Biological Assessments for a Hydroelectric Dam Project in the Upper New River

Considered the oldest river in North America—and one of the oldest in the world—the New River flows northeast from North Carolina through Virginia before turning northwest into West Virginia where it joins the Gauley River to form the Kanawha River1,2. In Virginia, the Upper New River passes through four dams (Fields, Fries, Byllesby, and Buck) as it extends from the North Carolina border northward into Claytor Lake (~134 km). Aquatic habitats and community structures are significantly impacted by dams through alterations to natural flow and thermal regimes, river processes, water quality, and by blocking species dispersal corridors2. In order to develop effective river management plans that maintain a balance between environmental interests and dam services (e.g., hydropower), a comprehensive understanding of aquatic community structures, dynamics, and habitats are essential. However, available data regarding species’ distributions and habitat descriptions across the Upper New River are often limited, patchy, or outdated and are in need of reassessments. 

Of the four dams dissecting the Upper New River, Fries Dam is currently undergoing relicensing—prompting the need for a review of the biological resources in the vicinity of the hydroelectric project area. To assess longitudinal patterns in fish, freshwater mussel, crayfish, and rare benthic macroinvertebrate assemblages and distributions, we planned a study to survey along an extensive 4-km reach of the Upper New River surrounding Fries Dam. In addition to monitoring aquatic fauna, searches for river-associated, federally threatened Virginia spiraea were included in our assessments. We divided the study area into five distinct reaches for evaluations: the impoundment, the bypass, an 800-m reach adjacently downstream of the bypass, and a reference reach above and below the influence of the dam. Across-taxa standardized surveying took place from mid-summer through early-fall 2016 and 2017 using active and passive sampling techniques, including standardized backpack/boat electrofishing, snorkel observations, SCUBA diving, kick-nets, and seine-haul surveys. Surveys were conducted by biologists from CMI and The Fluvial Fishes Lab (Don Orth; Department of Fish and Wildlife Conservation) at Virginia Tech with additional—and much appreciated—field support and technical assistance from the Virginia Department of Wildlife Resource biologists.

Across the 2016-2017 field seasons, 43 fish (26 native, 17 introduced) species were documented collectively across the five distinct study reaches. Notable fish collections included:

• Bigmouth Chub (Nocomis platyrhynchus), Kanawha minnow (Phenacobius teretulus), New River Shiner (Notropis scabriceps), and Appalachia Darter (Percina gymnocephala)——four endemics to the Upper New River
• Gizzard Shad (Dorosoma cepedianum) in the impoundment——first reported collection of the introduced species above Buck Dam
• Fish assemblages in the impoundment and bypassed reaches were largely (53-57%) represented by introduced species. In contrast, introduced species occurrences in the reference reaches and tailwater habitat comprised only 24-35% of all species encountered. 

In addition, we documented two mussel species--purple wartyback (Cylconaias tuberculata) and state threatened green floater (Lasmigona subviridis), wide-spread distributions of spiny stream crayfish, and several Orders of aquatic macroinvertebrates.