Weir

A weir is a barrier built across a river or stream to control water flow and measure water levels. Typically made of concrete or similar materials, it causes water to flow over its top in a predictable way. This allows engineers and scientists to monitor water volume, manage flood risks, and divert water for irrigation or other uses. Weirs are also used in hydroelectric projects to regulate water flow for energy generation. Essentially, they help manage and observe water behavior in natural or engineered waterways efficiently and reliably.