Identify the flow rate of the open channel by using the V-notch discharge formula. To calculate the flow rate, multiply discharge constant with 8/15. Multiply gravity (9.81 m/s^{2}) with 2 and find 1/2 times of it. Find tanθ by two, here θ is (V - Notch Angle). Identify 3/2 times of Head on the Weir. Multiply all the resultant values. V-notch weir flow equation can be simplified as 4.28 x C^{d} x tan (θ/2) (h + k) ^{3/2}.

Where,

Q = Flow Rate

C

θ = V - Notch Angle

g = Gravity Constant (9.81 m/s²)

h = Head on the Weir

V notch weir is also simply referred as "V-Notch". It is a plate placed on an open channel flow, which makes the water to flow over the "v" notch. V-Notch Weir Flow Equation aids to meter the flow of water by measuring the head of water over the v notch.