WATER CONTROL STRUCTURES

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WATER CONTROL STRUCTURES

• Erosion cant be always be controlled with
  vegetation and channel shape
• Reduce the channel slope between structures.
• Construct the structures to control the erosive
  energy at the drop.

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original channel slope
Drop Structures
new channel slope
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DROP STRUCTURE
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Straight Drop Spillway
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CHUTE STRUCTURE
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Chute Structure
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PIPE STRUCTURE
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Guide to Control Structure Selection
TOTAL DROP (FEET)
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100
0
FLOW RATE (CFS)
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Weir Flow
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WEIR FLOW EQUATION
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Drop Inlet Pipe Spillway
h
D
L
12
Hood Inlet Pipe Spillway
h
13
PIPE FLOW EQUATION
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Wood Drop Structure
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Gabion Drop Structure
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Chute Spillway
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Chute Drop Structure
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Propped Outlet and Plunge Pool Energy Dissipation
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Apron Type Stilling BasinEnergy Dissipation
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Impact Basin Energy Dissipation
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Weir Flow Calculations

• Given Weir Length 12 feet
• Weir Head 2 feet
• Find the Flow Capacity of this structure.

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Weir Flow Calculations

• Given Required Flow Capacity 120 CFS
• Weir Length 12 feet
• What Weir Head would be required?

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Weir Flow Calculations

• Given Weir Capacity 80 CFS
• Weir Head 1.5 feet
• What Weir Length is required?

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Pipe Flow Calculations

• Given a smooth steel pipe with a diameter of 12
  inches
• Available Pipe Head of 15 feet
• What is the capacity of this structure?

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Pipe Flow Calculations

• Given a required flow rate of 40 CFS
• Given a corrugated metal pipe with a diameter of
  21 inches.
• What pipe head would be required?

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Pipe Flow Calculations

• Given a required flow rate of 30 CFS
• Available pipe head 20 feet
• What diameter corrugated metal pipe would be
  required?
• What diameter smooth pipe would be required?