Low water use efficiency in irrigation projects in Inida

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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".

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6 Answers

  1. I think a it of prioritization is called for. I'd say the first would be lining of canals as much water is lost in seepage. I'm not so sure what you mean by 'encourage ground water usage' - I mean they prefer that already and ground water tables are falling alarmingly due to that. 2nd priority should be avoiding evaporation loss - perhaps a green cover around the canals in terms of trees would be a medium term solution - and that would also add to the environment. In terms of weeds removal, that is mainly due to stagnant or slow water flow as these are man made so we have devise ways to make the canals flow faster.

    1 Comment

    1. Hi Anuradha, Greetings from Jaipur. I am giving my comments point wise. (1 ) There is certain limit upto which seepage losses are permissible. If the seepage losses are much higher than the permissible, in certain portion of canal, then that portion should be lined. In my paper under consideration ( available as attachment , i have measured seepage losses in some portions of canal and canal lining was done in the portions of canal having excessive seepage losses) Even the lined canals have some seepage losses and there is some permissible limit for seepage losses in lined canal. Ground water levels as rule does not fall in areas irrigated by surface / canal water. (2 ) There is very little evaporation loss from canals and it is negligible. As such no measures are required to reduce it ( 3) There are many reasons of weed problem in canals, one may be due to slow movement of water in canal. But in Chambal Project canals in Rajasthan, it is due to the reason that the canal passes through the CB tank lake in initial portion of canal and CB tank lake has weed problem. The clear water increases weed growth, but weed growth is difficult in canal water containing silt. However every possible measure is being taken in chambal canals to reduce weed growth.

  2. Yogesh Ji, we [ Team of scientists with Dr.Kaiser Jamil] from Indian Institute of Chemical technology-CSIR-Labs] developed a technology which is very safe to the environment in controlling weeds and its been applied in many parts of India,the state of A.P,U.P, other parts in India,and submerged weeds like Hydrilla are also controlled by using pathogenic fungi and weevils.As you said it is a bit difficult to control in long river beds,but it is not impossible,the first thing is to use ponds for the rearing or multiplication of weevils/insects from early summer and keep the population ready-then alternatively use two bio-control agents which is more effective,the second thing is to control the weed infestation use the same system at river system by blocking the weed mats against the flow and treat them with bio-control agents,well we need to study the favorable conditions before the inoculation trials..it woks.Though the biological control is a bit slow,once it clicks the agents keep checking the weed growth.Now we are retired from CSIR,the technology we developed remains...you are most well come foe any further information.

  3. Hi Rajesh, Greetings from Jaipur. The low to very low water use efficiency in India, is pathetic and unreasonable. There seems to be little inclination of government departments, ministries, NGO and individuals involved in water sector, to take suitable, proper, practical, research oriented decisions to improve water use efficiency in irrigation projects. They have not made scientific diagnostic analysis, why the water use efficiency is low nor how the other counties are continuously increasing water use efficiency. They do not wish to take note of the work and efforts being done in this direction by others. Therefore first thing is that the governments may take initiatives to make their will strong in this direction and direct their ministries & departments to prepare a time bound result oriented action plan to increase this low water use efficiency.

  4. Dear yogesh sir,increasing water use efficiency in irrigation project in india is the mandatory reqirements.we can impove water use efficiency from minimum water evaporation , proper water roots , proper flow rate and optimum utilize of water.

    1 Comment

  5. The flow of the irrigation channels,and other water bodies are fully or partially covered by the aquatic weeds[ floating/submerged] During rabbi season the the water level is getting reduced due to the evaporation/transpiration of aquatic particularly the the water hyacinth which occupy the maximum water surface.Water hyacinth grows very fast in summer due to favorable condition and radiation which supports the luxurious growth of the weed.Chemical control is not advisable,as the the fauna and flora are the indirect target. Biological control is advisable to control the weed infestation,with out any pollution.Biological control is safe to environment and will not cause any side effects as it targets only the specific weeds-there is technology well documented by many authors and its being implemented in many tropical and sub tropical countries in the weed infested ares.Though the technology is available in a couple of research organization its not properly utilized by the Dept of irrigation in India.Biological control is involved by the application of specific insects[weevils and microorganisms] in a favorable conditions to multiply and feed on the targeted weed/pest.Their life cycle is completed only on the host plant,hence this technology is very safe to apply,to reduce the aquatic weed contamination and save the water loss in irrigation channels in farming operation,interested parties are welcome for discussions.

    1 Comment

    1. Hi Rajgopal, Greetings from Jaipur. You are very much correct. I have gone through the literature for biological control of weeds and also how to prevent the aquatic weed problem. The first thing is that the source of aquatic weeds be identified and treated. In Chambal Project canals in Rajasthan we have this problem. The Bye passing of old tanks in the canals has been done / being done. The uprooting of weeds from bed of canals is also being done regularly. Weeds develop in clear water. Biological treatment in canals in hundreds of miles may not be very much practicable. It may more suitable in lakes and reservoirs.

  6. Hi Yogesh. Improving both on- and off-farm water use efficiencies has been the principal focus of nearly $3 billion in investment in Australia's Murray Darling Basin. The work is continuing at full pace at present. We have focussed on improving irrigation district supply efficiencies through preparing, with irrigators, 30-40 year irrigation district plans that focus on infrastructure and water supply needs for the future, followed by a water loss 'hot spots' assessments using mainly EM surveys, then making fact based and logical decisions on best use of available funds for minimising supply channel losses. We have seen irrigation supply efficiency improvements of 20-25% as a result of the approaches being taken, with average supply channel efficiencies improving from around 60-70% up to often 90% depending on the technology selected. Decisions on future water supply availability have also taken account of climate change forecasting of potential rainfall changes in the area. On the basis that it is not much using improving supply channel efficiency if farms continue to use water inefficiently, on-farm projects have been converting many flood irrigation layouts to various types of pressurised systems, or to laser levelling of improved flood irrigation techniques (which is more suitable for some of the very large cropping areas we have here in Australia). This has been very popular with farmers, even though a minimum of 50% of the water savings from each farm have to be shared with the government for use in environmental watering and restoration. Happy to share my experiences with running this program at IWW if we get the chance. Regards. Richard McLoughin.

    2 Comments

    1. Hi Richard, Greetings from Jaipur - Rajasthan- India. In Australia you have improved the canal systems to a greater extent. But a lot is to be done In India to improve water supply channel efficiencies particularly by improved planning, design, construction procedures and maintenance. The water courses (field channels) are to be constructed by farmers themselves as per their own design, resources. In most of the cases field channels have not been constructed in full length, due to so many social, political, local and financial reasons. Therefore full proposed irrigated area is not covered by the field channels. Cropping pattern while designing the canals is never implemented nor the canals are improved as per the cropping pattern followed by the farmers. However I am sure participants in India Water week 2015will learn so many things from your experience in Australia. Thanks again.

    2. Hi Yogesh, Improving water use efficiency needs collective action on all the domains of irrigated agriculture. may be it is engineering aspects, crop production, irrigation application or water distribution .. key to move forward is continual improvement in all sectors of water use in command area. Capacity building of water users is undoubtedly needs to be attended on larger context.