05-5923. Intent To Prepare a Draft Environmental Impact Statement and Dam Safety Assurance Program Evaluation Report for Harlan County Lake Located in Harlan County, Nebraska Near the Cities of Alma and Republican City, NE

AGENCY:

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

ACTION:

Notice of intent.

SUMMARY:

The U.S. Army Corps of Engineers, Kansas City District, intends to prepare a Draft Environmental Impact Statement (DEIS) and Dam Safety Assurance Program (DSAP) Evaluation Report for Harlan County Lake. Harlan County Lake is located near the cities of Alma and Republican City, Nebraska, immediately north of the Nebraska-Kansas border. The dam provides irrigation water supply to areas on both sides of the state line and flood control for the Republican River Basin between Harlan County, Nebraska and Milford Lake located in east central Kansas near Junction City, in Clay and Geary counties. The DEIS study will analyze the economic, environmental, and social impacts that may occur as a result of the various alternatives solutions being considered in the DSAP Report for Harlan County Lake, The DSAP Report will analyze both structural and non-structural solutions for Harlan County Dam's current tainter gate operational issues, the dam's overall hydrologic adequacy, spillway stability and the interdependence of all these factors on the performance of the dam.

FOR FURTHER INFORMATION CONTACT:

Eric S. Lynn, Project Manager, Plan Formulation Section, ATTN: CENWK-PM-PF, U.S. Army Engineer District, Kansas City, 601 East 12th Street, Kansas City, Missouri 64106-2896, Phone [phone] or e-mail to: [e-mail]. Additional information is also available on the Harlan County Dam Project Web site http://www.nwk.usace.army.mil/​projects/​hcdsap/​.

SUPPLEMENTARY INFORMATION:

1. Background

The Republican River Flood of 1935 resulted in major property damage in the Republican River Basin and the loss of 113 lives. The Harlan County Dam project was authorized under the Flood Control Act of 1941, Public Law 228, 77th Congress, as part of the Missouri River Basin Comprehensive Plan. The Flood Control Act of 1944 authorized project purposes of flood control, irrigation, fish and wildlife, and recreation. The U.S. Bureau of Reclamation manages Harlan County Dam's 150,000 acre-feet of storage allocated for irrigation. Harlan County Dam began operation in 1952 will full multipurpose pool being achieved in 1957. Engineering analysis of Harlan County Dam's 18 tainter gates indicated operating issues if the gates were required to operate as designed under full water load conditions to control reservoir water levels to the top of flood control pool elevation of 1973.5 feet, mean sea level (msl). The tainter gates are 30 feet by 40 feet made of structural steel. The design of the Harlan County Dam tainter gates is similar to the Folsom Dam tainter gates that experienced structural and mechanical failure in 1995. Harlan County Dam engineering studies resulted in the adoption in 2003 of a 5-year Interim Operating Plan for Harlan County Dam with top of flood control pool elevation being lowered to 1960.5 msl. At this lower elevation only 17.5 feet of water would be on the gates prior to releasing of floodwater as compared to approximately 30 feet of water if the gates were completely operating as designed. The maximum height on the gates to date is 12.5 feet. The Interim Operating Plan has resulted in the reduction of the flood control storage capacity of the reservoir by approximately 50 percent from 500,000 acre feet to 227,000 acre feet. To date, this lower storage capacity has had no effect on the dam's operation for flood control, irrigation, recreation, or fish and wildlife use. The Interim Operating Plan's top of flood control pool of 1960.5 msl elevation is 4.8 feet higher than the Dam's highest historic pool elevation. Engineering analysis indicates that if corrective action is not taken the gate mechanisms will probably continue to corrode and deteriorate requiring potentially more stringent operating restrictions at some point in the future. There are substantive economic, social, environmental and cultural issues associated with alternatives being evaluated for the operation of Harlan County Dam including flood control, irrigation, agriculture, recreation, tourism, cultural resources, aesthetics, transportation, project costs, and other factors to be identified during the scoping process.

2. Scoping Process

The one or more scoping meetings planned during 2005 for the Dam Safety Assurance Program will also provide information to the public regarding the Harlan County Dam Interim Operating Plan and the potential impacts this Plan may have on the Republican River Basin. The scoping meeting(s) will be advertised in local newspapers, and a mailing list will be used to notify the public and other interested parties of the meetings. The public, native American tribes, and affected government agencies at the local, State, and Federal level are encouraged to participate in the scoping process by forwarding written comments to the above noted address. The scoping process is designed to obtain comments and input for the DEIS and DSAP Report from the public concerning alternative measurers that may be considered for the future operation of the Harlan County Dam. Interested parties may also request to be included on the mailing list for public distribution of meeting announcements and the status of EIS document preparation. Environmental consultation and review will be conducted in accordance with the requirements of the National Environmental Policy Act of 1969, as per regulations of the Council of Environmental Quality (Code of Federal Regulations Parts 40 CFR 1500-1508), and other applicable laws, regulations, and guidelines.

3. Availability of EIS Documents

The availability of the Draft and Final EIS will be presented in the Federal Register and by notices in the local newspapers. The mailing list will also be used to notify interested parties of the availability and location of the Draft and Final EIS for public review.

Dated: March 11, 2005.

David L. Combs,

Chief, Planning Branch, Kansas City District, Corps of Engineers.