Independent review : Potential impacts of run-of-river power hydroprojects on Salmonids

The structure of a typical run-of-river facility naturally separates a project into three sections or stream reaches: the section immediately upstream of the point of diversion, the diversion section between the point of diversion and the point at which diverted water is returned to the stream, and the section downstream of the tailrace. [...] Salmonid abundance and species composition may change in the diversion reach as a result of changes in the movement of sediment and fish food, changes in flow and salmonid habitat availability, and due to changes in temperature and oxygenation. [...] However, without estimates of the reduction in salmonid abundance as a result of the operation of the facility, and gains in salmonid abundance as a result of the compensation habitat, we could not reach definitive conclusions regarding no net loss in salmonid abundance. [...] Coefficient of variation: The ratio of the standard deviation to the mean, which characterizes the degree of variability in relation to the mean value of the population. [...] The increased number of run-of-river facilities constructed and being considered in BC in recent years, along with uncertainty in the magnitude of potential impacts on salmonids, led three entities to jointly commission and fund an independent review of run-of-river hydroelectric projects in BC: the Clean Energy Association of British Columbia (CEBC), the Gordon and Betty Moore Foundation, and BC’