In order to end the dispute over Cauvery river water, farmers in Tamil Nadu and Karnataka should concentrate on growing millets and pulses that require less water, said Mihir Shah, a water expert who was recently appointed as chairman, Committee to draft National Water Policy.
Speaking at the event ‘Interrogating Cauvery Calling’ in Chennai on Saturday (November 23), Shah, who is also a former member of the Planning Commission, said that planting trees near the river banks by Isha’s ‘Cauvery Calling’ project alone will not help revive Cauvery.
“Planting trees near the river can help, but it will be meaningless if destructive activities continue in the upper catchment or the river,” he said.
A study published in the journal ‘Scientific Reports’ in 2018 said the annual run-off generated from 55 major river basins in India are declining, he pointed out. “This is not due to lack of rainfall but the destructive economic activities in the catchment areas. If this continues, most of these rivers will dry up,” he added.
Trees should be planted in the ridges where the damage begins instead of the immediate vicinity of the river, he said.
“We need a comprehensive, location-specific, catchment management plan, following the ‘ridge-to-valley’ approach,” he said. The urgent need is to address the demand side, but ‘Cauvery Calling’ addresses the supply side, he added.
Effects of Green Revolution
Green Revolution is a major reason for the depletion of ground water, according to Shah.
“The revolution witnessed the emergence of more chemicals in agriculture. Farmers also received loans for digging borewells. Deep digging resulted in the depletion of groundwater level. Extraction of groundwater is the reason why India’s peninsular rivers are drying up,” he said.
Borewells are one of the major source of irrigation in the Cauvery basin. The river basin has 80% aquifers comprising crystalline hard rocks, which have low rates of natural recharge of groundwater. “These rocks are lowering water tables and river flows are depleting much quicker due to dewatering of shallow crystalline aquifers,” he said.
The groundwater assessment done in the Cauvery basin as on March 2017 shows that 384 blocks in the Cauvery region witnessed overexploitation of water. Also, about 75% of the basin shows one or the other of contaminants, like arsenic and nitrate, said Shah.
Millets to revive Cauvery
It is well-known that around 90% of Cauvery water is used for agriculture, mainly to grow water-consuming crops like rice and sugarcane.
“Most important step to revive the Cauvery and end the dispute is to introduce low-water requiring millets, pulses and oilseeds into public procurement. This will massively reduce the demand for groundwater,” said Shah.
These crops must be included in programs like Integrated Child Development Services (ICDS), mid-day meals schemes and in the public distribution system, he added.
“Already crops like ragi and jowar are being cultivated in Mandya, Chamrajnagar, Tumkur and Hassan in Karnataka and in Dharmapuri, Salem, Erode, Coimbatore and Dindigul districts of Tamil Nadu. Sesame, groundnut and red grams are also being the major crops in the river basin,” he said.
This kind of diverse cropping pattern will create a win-win situations like river rejuvenation, increase in farmers’ income, and improvement in soil health, water security, water quality and consumer health, added Shah.