Efficient Irrigation: Optimising water usage in irrigation is the need of the hour

Like the progression of Maslow’s hierarchy of needs from physiological, safety, love and belonging, esteem to self-actualisation, our perception of water in India has also grown after the Independence from “Roti, Ka­pada aur Makan”, to “Bijli, Sadak, Pani”, to “Avi­ralata, Nir­malta and Swacchhta”, to “Jal Shakti Abhiyan/Jal Jeevan Mission”. And now we have to orient ourselves to eco-friendly initiatives, sustainability and atmanirbharata in the amrit kal of our independent India. India is currently grappling with a low irrigation efficiency of ab­out 38 per cent. As such, improving water use efficiency (WUE) is critical to improving the performance and output of the irrigation sector. To this end, while the government is moving towar­ds making policy and regulatory changes, there is tremendous scope for improvement through the adoption of new methods and innovative techniques. The primal need for water has transitioned to the need for continuous flow of water and clean riverbanks, which is being supported by government programmes such as the Jal Shakti Abhiyan and Jal Jeevan Mis­sion. The ultimate stage in this hierarchy is the need for eco-friendly and efficient water systems, river rejuvenation and sustainability. As a result of this transition, the role of water in irrigation systems has become important, es­pecially since about 80 per cent of water consumption is for irrigation.

Therefore, the Ministry of Jal Shakti is wor­king towards improving the performance of the irrigation sector by setting up the National Bu­reau of Water Use Efficiency under the Na­tional Water Mission, for the promotion and re­gulation of WUE in the irrigation, industrial and domestic sectors. The Bureau has been established to accomplish the National Water Mission’s goal of increasing WUE by 20 per cent. Further, a task force has been constituted under the National Water Mission for the preparation of a framework to be implemented by the Bureau to increase WUE. The task force,  in turn, has set up a Sectoral Group on Irri­ga­tion, with officials involved in the management of water resources at the state and central levels, as well as experts from the field. It has been preparing a report clearly stating a set of recommendations. The group comprises offic­ers from the nodal ministry, that is, the Mini­stry of Jal Shakti; other ministries dealing with matters related to water use such as the Mini­stry of Agriculture and Farmers’ Welfare, the Ministry of Housing and Urban Affairs, and the Ministry of Environment Forest and Climate Change; representatives from state governments; and sector experts.

Water efficiency and productivity

The Sectoral Group has submitted its report and made specific recommendations. The government is likely to implement them shortly to achieve eco-friendly and efficient water systems, river rejuvenation, and sustainability during the amrit kal of India’s independence. Wa­ter efficiency is defined as the ratio of the water consumed by a crop relative to the water withdrawn from a source, while water productivity refers to the ratio of the total crop output to the amount of irrigation water applied or co­n­sumed. These parameters have been recorded to be low in India, for both types of irrigation – canal-based and pipe-based. In re­cent years, the government has introduced various programmes for increasing water efficiency and water productivity of irrigation.

Measures recommended for increased irrigation efficiency

Several policy and regulatory reforms have be­en recommended by the Sectoral Group, chair­ed by the chairman of the Godavari River Ma­na­ge­ment Board, for improving irrigation ef­ficiency. The current utilisable water is 1,133 billion cubic metres (bcm), which is less than 30 per cent of the annual precipitation of 4,000 bcm. The recommendations also in­clude improving the output parameters targeted under the National Water Policy, 2012, such as increasing water storage from the present value of 258 bcm to 450 bcm, as well as revi­ewing the existing water reservoirs and repairing, renovating and restoring them. To this end, the first census on water bodies has already been completed. Other important short-term me­asures recommended for pushing the efficiency levels are…

Regulatory measures

The appraisal and monitoring process of water resource projects requires much greater attention. The Central Water Commission has been recommended to revise the guidelines for the preparation of detailed project reports for irrigation projects, and to measure irrigation efficiency on a regular basis. A minimum project irrigation efficiency will need to be stipulated with a minimum benefit-cost ratio for techno-economic appraisal and investment clearance of such projects. Further, central assistance should be recommended for states that have adopted efficient irrigation systems. This could be prescribed under programmes such as the Pradhan Mantri Krishi Sinchayee Yojana and the Com­mand Area Development and Water Mana­ge­ment schemes. Further, the Extension Renova­tion and Modernisation Scheme should also focus on substantial improvement in irrigation efficiency. A few steps have been taken to implement these suggestions, such as the promotion of wa­ter regulatory authorities at the state level. States such as Andhra Pradesh, Jh­ar­khand, Ja­mmu & Kashmir, Gujarat and Aru­nachal Pra­desh have enacted laws for the creation of such authorities.

Conservation of water

Water needs to be conserved in strategic ways to improve efficiency in irrigation. Conveyance losses must be reduced by lining channels or by using closed conduits through piped irrigation distribution networks, and micro-irrigation. Other initiatives include reducing direct evaporation during irrigation by avoiding midday sprinkling; minimising foliar interception th­ro­ugh under-canopy, rather than overhead, sprinkling; reducing runoff and percolation losses due to over-irrigation; and reducing transpirati­on by weeds by keeping the inter-row strips dry and applying weed control measures wherever needed. States such as Rajasthan, Madhya Pradesh and Telangana have already adopted piped irrigation systems.

Enhancement of crop growth

Crop growth enhancement is determined by the water productivity of the biomass. The concept of “more crop per drop” needs to be ap­p­lied, based on specific agroclimatic regions and their cropping patterns. There are around 16 agroclimatic regions in India, which need to be ass­es­sed. To this end, Haryana has adopted crop sub­s­ti­tution. Further, farming of locally suitable cro­ps is being subsidised and incentivised by the government for all states. Other recommendations include sowing and harvesting at optimal times, use of optimal tillage to avoid excessive cultivation, use of appropriate insecticides, parasite and weed control, and organic/green­ farming, along with soil conservation for long-term sustainability. Monitoring of water table elevation would also help in avoiding progressive salinisation.

Meanwhile, demand management through technological tools such as supervisory control and data acquisition (SCADA) will also help in assessing weather conditions and the crop gr­owth stage. To this end, SCADA has been used in the Narayanpur Left Bank Canal Sys­tem, and an improvement in efficiency has be­en obser­ved from 23 per cent to 52 per cent.

Future goals

The adoption of long-term strategies would be necessary to achieve the desired WUE in irrigation in the future. Water benchmarking and au­diting are two of the important measures that need to be undertaken by states. Model terms of reference must be established in each state and union territory for this. This must be proposed for implementation, along with irrigation systems that utilise pressurised irrigation networks and micro-irrigation. Irrigation efficiency grants to states could also be provided by the Finance Commission.

Further, WUE improvement programmes must be initiated in all states. Many internatio­nal organisations and donor institutions such as the World Bank and the Asian Development Bank are eager to offer support and provide fun­ds for such efficiency development programmes to state governments. Moreover, the adoption of floating solar panels is another concept that needs to be explored for its sustainable footprint. They do not require the complex process of land acquisition, and can be set up in an area of 4 hectares. Moreover, evaporation losses are minimised to the extent of 35-40 per cent through this method.

Based on the presentation by a senior official of the Godavari River Management Board, Ministry of Jal Shakti, at a recent India Infrastructure conference