The collective water stock in 123 reservoirs monitored by the Central Water Commission (CWC) is 56.72 billion cubic metres (BCM) as of June 25. This is 33% of the total capacity of all these dams, 171.09 BCM. The current stock is almost twice that of June 2019 (29.16 BCM), and also well above the ten-year average storage of all these dams (33.21 BCM). As many as 104 of the reservoirs hold water that is over 80% of what is normal for this period. This additional storage is now a buffer stock as the monsoon season enters July.
Last year’s rain helped
“The water reserves are in a healthy position this year mainly due to the excess rainfall that the country received last season. Besides, the monsoon withdrawal was also delayed,” said Rakesh Kumar Gupta, Member, Design and Research, at CWC. Last year, the country-wide rainfall was 110% of the Long Period Average. This surplus rain left dams at optimum capacity, forcing discharge many times during the monsoon.
Could the lockdown have had a role in the water accumulation? While it is true that the lockdown from March 25 through May saw very little human activity — especially in factories and industries that are the main consumers of power — there is no evidence to link this to the water situation. “The dams were in a good position since last monsoon. However, we cannot link the consumption (low or regular) with Covid-19 situation,” Gupta said.
At least 88 reservoirs have higher stocks as compared to June last year. In the Central region, the collective storage stood at 17.21 BCM against 9 BCM at this time last year. In the Western region, the stock is 12.13 BCM against 3.56 BCM last year. In the Southern region, reservoirs have stored 13.05 BCM, giving them double the reserves they had in June 2019. In the North, water reserves are at 7.23 BCM, up from was 6.87 BCM. In the East, the curren stock is 7.11 BCM as against 3.12 BCM last year.
Almost all river basins — Ganga, Indus, Narmada, Tapi, Mahi, Sabarmati, Cauvery, Krishna, Godavari, Mahanadi — have above-normal reserves whereas rivers in the South have normal water stocks.
The India Meteorological Department has forecast a normal monsoon. So, if there is good rainfall, both spatially and temporarily, the reservoir position will remain healthy through the season.
With most regions maintaining stocks between 25-40% of capacity in June itself, the season’s water reserves in major parts of the country should be largely well manageable. The country has received 22% rainfall above normal, as on June 26.
📣 Express Explained is now on Telegram. Click here to join our channel (@ieexplained) and stay updated with the latest
This article first appeared in the print edition on June 27, 2020 under the title ‘Healthy stock in reservoirs’
📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay updated with the latest headlines