The long wait for water has finally come to an end following the discharge of surplus water from Mettur reservoir into the river Cauvery. The Mettur dam, with a capacity of 120 ft, attained the full reservoir level for the 39th time this year in its 85-year history following continuously heavy discharge from the Kabini and Krishnaraja Sagar reservoirs in neighbouring Karnataka.
It is indeed a real feast to the eyes to see the Cauvery brimming with water and farmers are looking forward for a good Samba crop. However, we cannot be assured of the same situation every time given the the climate experts’ prediction of fewer rainy days in future. Ironically, Tamil Nadu continues to reel under severe water crisis even during the years of a good monsoon. This implies that there are certain crucial factors beyond climate change which either go unnoticed or fail to be recognised as pivotal in explaining the persistent water woes of the State.
Whenever there is a heavy discharge of water from the dams following a good monsoon, incidents of floodwaters being released into the sea and water breaches on the banks of major rivers and canals are reported. The Mettur water inflow into the Grand Anicut Canal had to be stopped a few days back, following a breach on its banks. Similarly, in 2013 farmers of the delta region had voiced concern over the heavy water discharge from the Mettur dam which resulted in flash floods downstream and caused wide breaches in the banks of Kollidam and Lower Anicut. According to an estimate, about 17 tmcft of floodwater was let out into the sea during August 4-8 , 2013, despite people reportedly facing drinking water scarcity in the Cauvery delta, especially in the tail-end areas.
This was a huge agricultural loss given that one tmcft of water is valued at ₹50 crore in paddy production terms. When the problem of water scarcity persists amidst plenty, then the real culprit is poor management of water resources and not climate change. It is high time that we stop blaming climate change alone for water shortages and start focussing on managing water.
Steps to check water loss
The Mettur dam is one of the largest dams in the country and according to the Cauvery Water Disputes Tribunal and the Supreme Court, it irrigates approximately 24.71 lakh hectares in Salem, Namakkal, Erode, Karur, Tiruchi, Thanjavur, Ariyalur, Perambalur, Tiruvarur, Nagapattinam, Pudukottai and Cuddalore districts.
Around 700 water bodies along the Cauvery basin get replenished by its waters. Tamil Nadu is home to about 41,127 tanks. However, with the decline in the community maintenance of small water bodies, a large number of these tanks are encroached, silted up resulting in the choking of supply and distribution channels. Consequently, the area under tank irrigation declined gradually from about 9.36 lakh hectares in 1960-61 to 4.38 lakh hectares in 2015-16.
Heavy siltation and weed growth all along the irrigation channels especially between Mettur Dam and Grand Anicut has also resulted in the decline in area under canal irrigation from 7.88 lakh hectares in 1950-51 to 6.72 lakh hectares to in 2015-16. By regularly de-silting and dredging the tanks, the surplus water from Mettur dam can not only be stored to full capacity in tanks and canals but can also reach the tail-end areas without delay.
To save every drop of the floodwater that is now being wasted, construction of check dams and anicuts across both Cauvery and Kollidam rivers, is the need of the hour. Check dams are a necessity in Nagapattinam, Thiruvarur and Thanjavur districts where discharge of floodwater to sea is significant. Check dams help preserve surface water for use both during and after the monsoon. They also help in groundwater recharge which in turn helps in raising the water table in the area. Gujarat has saved water and improved its groundwater level considerably, due to the construction of check dams.
Besides, the Command Area Development Programme, which was launched during the 5th Five-Year Plan specifically to increase water use efficiency in canal command area, needs to be stepped up to improve the irrigation potential and optimisation of agricultural production and productivity through integrated and coordinated approach of efficient water management.
Water accountability
Besides investing in water management initiatives, immediate steps need to be taken to discourage farmers, especially in the tail-end areas where water availability is scarce, from growing water-guzzling crops. Micro irrigation is one of the tested options available. Field level studies in Tamil Nadu and elsewhere have proved that drip, sprinkler and system of rice intensification save about 50 per cent of water per acre, while increasing productivity substantially compared to conventional methods in water intensive crops such as paddy, sugarcane, banana and vegetable crops. The Swaminathan Committee report, More Crop and Income Per Drop of Water (2006) and The Economic Survey 2015-16 have also highlighted these options.
There is an urgent need to compute water requirements of different crops and introduce volumetric pricing of irrigation water on a large scale as advocated by the Vaidyanathan Committee Report on Pricing of Irrigation Water (1992).
There should not be any more delay in implementing water audit which would involve monitoring the water supply from the source to the end user and prevent leakage or theft. While farmers in certain districts of Tamil Nadu have urged the local administration to undertake water audit, in Maharashtra and Gujarat, it is already in place.
Need for a radical shift
Farmers need not always depend on the state government or the local bodies to manage water bodies. The Participatory Irrigation Development and Management approach needs to be popularised wherein farmers are directly involved in distributing water to users. Water Users’ Associations (WUAs) in Maharashtra have been successful not only in efficiency of water use but also in reducing operation and maintenance expenditures. In Andhra Pradesh too, WUAs manage, maintain and distribute water resources. Efforts need to be taken to institutionalise and strengthen community-based water management in Tamil Nadu as well.
Unless these corrective measures are taken on a war footing, the paradoxical situation of persistent floods and water scarcity will continue in Tamil Nadu. It is high time that we shift our focus from the supply side to the demand side management in order to increase water efficiency. Let us not forget that our existence, growth and development will be governed by the way we use and manage water in the times to come.
Narayanamoorthy is Senior Professor and Head, Department of Economics and Rural Development, Alagappa University, and Alli is Senior Assistant Professor in Economics, Department of Social Sciences, Vellore Institute of Technology