Tapoco Hydroelectric Project Collaborative Relicensing Process

Client: U.S. Forest Service

Location: Three County Area of Western NC

Summary: Under a five-year national contract with the U.S. Forest Service (USFS), Cardno ENTRIX, Inc. provided technical analysis support and strategic consultation to support the USFS?s role as a consulting agency in the collaborative relicensing process for Alcoa Power Generating Inc.?s Tapoco Hydroelectric Project (FERC No. 2169). The project is located in the Little Tennessee River basin of North Carolina and Tennessee and includes three reservoirs and two bypass reaches that border the Nantahala National Forest.

Cardno ENTRIX assisted the USFS and other members of the cooperating Resource Agency Group in evaluation of the potential biological effects of recreational flow release alternatives on the aquatic community of the Cheoah River and developed draft recommendations for releases that would mitigate and minimize those effects. This work required that Cardno ENTRIX provide review and analysis of NEPA documentation, fisheries investigations, the Cheoah River Instream Flow Study, recreational flow studies, and related biological and hydrologic studies. Cardno ENTRIX developed two interactive, spreadsheet-based hydrologic and habitat models to 1) characterize the historic high flow regime of the Cheoah River and regional reference streams, 2) evaluate alternative base flow and high flow regime combinations, and 3) develop an integrated low and high flow regime for the Cheoah River. Cardno ENTRIX also worked with other USFS consultants to conduct substrate transport analyses, assess baseline sediment conditions, and develop a rationale for substrate supplementation to enhance habitat conditions for protected fish and mussel species. Under another task, Cardno ENTRIX coordinated the development of a detailed, GIS based physical habitat map of the Cheoah River bypass reach using high-resolution orthophotography, LIDAR, and hyperspectral imagery data.

The models, other supplemental analyses, and technical memoranda prepared by Cardno ENTRIX were instrumental to the development of the Resource Agency Group?s integrated flow regime recommendation for the Cheoah River, which consisted of a seasonally variable, aquatic base flow component and a natural-like high flow component. The integrated flow regime recommendation balanced the competing water demands of hydropower generation and lake-based recreation, while still achieving aquatic habitat restoration objectives and providing opportunities for white water boating. Cardno ENTRIX products and project contributions were ultimately used to provide strong justification for the USFS position during the development of a Comprehensive Settlement Agreement.