Abstract: A fish diversion system for a penstock housing a hydroelectric turbine employs large area screens to shunt fish to a bypass conduit above the turbine. The screens are disposed generally lengthwise of the penstock and inclined upwardly at a shallow angle to maximize water flow velocity along the screens while minimizing the approach velocity normal to the screens. Fish and debris are thus swept along the screens rather than impinged on them. One embodiment uses two screens set end to end. The upstream screen can be tiltable for cleaning. A second embodiment uses a unitary elliptical screen in a cylindrical penstock. The bypass conduit is sized and positioned to minimize bypass water flow volume while maintaining sufficient volume and velocity to discharge fish from the upper portion of the penstock. A funnel-shaped bypass manifold connects the penstock to the bypass conduit.

Abstract: A fish diversion system for a penstock housing a hydroelectric turbine employs large area screens to shunt fish to a bypass conduit above the turbine. The screens are disposed generally lengthwise of the penstock and the upstream screen is inclined upwardly at a shallow angle to maximize water flow velocity along the upstream screen while minimizing the approach velocity normal to the screens. Fish and debris are thus swept along the screens rather than impinged on them. The bypass conduit is sized and positioned to minimize bypass water flow volume while maintaining sufficient volume and velocity to discharge fish from the upper portion of the penstock. The upstream screen can be tiltable for cleaning.