Weir
Videos
A weir, or low-head dam is a barrier across the width of a body of water that alters the flow characteristics of water and usually results in a change in the height of the water level. Weirs are used
A weir on the Humber River near Cruikshank Park in Toronto, Ontario, Canada
A weir on the Yass River, New South Wales, Australia, directly upstream from a shared pedestrian-bicycle river crossing
A weir on the Tikkurilankoski rapids in Vantaa, Finland
The broad crested weir at the Thorp grist mill in Thorp, Washington, US
Fish ladder
Videos
A fish ladder, also known as a fishway, fish pass, fish steps or fish cannon, is a waterway structure on or around artificial and natural barriers that provides aquatic animals a "detour" to facilitat
Weir
…habitat are lost, and over time this can have a significant impact on fish populations. In many countries, it is now a legal requirement to build fish ladders into the design of a weir that ensure that fish can bypass the barriers and access upstream habitats. Unlike dams, weirs do not usually prevent downstream…
Pool-and-weir fish ladder at Bonneville Dam on the Columbia River
Salmon climbing a ladder on Issaquah Creek, Washington
Cameras or other types of devices can be used to count fish as they pass through the ladder.
Denil Fishway on Salmon Creek, Montana