Downstream migrating fish want to go with the flow, but hydropower infrastructure can block migration routes. Fish migration plays a crucial role in maintaining the health of aquatic ecosystems, as it facilitates the exchange of nutrients and genetic material between different habitats, so fish passage is important not just for fish populations but for whole river ecosystems.
Fish protection at hydropower plants has typically been to block turbines with fine screens and to route fish around the turbines through low-flow fishways. This approach can still delay fish migration and expose fish to predators, and screens themselves sometimes harm fish who become trapped against them. Additionally, many fish still enter turbines where they are subject to traumatic injuries or death. Additionally, screens are costly to install and to maintain, and they also reduce overall flow, thereby lowering a plant's generation capability. Safe through-turbine passage for fish is a solution that benefits everyone, environmentally and financially.
Natel's RHT design offers a truly fish-safe option, whereby numerous species can pass multiple dams consecutively, and owners do not have to pay to keep them out of their turbines.