With Gate Controls, the gate equation (1) below is used when the water level is higher than the gate soffit level. When the water level is lower than the gate soffit level then the gate is analyzed as a weir with equation (2) below.

where

W = width of the gate

H = height of the gate

h = upstream height of water

g = acceleration due to gravity (9.81 m²/s)

Cc = coefficient of contraction, a default value of 0.61 is given and is suitable for a vertical gate

Cd = coefficient of discharge, for use in the weir equation (2), a default value of 0.544 is used

Gate: Specifications 

Coefficient of Contraction - Enter the coefficient of contraction of the gate.

Height - Enter the size of the gate.

Width - Enter the size of the gate.

Invert Level - Enter the invert level of the gate.