Module 2 (part 2)

1. Module 2 (part 2) Improving Diversion Works John Ratsey [john.ratsey@ntlworld.com]

2. 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

3. 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

4. Obar Fareed (Wadi Tuban) Spillway Head regulator Armoured head of intake

5. Obar Al Sadain – Wadi Tuban Head regulator Spillway Bed bar Armoured head of intake

6. 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)

7. 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

8. 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

9. Skimming weir Skimming weir constructed in front of head regulator. However, water is needed for flushing

10. Sediment in canal Gravel in canal reduced, but not avoided

11. The end of module 2 Thank you