2016-21570. Draft Supplemental Environmental Impact Statement for the Dam Safety Modification Report, Bluestone Dam, Hinton, Summers County, WV

AGENCY:

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

ACTION:

Supplemental Draft Environmental Impact Statement—public and agency comment period.

SUMMARY:

Pursuant to the National Environmental Policy Act (NEPA), the U.S. Army Corps of Engineers (Corps), Huntington District prepared a Supplemental Draft Environmental Impact Statement (SDEIS) to disclose potential impacts to the natural, physical, and human environment resulting from modifications to Bluestone Dam. The original EIS was published in 1998 and a Record of Decision (ROD) was signed in 1999 concluding the NEPA process allowing the Corps to initiate implementation of the Bluestone Dam Safety Assurance (DSA) Project. When completed, the current modifications under construction will strengthen the dam's stability and allow for increased discharge capacity through the use of hydropower penstocks substantially reducing risk. However, physical modeling and expert analysis conducted during project construction indicated the downstream bedrock is vulnerable to an unacceptable degree of erosion during high flow events. The Corps has also recognized potential for unacceptable erosion associated with overtopping of areas of the dam not designed to be overtopped. After a full consideration of alternatives to achieve acceptable risk levels, this SDEIS recommends implementing modifications to the existing stilling basin to prevent scour that could result in spillway instability and thus dam failure. Modification may include alteration to the existing stilling basin to include installation of a concrete apron, larger baffles, and would also include non-structural risk management measures. This SDEIS also addresses the prolonged construction duration of modification features described in the original EIS and ROD.

DATES:

The review period will be open from September 1, 2016 to October 17, 2016.

ADDRESSES:

Send written comments and suggestions concerning this proposed project to Rebecca Rutherford, Chief, Environmental Analysis Section, Planning Branch, U.S. Army Corps of Engineers, Huntington District, 502 Eighth Street, Huntington, WV 25701-2070. Telephone: [phone]. Electronic mail: [e-mail]. Requests to be placed on the mailing list should also be sent to this address.

SUPPLEMENTARY INFORMATION:

1. Authority: Bluestone Dam and Reservoir was authorized by Executive Order (E.O.) 7183 in 1935 and the Flood Control Acts of 1936 and 1938 for the purposes of flood control, low flow augmentation, and hydroelectric power development. The purposes were later expanded to include recreational activities under the Flood Control Act of 1944 and fish and wildlife enhancement under the Fish and Wildlife Coordination Act (FWCA) of 1958.

2. Background: a. Guidance for this study is provided in USACE Engineer Regulation (ER) 1110-2-1156 (October 2011). This guidance details agency policy and procedures for the study and implementation process addressing dam safety issues.

b. Bluestone Lake is a multipurpose component of the Kanawha River basin system which provides for flood control, recreation, power development, low flow augmentation, and fish and wildlife enhancement. The project began operation in 1949 and helps control a 4,565 square mile drainage area.

c. The ROD, signed in 1999, completed the NEPA process for the DSA project permitting the Huntington District to begin detailed design and subsequent construction of the recommended alternative which included a 13 foot cantilever wall on top of the dam, an additional concrete monolith on the east abutment, a floodgate closure across WV Rt. 20, removable closures at each end of the spillway, high strength anchors placed into the dam itself, massive concrete blocks placed against the downstream face of the dam, and a pavement for scour protection downstream of the hydropower penstocks. The majority of the ongoing construction on these measures will continue through the year 2019. The ROD for this work anticipated construction would be completed 2005.

d. Physical modeling and expert analysis conducted during project construction has shown the downstream bedrock is vulnerable to erosion during high flow events as a result of deficiencies with the current stilling basin configuration. This potential erosion creates an unacceptable level of risk according to guidelines established in ER 1110-2-1156, under which this study is being conducted.

e. The SDEIS and Dam Safety Modification report (DSMR) will consider the structural integrity of the dam, its ability to accommodate flood waters as well as transportation, noise, terrestrial, aquatic, economic, environmental justice and cultural resource issues associated with the performance of the dam. The SDEIS and DSMR will recommend any modifications necessary to ensure the long-term safe performance of the structure as originally intended.

f. Modifications to meet current acceptable risk guidelines per ER 1110-2-1156 may include, modification of the existing stilling basin, modification of other dam components, construction of an alternative/auxiliary stilling basin, construction of an alternative/auxiliary spillway and non-structural measures or other actions to prevent overtopping. The No Action alternative will also be considered. As required by NEPA and Corps planning guidance, the No Action alternative will form a benchmark from which alternatives are evaluated and compared.

3. Public Participation: a. The SDEIS will be made available to the public in the affected area for forty-five (45) days for review and comment. A Notice of Availability will be advertised in affected area newspapers informing the general public about the SDEIS public review period. The SDEIS and draft ROD can be viewed at: http://www.lrh.usace.army.mil/​Missions/​PublicReview.aspx. Copies of the SDEIS and draft ROD may be obtained by contacting the Huntington District Office of the Corps of Engineers at [phone] (See ADDRESSES). All persons and organizations that have an interest in the Bluestone Dam Project are urged to participate in this SDEIS review and comment period. Upon the close of the comment period, USACE will consider all comments and if necessary conduct further analysis.

Additionally, the Corps will conduct public meetings to gain input from interested agencies, organizations, and the general public concerning the content, issues, and impacts of the SDEIS, a separate Notice of Intent will be published in the Federal Register for this action. Prior to the meeting, a public notice will be distributed to agencies, organizations, and the general public, informing interested parties of the date and location for the public meeting. The Corps invites full public participation to promote open communication and better decision-making.

4. Schedule: The Draft Supplemental Environmental Impact Statement is scheduled to be released for public review and comment on or about September 1, 2016. The Final Report and Final Supplemental EIS are tentatively scheduled to be completed in May 2017.

Rebecca A. Rutherford,

Chief, Environmental Analysis Section, Planning Branch.