Bengaluru: The recurrence of severe drought in many parts of the country has prompted state governments to devise innovative water management techniques and the immediate success in some of them in states like Maharashtra and Karnataka has kindled a ray of hope. But there are also voices of caution.
Activists and experts said such schemes may not be sustainable in the long term and may damage the natural water percolation system.
Water conservationist Vijay Borade said Maharashtra's Jalyukt Shivar Abhiyan — launched in December 2014 — mainly involves deepening and widening of streams, canals and rivers and will have a long-term negative impact on the recharging of underground water and its quality.
"There is rock after a layer of soil, which is exposed after desilting and deepening activities. If the rock is exposed, how will water percolation happen? Water will just run off. Naturally, soil holds water and helps in recharging the underground water table. Although we see water availability today due to the Abhiyan, underground water-levels will be depleted in the near future," Borade told IANS.
The removal of the soil layer also destroys natural filtration system, leading to water contamination.
Borade said the Maharashtra government did not address his complaints and suggestions on the Jalyukt Shivar Abhiyan.
Borade, a winner of the Maharashtra government's Krishi Bhushan Award, said due attention should be given to soil conservation rather than just focusing on water conservation.
"We lose 15 tonnes of soil per acre annually as it washes away with running water. Unless we check soil erosion, water infiltration will not happen. One should not be worried of rains, they will come. One should think of soil conservation, which will take care of water conservation," he contended.
Interestingly, Borade has a reason to back his claims. Kadwanchi village in the heart of Maharashtra's drought-prone Marathwada region, is said to have never faced water scarcity in the last 10 years due to an effective watershed management plan.
Borade also lauded the efforts of the Sri Sri Institute of Agricultural Sciences and Technology Trust (SSIAST), Bengaluru, in taking up the rejuvenation of 30 rivers in Karnataka, Maharashtra and Tamil Nadu by reviving natural water resources, terming this a sustainable effort.
Geo-hydrologist and SSIAST trustee Y Lingaraju said watersheds are developed at various locations for effective percolation and sustained water flow to the river basin.
"For the rejuvenation of Kumudavathi river near Bengaluru, we are developing watersheds at 18 locations. This includes construction of boulder barriers on canals and streams to promote soil moisture and water percolation, construction of recharge wells, big tanks and injection pipes of up to 500 feet," Lingaraju, a former director of the Karnataka State Remote Sensing and Application Centre.
SSIAST's efforts have borne fruits as Makankuppe, Tavarekere, Mondigere and Teppadabeguru villages on the outskirts of Bengaluru have witnessed improved water availability in tanks and lakes during the last two summers after watershed techniques were implemented, Lingaraju claimed.
Meanwhile, Shakeel Ahmed, Chief Scientist at Hyderabad's National Geophysical Research Institute, said the Telangana government didn't carry out any scientific studies before launching its Kakatiya scheme in March 2015.
"Initial results seem good but we are not sure of long-term impact since no scientific study has been carried out. It could be no longer sustainable if the water percolation system is disturbed. If aquifer mapping is done, the government will be in a position to implement the scheme in a scientific and effective way," Ahmed told IANS.
The aquifer mapping could be done through helicopter-mounted optics-based technology, he suggested.
Updated Date: May 17, 2017 12:32 PM