1. CASE: HADRAMAWT IMPROVED TRADITIONAL ENGINEERING 6.6

2. Rainfall isohyets WADI HADRAMAWT YEMEN

3. Hadramawt: special characteristics Extremely low rainfall (50 mm/year) Very irregular and often heavy floods Special efforts to avoid that large floods destroy command area and residential area) much attention for spillways( Groundwater and hence recharge is important

4. MANY LARGE FARMER-BUILT STRUCTURES IN HADRAMAWT

5. Water Master In many systems the traditional structures have been improved through a mix of modern and traditional techniques Al Powirigat Traditional Dyke

6. Special structures Diversion structures Bunds and dykes Traditional abutments Spillways Recharge bunds Command area structures Water distribution structures Field to field overflow structures Low flow field intakes

7. DIVERSION STRUCTURES Bunds and dykes Traditional abutments Spillways Recharge bunds

8. Traditional dyke at Hadramaut

9. Traditional diversion dyke – at angle with the flow of the river

10. TRADITIONAL DYKE: SPILLWAY/ OVERFLOW

11. AL ROMALYA TRADITIONAL WEIR REINFORCED WITH CONCRETE SPILLWAY WITH STEPPED STONES

12. TRADITIONAL ABUTMENT BREACH-ABLE EARTHEN BUND TO BREAK IN HIGH FLOODS AND RELEASE FLOOD WATER INTO THE RIVER FLOOD CHANNEL INTAKE

13. TRADITIONAL ABUTMENT

14. LIME MORTAR STRUCTURES

15. TRADITIONAL INTAKE IN HADRAMUAT

16. MOZA SIBHAM DYKE REINFORCED WITH TRADITIONAL ABUTTMENTS

17. MODERN ABUTMENT FOLLOWING TRADITIONAL DESIGN

18. COMBINED GABION SPILLWAY WITH TRADITIONAL ABUTTMENT

19. GABION SPILLWAY

20. Gabion spillway and traditional intake at gar- Sudan area (at wadi Dowan) Hadramawt

21. TRADITIONAL LOW RECHARGE WEIR TO SLOW DOWN AND SPREAD FLOODS

22. COMMAND AREA STRUCTURES Water distribution structures Field to field flow structures Low flow field intakes

23. WATER DISTRIBUTION: WATER IS DIVIDED PROPORTIONALLY IN SMALL CHANNELS

24. WATER DISTRIBUTION: GATES USED ON SOME OF THE SMALL CHANNELS TO CLOSE SUPPLIES AFTER AREA IS SERVED

25. FIELD OVERFLOW STRUCTURE

26. FIELD TO FIELD FLOW STRUCTURES (SPILLWAY)

27. FIELD OUTLET STRUCTURE

28. FIELD TO FIELD FLOW STRUCTURE (INLET OR OUTLET

29. UNDERFLOW STRUCTURE TO CAPTURE VERY SMALL FLOWS

30. FIELD SYPHON FOR FIELDS HIGH ABUTMENT