Book 19, Question 99
What Is a Weir?
A weir is a low wall built across a river to raise the water level a little or to measure the flow! Water spills over the top. It is a small, simple dam.
More fun facts
- A weir is a structure people build in a stream.
- Scientists use weirs to measure how much water flows.
- A weir in Yellowstone also helps track changes in nearby hot spring activity.
- Long ago, people built stone fish weirs to trap fish.
- An underwater stone fish weir in Southeast Alaska may be at least 11,100 years old, maybe the oldest ever found.
Sources: U.S. Geological Survey, NOAA Ocean Exploration
Questions kids ask
How old is the oldest fish weir?
An underwater stone fish weir in Southeast Alaska may be at least 11,100 years old.