Monsoon swings: Central and south India see surplus rain, nine states face deficit

New Delhi: The southwest monsoon began with an 11% rainfall deficiency in June and has been patchy across India. While central and southern regions have experienced surplus rains, the northwest and eastern parts of the country continue to suffer from deficits, triggering concerns about water levels in reservoirs.

After starting with a 13% rainfall deficit in June, central India has seen a dramatic shift, recording 21% above-normal precipitation. Southern India has also seen 24% more rainfall than usual, resulting in flooding. 

On 8 July, Mumbai received over 300 mm of rain in just six hours, the second-highest on record after the infamous 944 mm deluge on 26 July, 2005. Last week, Kerala's Wayanad district was hit by severe landslides, resulting in 308 casualties—the worst disaster since the 2008 floods.

The national rainfall deficiency has turned to a 7% surplus as of 5 August, largely due to the transition from the El Niño-Southern Oscillation to La Niña. While this shift has brought relief to some regions, the continued imbalance between excess and deficient areas poses ongoing challenges for water management and agriculture.

Northwest and east and northeast India regions continue to grapple with rain deficiencies, recording 8% and 13% less rainfall than normal, respectively, since the start of the monsoon season. June saw even greater deficits, with 33% below-normal rainfall in the northwest and 13% below-normal in the east and northeast. 

The India Meteorological Department (IMD) forecasts below-normal rainfall for these areas in the second half of the monsoon season.

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While 12 states have so far received excess rain since June 1; nine states in east, northeast and northwestern regions, including Jharkhand, Bihar, Uttar Pradesh, Punjab and Haryana, top kharif crops producers, are still facing rain deficiency, which is likely to continue, as per the met department.

India recorded 9% more rainfall than normal last month. However, July rainfall in northwest regions was 14.3% below normal. East and northeast India saw 23.3% deficient rains with Punjab, Haryana, Chandigarh, adjoining Himachal Pradesh, Jammu and Kashmir, Bihar, Jharkhand, east Uttar Pradesh, Gangetic West Bengal, and Odisha bearing the brunt.

Despite the surplus rain replenishing many water reservoirs, storage deficiencies persist in Punjab, Haryana, Bihar, and West Bengal. 

The live storage in 150 major reservoirs across India is 94% of what it was at this time last year and 107% of the 10-year average. 

The 10 reservoirs, including those in Himachal Pradesh, Punjab, and Rajasthan, are at 33% of their total live storage capacity of 19.663 billion cubic meters (BCM). This is a significant drop from 76% during the same period last year and slightly below the 10-year average of 53%

The 23 reservoirs in the east have a storage of 6.989 BCM, which is 34% of their total capacity of 20.430 BCM. This is an improvement from 31% last year but still below the 10-year average of 39%.

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