Deficient monsoon rains in the last two years have depleted water levels in the country’s 91-odd reservoirs to alarmingly low levels, even as the monsoon rains are predicted to reach Kerala’s coast next week. Till last week, the water reserves had fallen to 17% of the installed capacity of the reservoirs, while 31% of that capacity was filled up with water at the same time last year. The 10-year average reserves level at this time of the year is 21% of reservoir capacity.
The depleted water storage has already impacted hydropower production, besides adversely impacting drinking water supply and agricultural operations. According to the agriculture ministry’s third advance estimate, the country’s foodgrain production in 2015-16 is pegged at 252.2 million tonnes (mt), compared with 252 mt in 2014-15. According to the ministry of water resources’ data, storage in the 91 reservoirs has declined to 26.81 billion cubic metres (bcm) against 49.11 bcm a year ago; the 10-year average at this point of time is 33.76 bcm.
The water level is the lowest in the 31 reservoirs in southern India and 27 in Gujarat and Maharashtra. In reservoirs in Andhra Pradesh, Telangana, Kerala and Tamil Nadu, the total live storage available was only 5.21 bcm, 10% of the capacity. In reservoirs in Gujarat and Maharashtra, the total live storage available is 3.90 bcm or 14% of the capacity.
The Central Water Commission (CWC) monitors storage status of the 91 reservoirs, of which 37 have hydropower utility. After two successive years of deficient monsoons (2014 and 2015), the IMD last month had predicted ‘above-normal’ rainfall this year at 106% of the benchmark long period average (LPA), with a model error of ±5%.
“There is a 94% probability that the southwest monsoon will be above-normal to excess. There is just 6% chance of the monsoon being poor,” LS Rathore, director general, IMD, said. He also predicted that rainfall during the monsoon months (June-September) would be well spread out. Experts say that a normal monsoon is expected to give a boost to agricultural production as the majority of farm lands are rainfed and boosts water reservoirs levels, leading to improvement in the supplies of drinking water and higher hydel power output.