| Fish passage
important for others to hear and consider applying these to their work at new or existing facilities. Lessons learnt include:
● Benefiting greatly from collaborating with and seeking the guidance of experts, and their efforts to regularly connect with academia, government agencies, and other utilities were invaluable.
● Engaging with parties such as Indigenous nations and regulatory agencies early on and throughout the process. This will help alleviate concerns, reach common ground, and lead to stronger relationships and partnerships to continue advancing this important work.
● Taking the time to carefully consider the location and orientation of the fishway entrance.
● Designing and planning for future conditions and operational flexibility.
● Incorporating operator safety into the design. BC Hydro said it recognised early on that the design principles and criteria were often focused on maximising fish health and survival and less on the safety of the people tasked with operating and maintaining fish passage facilities. BC Hydro says worker safety was a top priority at Site C because the need to sort and transport fish introduced operator involvement and potential hazards that needed to be controlled.
Burnett et al conclude that despite improvements in attraction efficiency, passage and trapping success, there is still room for improvement in the biological effectiveness of the permanent facility at the John Horgan Dam. They believe sharing their lessons should prove useful to practitioners, natural resource managers, biologists, and engineers involved in new or existing fish passage projects elsewhere. .
CONUS Census The current state of knowledge regarding the
implementation of fish passage infrastructure at hydropower projects in the US is described as being incomplete and outdated. Understanding where, how, and why fish passage facilities are installed is particularly important in today’s rapidly evolving hydropower landscape, as the US hydropower community (resource managers, regulators, industry, and environmental advocacy groups) seeks to modernise and strengthen its hydropower fleet while simultaneously implementing effective basin-scale fisheries management. In the first conterminous US (CONUS)-scale dataset of fish passage facilities at US hydropower developments in over 30 years, Matson et al identified 2729 active hydropower features as potentially impeding the movement of migratory fish within rivers. Their dataset reported the existence (presence or absence) of fish passage facilities at 70% of these hydropower developments, 390 of which had at least one fish passage facility, and almost half were licensed by FERC. Fish passage facilities were most common at FERC licensed projects, followed by US Army Corps of Engineers-owned features, then FERC exempt features, those with unknown regulatory status, and finally Bureau of Reclamation projects. Most had a single passage facility that provided passage in only one direction, with downstream being more common than upstream passage. Bypasses and ladders accounted for 60% of the fish passage facility types. Fish passage
facilities were most common in the New England, Pacific Northwest, Mid-Atlantic, and Great Lakes regions. The research team also identified regions where information is lacking, particularly in California and the Mountain West. In general, fish passage facilities were more common at features that were closer to the ocean, at lower elevations, and at shorter dams, but not related to installed electrical generation capacity. Hydrologic sub-basins containing salmonids also contained the largest number of hydropower features, but the proportion of features with passage was generally higher in sub-basins containing multiple migratory taxa. As the authors explain in their study published in The Journal of Environmental Management, hydropower developments represent a very small fraction (<3%) of the 92,000 dams that could potentially impede the movement of migratory fish species.
“Consequently,” Matson et al say, “this dataset should not be construed as a tool to evaluate connectivity; rather, it is a census of our progress toward building a hydropower fleet that simultaneously protects valuable fishery resources while providing affordable, reliable energy for the benefit of the American public.” Of all FERC-licensed features included in this dataset, 40% will be within five years of licence expiration by 2035, the point at which pre-filing consultation stages of the relicensing process would be expected to begin. Results presented in this study show there are likely to be many developments that may be required to install passage facilities for the first time, or upgrade existing facilities to improve efficacy, or accommodate additional migratory species as a condition of obtaining a new licence. Eels also present a different challenge for fish passage given their unique life history and swimming and climbing capabilities. Downstream passage of adult eels is challenging because their behaviour, size, and shape make it difficult to prevent turbine passage using traditional fish protection measures. Passage facilities that were specified in the dataset as applying to eels are likely not useable by other species. Eel-specific passage facilities in the dataset were highly variable, ranging from simple spat ropes that juvenile eels can use to climb over a spillway, to mechanical eel lifts that require supervisory control and data acquisition systems. Some hydro developments may alter their operational schedule during certain times of year and day (such as nightly shutdowns) when eels migrate downstream to try to prevent entrainment, injury, or mortality associated with through-turbine passage. The authors also add that recent advances in fish-friendlier turbine technology are promising for safe turbine passage for eels (100% survival after 48hours) and other fish, with no or very low mortality. Unfortunately, the authors conclude that the presence of fish passage facilities “does not automatically equate to safe, timely, and effective passage of large numbers of migratory fishes”. A central issue to quantifying passage efficacy is the
lack of specificity in what it means to be successful, both in terms of defining and evaluating the targets for passage performance. Matson et al give the example of counting the number of fish that exit the upstream end of a fishway as one method of assessing performance. However, this does not provide insight into how many fish encountered (or could not locate) the downstream entrance, or how long it took fish to navigate the fishway. Matson et al say their census “provides
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