|Modern Water Control in Irrigation: Concept, Issues and Applications (WB, 1994, 116 p.)|
FRIENDLY-USER CONTROL STRUCTURES
1. IRAN: Guilan project. Long-crested weir on Fumen canal.
2. MEXICO: Composite cross-regulator. The radial gates are used for large flow adjustments whereas the side weirs compensate normal flow fluctuations.
3. DOMINICAN REPUBLIC: Yaque del Norte project. This Begemann counter-weight gate installed upstream of a drop structure provides nearly constant level and constant flow at farm offtakes.
4. INDONESIA: Kedung Ombo Project. Sidorejo Canal. This 13 km long canal is automatically operated under downstream control.
5. Control Center.
6. A composite regulator consisting of a side weir and a remotely-controlled slide gate.
MOROCCO Haouz Irrigation Project. Canal de Rocade under dynamic regulation.
7. PERU: La Joya Irrigation District. Flow divider on the main canal.
SOME STRUCTURES TO AVOID
8. CHO (Constant-Head Orifice) offtakes; Because of the relative complexity of operation.
9. Rominj gate: Because of the fluctuation of the flow rate with minor changes in the water levels of the supply canal. As shown here, sluice-gated cross-regulators combined with Rominj-gated offtakes is the worst of all combinations of structures from the hydraulic point of view.
FROM CONVENTIONAL TO INNOVATIVE DESIGN
10. Conventional design
11. Construction of long-crested weir
12. Modular distributor
The conventional gated structures were modified by replacing one or two slide-gates by long-crested weirs and replacing CHO gates at offtakes by fiberglass modular distributors.
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Cover photographs by Hervlusquellec and Hans Wolter