Final Project: A water treatment facility has an impoundment, or pond area whose discharge is
controlled upstream by a vertical sluice gate with a contraction coefficient of Cc = XXXXXXXXXXThe water level
in the pond and the discharge pass over a sharp-crested weir at the downstream end. The facility lies on
a constant slope of XXXXXXXXXXft/ft. The channel material is concrete throughout the gate, pond and weir
channels. The maximum rate of discharge, Q = 1000 cfs. The water level on the upstream face of the
gate cannot exceed 11.5 ft or it will risk overtopping the gate structure. All channels and the pond have
approximate vertical sidewalls. The bottom of the “gate” section of channel is elevated by 2 ft above
the pond. The weir height, P = 6 ft. Assume that the length of sections 2 and 5 are relatively negligible.
Flow over the weir is computed using the simplified weir equation, Q = CLH3/2, where the discharge
coefficient, C = 3.4. H is the depth over the weir. Graduate students should use the total head (depth
and velocity head) for H. Undergradutes can use the water surface elevation or total head.
Energy losses in the system are estimated as follows.
• Loss at gate. K = 0.1
• Expansion losses into the pond, Kexp = 0.3 of the velocity head differential (V22- V32)/2g where V2
is the velocity in the 22 ft wide channel just upstream of entrance to the pond and V3 is the
velocity at the upstream end of the pond.
• Contraction loss at the approach to the weir, Kcontraction = 0.5 of the velocity head V52/2g where V5
is the velocity upstream of the weir.
Determine the height of the gate (Yg) at maximum discharge and identify the depths at locations 1 – 5.