New Delhi: Even as the overall rain deficit across India stands at 7%, water storage in 91 major reservoirs across the country has increased to 73% of their capacity—higher than last year.
The storage capacity in these reservoirs, which are monitored by the Central Water Commission (CWC), has recorded a rise of 4 percentage points since 1 September, after an excess rainfall of 18% over the north-western states this week.
Out of these 91 reservoirs, as many as 50 have higher storage available than last year. Most of them are in the south peninsula and central India.
While the south peninsula has recorded excess rainfall of 4.8%, it has been below-normal for the other three regions, with east and north-east India facing the maximum deficit of 24%. The overall deficit for north-west India has been 3%, while it has decreased to 1.8 % below-normal for central India.
As a result, water levels in six reservoirs in Himachal Pradesh, Punjab and Rajasthan remain less than last year when they reached 80% of live storage capacity. The current storage stands at 72% of capacity, up from 69% in August.
“The rainfall has been deficient in north and eastern India, so reservoirs are expected to be lower than normal storage. But a key factor is that snowfall has also been low this year. The ground water use is also very large and unsustainable, as more water is getting used upstream, and demand is increasing which has decreased the river flow,” said Himanshu Thakkar of SANDRP (South Asia Network on Dams, Rivers and People.) SANDRP is an informal network of organisations working on issues related to rivers.
The storage available in 27 reservoirs in Gujarat and Maharashtra is 5 percentage points less than last year, which could impact irrigation of winter crops in the rabi season.
However, there has been a rise in water levels in reservoirs in the south. The current storage in as many as 31 reservoirs in Andhra Pradesh, Telangana, Karnataka, Kerala and Tamil Nadu was recorded at 82% of capacity, up from 32% last year.
In addition, both Krishna and Cauvery river basins recorded higher storage capacities, as compared to last year. While storage in Cauvery basin and neighbouring rivers is 85% of capacity, as compared to 30.5% in 2017, in Krishna basin this year’s storage stands at 80% of capacity as compared to 43% last year.
“Though higher storage would be useful for sowing of Rabi crops, in long-term, it is not a good sign, as reservoirs are getting filled up, even when the rainfall is just marginally high and much before the end of the monsoon season. There is huge catchment degradation happening, so rainfall is quickly converting into surface water, especially in the Cauvery basin,” said Thakkar.