Engineers Corps February 26, 2007 – Federal Register Recent Federal Regulation Documents

The Corps of Engineers (Corps) is preparing a Draft Environmental Impact Statement (DEIS) to address operational changes at Center Hill Dam that could affect pool elevations. Center Hill Dam impounds Center Hill Lake in central Tennessee. The DEIS is necessary to provide National Environmental Policy Act (NEPA) compliance to address changes that could include, but are not limited to water quality, aquatic, riparian, and terrestrial habitat, recreation, water supply, flood storage, economics, hydropower production, and safety as a result of operating Center Hill Lake below normal pool elevations for extended periods of time. Several engineering studies have identified a heightened level of risk at Center Hill Dam due to increasing seepage problems under and around the dam. Since March 2005, the Corps has attempted to keep fall, winter and early spring lake levels from extreme rises due to high inflow. Seepage problems are made worse during continual high lake levels. As a result, the Corps plans to maintain lower lake levels, but still within the operations curve, to reduce pressure on the dam foundation, abutments, and rim walls until a permanent remedy is in place. A major grouting project to address the dam seepage is scheduled for the fall of 2007, followed by installation of a cutoff wall through the earthen portions of the dam and adjoining rim walls. Although not anticipated, the Corps may have to lower the lake pool significantly below the operating pool should seepage conditions worsen, or new information determine this action is necessary to reduce risk. This notice serves to initiate the NEPA process. The Corps plans to prepare and circulate a DEIS which serves to cover possible impacts due to extreme changes in lake levels that could occur during the repair of the dam's foundation and abutments.

The U.S. Army Corps of Engineers (COE), Wilmington District, Wilmington Regulatory Field Office has received a request for Department of the Army authorization, pursuant to Section 404 of the Clean Water Act and Section 10 of the Rivers and Harbor Act, from Figure ``8'' Beach Homeowners Association to develop a management plan for Rich Inlet that would mitigate chronic erosion on the northern portion of Figure Eight Island so as to preserve the integrity of its infrastructure, provide protection to existing development, and ensure the continued use of the oceanfront beach along the northernmost three miles of its oceanfront shoreline. Figure Eight Island is an unincorporated privately developed island located on the southeast coast of North Carolina, approximately eight miles north of Wilmington. The island is bordered to the south by Mason Inlet and Wrightsville Beach; and to the north by Rich Inlet and Lea-Hutaff Island, an undeveloped, privately-owned island. The inlet management plan would involve the repositioning and realignment of the main ebb channel of Rich Inlet to a location closer to the north end of Figure Eight Island. The intended alignment is to be essentially perpendicular to the oceanfront shorelines of the adjacent islands. The new channel position would be periodically maintained with maintenance episodes dictated by natural shifts in the channel position that produce unfavorable shoreline responses on the north end of Figure Eight Island. While the main focus of the project is to relocate the main ebb bar channel, consideration will also be given to possible alterations in Nixon Channel and Green Channel to determine if such modification would enhance the stability of the new channel. Nixon Channel meanders along a southwesterly path on the landward side of the north end of Figure Eight Island; connecting to the Atlantic Intracoastal Waterway (AIWW) at a point approximately two miles west of the Rich Inlet throat. Green Channel meanders to the northeast on the landward side of Lea-Hutaff Island and intersects with the AIWW approximately 1.75 miles north of the Rich Inlet throat. Material dredged from the inlet and channels will be placed along the central and northern portions of Figure Eight Island and, if needed, along portions of Lea-Hutaff Island. The objective of the placement of beach fill along the Figure Eight Island's shoreline is to keep the design fill density less than 50 cubic yards/foot, to avoid the placement of a permanent static vegetation line. This beach fill would be maintained through a program of periodic beach nourishment events with the material extracted from the dredging of Rich Inlet to maintain the inlet in an optimum location.