Q = 4.28 Ce tan (θ/2) (H + k)5/2 [in U.S. Units]
Head H on the weir, in m [or ft]
Width B of the channel, in m [or ft]
Side width b, in m [or ft]
Angle θ in radians
Ce and k are function only of θ (in degrees)
Discharge Q in L/s [or cfs]
For a fully contracted V-notch weir: H/B ≤ 0.2
Partially contracted 90° V-notch weir calculator
See USBR Manual for general methodology
Warning: Ratio b/H = 0 < 2. Ratio H/B = 0 ≤ 0.2. Weir is fully contracted.
Discharge Q : 0
Your request was processed at 03:33:21 am on October 29th, 2020 [
201029 03:33:21 ].