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Finding of No Significant Impact

Adoption of Environmental Assessments (EAs) prepared by the U.S. Army Corps of Engineers (USACE) and Federal Highway Administration (FHWA)

Section 26a approval for Tennessee State Route 91 proposed wetland impacts, channel relocation, culvert extensions, and streambank stabilization, Carter County, Tennessee

Tennessee Department of Transportation (TDOT)

Background
Alternatives and Impact Assessment
TVA Review
Mitigation
Public and Intergovernmental Review
Conclusion and Findings

Background

TVA proposes to approve construction of improvements for Tennessee State Route (SR) 91. On June 11, 2002, TDOT submitted a joint application to TVA and USACE for channel relocations, culvert extensions, and wetland fill affecting Davis Branch and its tributaries. These actions are associated with the improvement and realignment of SR 91, from SR 37 in Elizabethton to west of Green Valley Road in Carter County, Tennessee, a distance of 2.355 miles. A Section 26a approval would be needed for the following actions, listed from west to east:

  • Channel relocation and temporary wetland fill (0.363 acres)
  • Wetland fill (0.014 acres) and temporary wetland fill (0.009 acres)
  • Culvert and streambank stabilization at unnamed tributary to Davis Branch
  • Culvert replacement at Davis Branch
  • Culvert extension and streambank stabilization at Davis Branch
  • Wetland fill (0.182 acres) and temporary wetland fill (0.011 acres)
  • Channel relocation and culvert extension at unnamed tributary to Davis Branch
  • Channel relocation and culvert extension at unnamed tributary to Watauga River

Under the terms of a Memorandum of Understanding between TVA and the Department of the Army, dated August 12, 1985, TVA served as a cooperating agency in the preparation of the USACE EA. TVA commented on a draft of the USACE EA. The proposed culvert extensions, channel relocation, and filling of wetlands require approval under Section 26a of the TVA Act. Because the project included wetland and stream mitigation, TVA decided that an EA would allow a better understanding of the impacts of this proposal. TVA has determined that the impacts of its Section 26a approvals for the improvements on SR 91 from SR 37 in Elizabethton to west of Green Valley Road in Carter County are adequately assessed in the USACE EA and FONSI of October 22, 2002, and the FHWA EA and FONSI of November 29, 1999. TVA adopts these documents as its own, based upon independent review of the project.

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Alternatives and Impact Assessment

The USACE EA dated October 22, 2002, evaluates the environmental consequences of two alternatives, No Action, and the Applicant’s Final Proposal. Under No Action, the improvements to SR 91 would not be completed. Under the Applicant’s Final Proposed Action, SR 91 would be improved by constructing additional lanes along 2.355 miles of highway, 0.827 acres of wetland would be permanently filled, with a 2:1 mitigation occurring at the Shady Valley Wetland Mitigation Bank. The project would result in the fill or relocation of 755 feet of existing stream channel at several locations. A new alignment was considered by the applicant, however, it was determined not to be feasible. The widening of the roadway along the existing alignment is the most feasible and economical alternative for the proposed project.

The FHWA EA dated November 29, 1999, evaluates the environmental consequences of two alternatives, the “No-Build” Alternative and the “Build” Alternative. Under the No “Build” Alternative, no improvement to the existing facility would be made other than routine maintenance activities. The present automobile accident rate would continue and would allow an increasingly dangerous situation to continue. The projected level of service for this roadway under the No “Build” Alternative would be changed from the current “E” to “F” in the year 2018.

Under the “Build” Alternative, additional lanes would be added along 2.355 miles of the existing SR 91 to correct roadway deficiencies and improve the safety and efficiency of the highway. The level of service would improve from an E to a B level, which is reasonable free flow operations. Less than one acre (0.827 acres) of wetlands would be permanently filled, with mitigation occurring through purchases from the Shady Valley Wetland Mitigation Bank in Johnson County. An additional 0.383 acres of wetlands would be temporarily impacted. As mitigation for the 0.827 acres of wetland that would permanently be filled, TDOT proposes to debit 1.65 acres (2:1 ratio) from the Shady Valley Wetland Mitigation Bank in Johnson County, Tennessee. Temporary impacts to wetlands would be mitigated by planting winter rye and trees to re-establish cover as quickly as possible. Mitigation proposed for stream impacts includes relocation of the streambed and planting of trees to develop canopy. No historic properties would be affected, and there would be no effects to endangered and threatened species. The project would not disproportionately affect minority or low income populations.

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TVA Review

TVA independently reviewed the impacts assessed in the USACE EA and confirmed their findings. TVA determined that impacts to aquatic resources would be minimized through the use of standard Best Management Practices for water quality protection. The proposed project involves modifications to existing culverts. For compliance with Executive Order 11988, culverts are considered to be repetitive actions in the floodplain. The project would comply with the requirements of the National Flood Insurance Program and be consistent with Executive Order 11988. Both Elizabethton and Carter County participate in the National Flood Insurance Program. For seeding of wetland areas, native species have been specified. As a cooperating agency, TVA commented on the draft USACE EA for the SR 91 impacts prior to completion. The proposed mitigation in the Shady Valley Wetland Mitigation Bank is appropriate because there are no suitable on-site mitigation areas. TVA has concluded that with the inclusion of standard Section 26a approval conditions and the commitments contained in the USACE and FHWA EAs, that the EAs are adequate and the impacts on the environment have been adequately addressed.

Other past, present, and reasonably foreseeable future roadway projects with potential to affect similar wetland and stream systems in the area include SR 91 improvements east of the site and the proposed Elizabethton connector west of the proposed site. TVA previously issued permits for 21 stream obstructions or modifications associated with the widening of five miles of SR 91 between Price Road and Panhandle Road in Carter County in 2000. The proposed Northern Connector would extend from the junction of SR 91 and US 19E west to US 321 near Sycamore Shoals (west of Elizabethton). A FHWA EA for the Northern Connector was completed in June 2002. Both of these projects have affected or would affect tributary streams to the Watauga River. However, with the requirement for no net loss of stream and wetlands functions and values, cumulative effects of these projects, when combined with the proposed SR 91 project under consideration, would be insignificant.

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Mitigation

This FONSI is contingent upon successful implementation of Best Management Practices for erosion and sediment control including the TVA standard conditions 5a-e for culverts and conditions 6a-i for construction, the debiting of 1.65 acres of credit from the Shady Valley Wetland Mitigation Bank, and on site mitigation for temporary impacts to 0.383 acres. The applicant would replant the temporarily impacted area with native wetland tree species and winter rye in order to adequately offset the temporary impacts to the 0.383 acres.

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Public and Intergovernmental Review

On July 16, 2002, Public Notice 02-48 was issued. Comments were received from the U.S. Fish and Wildlife Service (FWS) and the Tennessee Historical Commission (THC). FWS concurred that the proposed wetland mitigation was adequate and determined that there were no project related impacts to threatened and endangered species and their habitats. THC stated that the undertaking would have no effect on National Register of Historic Places or eligible properties. TDEC issued the certification required under Section 401 of the Clean Water Act on September 9, 2002.

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Conclusion and Findings

TVA has critically and independently reviewed the USACE and FHWA EAs and determined that the scope, alternatives considered, and content of the EAs are adequate and that the impacts on the environment have been adequately addressed. TVA has decided to adopt the USACE and FHWA EAs. They are attached and incorporated by reference. TVA has determined that no historic properties or threatened and endangered species would be affected by the SR 91 project.

Based on the EAs, we conclude that the Section 26a approvals for the proposed improvement on SR 91 in Carter County would not be a major federal action significantly affecting the environment. Accordingly, an environmental impact statement is not required. This FONSI is contingent upon successful implementation of Best Management Practices for erosion and sediment control, the debiting of 1.65 acres of credit from the Shady Valley Wetland Mitigation Bank, and on site mitigation for temporary impacts to 0.383 acres of wetlands.

Original signed by:
Jon M. Loney
Manager, NEPA Administration
Environmental Policy and Planning
Tennessee Valley Authority

Date: November 22, 2002

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