ABSTRACT
Fish locks and fish elevators have not been grouped together because of any resemblance in their method of operation, but because they both represent alternatives to conventional fishways for passing fish over dams. A fish lock is defined as a device to raise fish over dams by filling with water a chamber, which the fish have entered at tailwater level or from a short fishway, until the water surface in it reaches or comes sufficiently close to forebay level to permit the fish to swim into the forebay or reservoir above the dam. It is similar to a navigation lock, fish have been known to pass upstream through navigation locks on many occasions. A fish elevator is defined as any mechanical means of transporting fish upstream over a dam, such as tanks on rails, tank trucks and buckets hung on a cable. There has been no information published on the costs of the fish lock installations in modern dams.
