Module 2 (part 2)

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Module 2 (part 2)

• Improving Diversion Works

John Ratsey john.ratsey_at_ntlworld.com
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Initial layout for Al Mossefiyah Intake
Another canal
Curved gabion wall
Width 100m
Wadi flow
Gabion wall
Gabion wall to restrict intake opening size
Al Mossefiyah canal
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Suggested layout for Al Mossefiyah Intake
Possible bed bar if acceptable to downstream users
Gabion wall designed as spillway
Intake structure with orifice
Gravel embankment to be constructed by farmers
Wadi bank
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Obar Fareed (Wadi Tuban)
Spillway
Head regulator
Armoured head of intake
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Obar Al Sadain Wadi Tuban
Head regulator
Spillway
Bed bar
Armoured head of intake
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Economics

• Building flood resistant structures can be
  expensive
• The benefits, from reduced maintenance work and
  improved crops, may be moderate
• Functional requirements may be changed after 25
  or 50 years (higher command levels, even fewer
  floods)

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Improvements to modern intakes

• Works to improve sediment removal
• Eg. skimming weir in front of intake
• Removal of divide wall
• Works to improve hydraulic performance and flow
  division
• Weir crest raising to restore command
• Works to help flow management

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Waqar weir
The trash floating down the wadi cannot turn over
the weir and goes straight to the intake.
Difficult to fix, but note for future designs
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Skimming weir
Skimming weir constructed in front of head
regulator. However, water is needed for flushing
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Sediment in canal
Gravel in canal reduced, but not avoided
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The end of module 2

• Thank you