m
m
m
m3/s

Formula

q = Cd × b × h2 × (2g (h1 - h2)) 1/2

Where,
q = Water Flow Rate
Cd = Discharge Constant
b = Width of the Weir
g = Gravity (9.81 m/s2)
h1, h2 = Head 1 and Head 2 on the Weir