Most hydro projects divert from 50 to 90 percent of the average river flow in order to generate power. The result is dewatered rivers, destroyed fisheries, degraded wildlife habitat, and lost recreational opportunities. They contributed to the decline of native salmon and steelhead in the Eel River to the point that these species are now considered threatened and endangered. Virtually every hydro project has had some negative impact on native fisheries. Wildlife Hydro diversions also impact wildlife species.
Large reservoirs created by dams block the migration routes of deer.
Deer and other animals often drown in unfenced canals and reservoirs. Unwary eagles, hawks, and falcons risk electrocution when they roost on hydro project power lines. The impact of the sale and future operation of these projects on local tourism-based economies, sport angling, commercial fishing, and other recreational industries must be considered and mitigated. The vast amount of remaining water is owned and used by others downstream, who will be dependent on the new owners to meet water demands. Many local counties and water districts desire to acquire these projects to divert water for consumptive purposes, which may result in additional adverse changes in river flow regimes.