Weir

How do weirs help with the water?
A weir is a small barrier built across a stream or river to raise the water level slightly on the upstream side; essentially a small-scale dam. Weirs ...
What is end contraction of a sharp crested weir?
An end contraction is when the length of the weir (L) is less than the width of the Channel and a nappe contracts either one or both sides of the weir...