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Abstract

A variety of electrified fish barriers are suitable for diverting fish from protected structures, e.g. pump intakes. Most take the form of linear curtain arrays (i.e. arrays of fixedly spaced-apart vertical elements). Many are characterized by the use of three or more pulsed driving signals of different voltages. This results in an electrical field pattern that extends broadside of the array, permitting fish an opportunity to turn and swim away before reaching a dangerous field strength. One barrier advantageously integrates the electrodes with a physical control structure that can be used to equalize the through-barrier water flow along its length. Others employ sets of electrodes that are driven in staggered, time-multiplexed fashion so as to reduce peak power requirements. Barriers used to screen pump intakes on the sides of flowing waterways are desirably sized and placed so that the velocity of water flow through the barrier is one-half, or less, of the waterway bypass flow adjacent the barrier. Other barriers include electrodes with horizontal and vertical sections (i.e. 'U' shaped), while still others have electrodes that are driven at both ends. A variety of other details are also disclosed.

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