Low water use efficiency in irrigation projects in Inida
The water use efficiency in Irrigation Projects of India can be substantially increased if the construction of water courses ( field channels) is included in the cost and work programme of irrigation projects. The low water use efficiency can further be increased too much by taking into consideration the head loss at different canal structures constructed across the canal. The Indian Standard codes need their through revision for proper design of canals and taking into account proper practical values of coefficient of friction (Rugosity coefficient). I worked on Action Research Programme aided by USAID for Gudha irrigation Project Rajasthan. As per experience gained , while working on this project as Research Officer, following steps will help in increasing water use efficiency in Irrigation Projects.
1. L-section of a canal should be finalised on the basis of micro network survey and chak boundaries.
2. Pipes should not be used in any masonry structure across a canal i.e. in head regulator, road bridges, siphons, etc. Only slab type openings should be provided across the canal to avoid head loss in blockage of pipes by miscreants.
3. Lining should be provided in the canal in reaches of excessive seepage losses and dispersive soil.
4. Conjunctive use of canal and ground water should be encouraged by creating canal water scarcity and giving incentive for using ground water.
5. The water courses should be lined in a length of at least 30 m. in the head reach below the outlet and other filling reaches to avoid loss of head/water.
6. The coefficient of friction (rugosity coefficient) in canal design should be adopted after carefully considering all factors and performance of canals in the adjoining areas.
7. Cultivators should be educated to use water efficiently adopting modern methods of irrigation and to prevent wastage of water.
I invite the comments of peers for this vital subject of "How to increase water use efficiency in irrigation projects".