Abstract: A helical eel ramp spirals vertically with a plurality of turns and has a ramp surface with a ramp entrance on a bottom portion of the helical ramp, a ramp exit on a top portion of the helical ramp, a radial inner edge, and a radial outer edge. An outer barrier is connected along the radial outer edge of the helical and extends upward from the radial outer edge to retain liquid flow on the ramp surface. An inner barrier connected along the radial inner edge of the helical ramp also extends upward from the radial inner edge to retain liquid flow on the ramp surface. The ramp surface, outer barrier, and inner barrier define a channel configured to direct a liquid to flow from the ramp exit to the ramp entrance.

Abstract: An improved fish deterrent and guide, utilizing generally a paddlewheel (1) consisting of a central shaft (10) with vanes (12) to create a behavioral modifier. When paddlewheel (1) is rotated, the action of the vanes striking the water creates water particle motion (low frequency sound or infrasound), turbulence and current, as well as visual cues that fish avoid. The device is tunable for different fish species and life stages by adjustment of vane style, spacing, and paddlewheel rotation speed. The use of multiple behavioral deterrents creates a measure of reliability in the system. Another advantage is that this fish deterrent provides a continuous lead, which is more effective than typical point-source turbulence and sound generators. Typically, the paddlewheel fish deterrent and guide is positioned at the water surface across the intake to a power plant intake to deter surface oriented downstream migrating fish, and guide them to a bypass.