, Corps of Engineers Civil Works Directorate Program, Program Development Guidance, Fiscal Year 2000. Key proposed project features or issues that were evaluated in the DEIS included the following:

a. Rehabilitation of turbines including installation of Auto Venting Turbines to improve dissolved oxygen (DO) levels in the tailwaters.

b. Providing minimum releases to ensure continuous flows between periods of generation.

c. Evaluating the effects of increased tailwater flows on downstream resources, and changes to the hydraulics and hydrology of the rivers.

d. Other alternatives to be studied included: No Action; restoration to the “original” 1948 condition; refurbishing existing units; oxygenating water in the dam forebays prior to release; and releasing water through the sluice gates.

2. Public Participation. This study was originally initiated in 2003, at which time a Scoping Letter was issued to all known interested individuals and a Notice of Intent (NOI) was published in the Federal Register on September 25, 2003 (68 FR 55376). Due to funding constraints the study was stopped in 2004 before a Draft EIS could be prepared. The study was reinitiated in November 2007 and a second NOI published in the Federal Register on November 26, 2007 (72 FR 65950). A Draft Environmental Impact Statement (DEIS) was distributed to pertinent federal and state agencies and a Notice of Availability was placed in the Federal Register in April 11, 2008 (73 FR 19834).

3. Changes during the Environmental Review Process. Since the DEIS was distributed to the public, it was determined that turbine operations, post proposed power plant rehabilitations, would be subject to the existing Water Control Manuals which govern how each Dam and Reservoir Project and the Cumberland System as a whole is operated. The turbines would be capable of discharging more water; however, turbine gate settings will limit discharges under non-spilling operations to previously existing rates. This significantly reduces the potential impacts of the alternatives being evaluated as flows during normal hydropower generation would be unchanged. However, during extreme flood control situations, it is possible that water that was previously spilled from the project could be passed through a turbine. At the onset of the DEIS, potentially higher hydropower discharge rates were being considered for normal post-rehab operations. The DEIS did not take this limitation on flows into account.

It was also determined that because Dale Hollow Dam did not have any specific recommendations or proposals for rehab, it is premature for it to have been included with Center Hill and Wolf Creek projects. Therefore, it was determined that the DEIS should be rescinded and that an Environmental Assessment should be prepared to determine any significant impacts related to Center Hill Hydropower Rehabilitation Project.

4. Schedule. It is anticipated that an Environmental Assessment will be prepared for the Center Hill Hydropower Rehabilitation Project and will be available for Public Review by June 2009.

Bernard R. Lindstrom,

Lieutenant Colonel, Corps of Engineers, District Engineer.