Fishway - Vertical Slot

Vertical slot fishways consist of a concrete channel that bypasses an obstruction such as a weir. Vertical slot fishways are generally used on low to medium sized weirs up to 6 metres high, and depending on the length of the fishway, resting pools are incorporated to allow fish to rest as they move upstream.

The fishway channel consists of a series of interconnected pools separated by baffles, each with a vertical slot opening. These openings restrict the amount of water that can pass from one pool to another and so control water characteristics within the fishway. These characteristics, such as headloss (height difference between pools), water depth, velocity, and turbulence, affect the ability for fish to move upstream.

Vertical slot designs can be quite different depending on the target size classes of fish species. Standard vertical rectangular shaped slots, key-hole slots that have variable slot widths, and dual slots with both large and small widths have all been used successfully.

Many different types of vertical slot fishways in Australia have been proven to be effective with native fish.