This pass works by slowing the flow and increasing the depth of water through the pass; the angle of the slope for the fish to tackle is also lowered. Larger fish are then able to swim up the pass and make their way up, with smaller fish being able to rest behind the baffles before they jump over the next one.

The passes at Brightside and Steelbank have two flights of baffles (see schematic) with a resting pool in between them that allows fish to recover strength.