Fish Ladder

fish · engineering · rivers

Helps migrating fish. Fish ladders are structures built around dams and waterfalls to give salmon, trout, and other fish a way to swim upstream to where they were born. Without them, dams would completely block fish from reaching their spawning grounds.

Works like stairs. Most fish ladders have a series of small steps or pools that gradually get higher, so fish can jump or swim up one small level at a time instead of trying to tackle a huge waterfall all at once.

Tracks fish movement. Scientists use viewing windows and cameras in fish ladders to count and study which species are migrating, helping them understand how healthy fish populations are doing.

Different designs work. Fish ladders come in many styles, from traditional stepped pools to modern fish cannons that suction fish up and over barriers, each designed for different types of rivers and fish.

Restores nature. By letting fish complete their natural migration cycles, fish ladders help keep wild fish populations strong and prevent species from disappearing from rivers.