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This document outlines the design and improvement strategies for the Al Mossefiyah Canal intake structure, focusing on a curved gabion wall to regulate intake openings effectively. It assesses potential adjustments for downstream user considerations while detailing the economics of constructing flood-resistant structures. Practical improvements, such as sediment removal and flow management, are emphasized, including skimming weirs and weir crest raising. The challenges with trash management at Waqar weir are also discussed, highlighting future design recommendations to optimize hydraulic performance.
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Module 2 (part 2) Improving Diversion Works John Ratsey [john.ratsey@ntlworld.com]
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
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
Obar Fareed (Wadi Tuban) Spillway Head regulator Armoured head of intake
Obar Al Sadain – Wadi Tuban Head regulator Spillway Bed bar Armoured head of intake
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)
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
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
Skimming weir Skimming weir constructed in front of head regulator. However, water is needed for flushing
Sediment in canal Gravel in canal reduced, but not avoided
The end of module 2 Thank you