Session D6 - Shad and Eel Passage at the Conowingo Project

Exelon Generation Company, LLC (Exelon) has initiated with the Federal Energy Regulatory Commission (FERC) the process of relicensing the 573-megawatt Conowingo Hydroelectric Project (Conowingo Project) on the Susquehanna River. The current license for the Conowingo Project was issued on August 14, 1980 and expires on September 1, 2014. FERC issued a final study plan determination for the Conowingo Project on February 4, 2010, approving a revised study plan with certain modifications. The final study plan determination required Exelon to conduct studies related to the existing fish lifts and potential American Eel passage measures at the Conowingo Project. The assessment related to the existing fish lifts required the Licensee to conduct an engineering analysis of the remaining life cycle and maximum fish passage capacity of the two existing lifts, determine the costs and logistics of upgrading or replacing the existing fish passage facilities, and to assess the logistics and cost of utilizing one or both lifts as an interim measure to increase fish passage at the project via trap and transport methods. The alternatives evaluated ranged from simple upgrades of gates and drive motors to full replacement of the existing lifts, therefore costs and additional passage potential varied significantly. The fish lift portion of the report presents an operational history of the lifts, current maintenance and operations methods, potential upgrades, modifications, or replacements to the current passage infrastructure based on the agency requests, and associated conceptual level cost opinions and drawings. Where appropriate, estimates are provided for the increased passage capacity of the various options. The final study plan also required the Licensee to conduct biological and engineering Studies of American Eel, which included a literature review of available scientific and commercial eel information, characterizing the local eel abundance via field studies, and examining the engineering feasibility and costs of passage options. For the eel study, conceptual layouts and cost opinions were developed for potential upstream eel passage alternatives. The alternatives ranged from eel passage facilities of limited length with a trap-and-transport program to full-length eel passage facilities that provide the opportunity for full volitional passage to Conowingo Pond. The existing fish lifts were installed primarily to provide a passage route for American shad, an anadromous species. The American eel is a catadromous, panmictic population. These two competing migratory strategies present an interesting challenge for management agencies and the Licensee. This paper presents a summary of the alternative analyses prepared for both species and discusses the implications of attempting to satisfy the proposed restoration goals for both populations.
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