Planning Guide for Fish Passage at Pittsburgh District Dams

Background. The US Army Engineer (USACE) District, Pittsburgh (LRP) is preparing the "Upper Ohio Navigation Study, Pennsylvania" Feasibility Study and Integrated Environmental Impact Statement (EIS). This study will examine alternatives for replacing aging navigation locks on the three uppermost navigation facilities on the Ohio River: Emsworth, Dashields, and Montgomery (EDM) Locks and Dams. Specifically, LRP has recommended replacing the 56-ftwide auxiliary (riverside) lock at each facility with a new 110-ft-wide main chamber. This action will require encroachment into the dam, eliminating one gate each at Emsworth and Montgomery gated dams, and a section of the Dashields fixed crest dam. The plan at Dashields includes a new gate for additional flow capacity. LRP was directed by the USACE Great Lakes and Ohio River Division (LRD), through the Ohio River Mainstem System Study, to consider fish passage strategies as part of this study. LRP staff, with assistance from U.S. Fish and Wildlife Service biologists and engineers, determined that separate fish passage facilities for these dams were infeasible. However, it was also determined that fish passage could possibly be improved by modifying design features of the replacement navigation facilities themselves. LRP staff has recommended further consideration of fish passage in the Preconstruction Engineering and Design (PED) phase, which will occur after completion of the Feasibility Study and Integrated EIS. The intent, consistent with the Corps’ Environmental Operating Principles and good environmental design, is to consider navigation design features that may limit upriver movement of nonnative species, but facilitate movement of both commercial traffic and native fishes. Modernizing outdated navigation locks will present an opportunity to evaluate design or operational features at the EDM facilities during PED phase, supporting LRP’s commitment to evaluate fish passage. LRP envisions that the upstream fish passage strategies considered for these three projects would be broadly applicable to all inland river navigation facilities.