1I1: Construction and Monitoring of Nature-Like Fishways for Lake Sturgeon, American Eel, and fish of the Oswegatchie River
July 13, 2022
Water and Environment (including Social Issues)
The Eel Weir and Heuvelton Hydropower Developments are located on the Oswegatchie River in St. Lawrence County, New York, where the New York State Department of Environmental Conservation (NYSDEC) is focusing on lake sturgeon recovery. The Heuvelton Development is located approximately seven miles upstream of the Eel Weir development, which is the next-to-last dam on the Oswegatchie River. The developments were relicensed as part of a six-development Project license in 2012, where fishways were required to be constructed at the two most-downstream developments to facilitate upstream passage of lake sturgeon, as well as American eel and additional resident species. The Eel Weir nature-like fishway (NLF) was completed in late 2015, and the Heuvelton NLF was completed in October 2018. Both sites offered unique design challenges, such as high-flow discharge from a dam spillway through the NLF, while the other fishway needed to fit into limited available real estate. Both fishways used local materials for construction where possible, including the use of large, locally sourced stones for creating weirs and pools and the local processing of materials for riprap and fill. Engineers designed the fishway to accommodate post-construction monitoring and video monitoring and electroshocking were conducted for Eel Weir in the Fall of 2017 and Spring of 2018, with additional monitoring scheduled for Heuvelton, but delayed by COVID-19.