NEW DELHI: I saw no difference at all in the sweltering conditions in Delhi and hill stations like Ooty and Coorg,” rued Johnson D’Souza, 40, a Gurgaon-based multinational company employee who recently returned from a visit to his native Coorg and Ooty with his family to escape the Delhi scorcher.
“I have no memory of such an unprecedented heat and water crisis in my scenic native place. In Ooty, hotels and resorts don’t have fans and air-conditioning equipment, which made our trip more unpleasant,” he shared.
According to the Indian Meteorological Department (IMD), Ooty was at its hottest on April 30. It recorded 29.4°C, its highest maximum temperature since 1901. On April 29–30 in Kodagu, the maximum temperature was 38.6°C, with the minimum at 23.5°C.
“Such high temperatures and humidity are unbearable and may impact our tourism business,” said 65-year-old Jaiamma, who runs a homestay for tourists in Udagamandlam.
Drought conditions in Kerala this year broke a 40-year record; major reservoir levels plunged to a new low in the Cauvery basin, especially in Karnataka; and villagers are digging wells and tubewells to get some water in the Rayalaseema region of Andhra Pradesh.
Major cities such as Bengaluru, Chennai, Coimbatore, Hyderabad and dozens of smaller cities are facing severe drinking water shortages. Almost the whole of peninsular India is reeling under heat waves, with temperatures hovering around 40–44 °C.
In April, the IMD recorded the second highest minimum and maximum temperatures in peninsular India since 1901—25.8°C and 37.57°C, respectively.
“If dry spells continue, water levels in different reservoirs would plummet to an all-time low at the end of the month and result in large-scale labour migration to bigger cities, which are already water-stressed,” said Ramanjaneyulu G V of Centre of Sustainable Agriculture, Hyderabad.
Deficit Southwest monsoon
India received 70% of its annual rainfall through the Southwest monsoon between June and September. The emergence of the El Nino phenomenon weakened the monsoon. El Nino is the unusual warming of surface waters in the eastern Pacific Ocean, which is synonymous with the weakening of the southwest Indian monsoon. India witnessed a 5.6% deficit in the Southwest monsoon in 2023. It had a bigger impact in the Southern Peninsula, which clocked an overall deficit of 8% across five states.
The deficit situation gets worse if one takes a closer look. For instance, there was a 24% rainfall deficit in Karnataka, which resulted in severe drought in 195 talukas of 23 districts. A 33% rainfall deficit was reported during the Southwest monsoon in the Cauvery basin spread across Karnataka, Tamil Nadu and Kerala. It snowballed into a 51% shortfall in cumulative inflows to Karnataka’s four major reservoirs monitored by the Central Water Commission. Even Kerala, which is the gateway to the Southwest monsoon, received a 34% deficit.
The rainfall deficit was 46% in the Pennar basin across Karnataka and Andhra Pradesh. Adjoining Pennar and the Cauvery basin, other basins such as Lower Tungbhadra (-50%), Upper Krishna (-42%), Krishna Pennar (-86%), Upper Bhima (-74%) and Lower Bhima (-65%) also had severe deficit.
Deficit Northeast monsoon
To begin with, the onset of the Northeast monsoon got delayed in October, overstayed till the middle of January and concluded with a shortfall by over 13% in the Southern peninsula and an overall deficit of 8.5% across the country. The Northeast monsoon contributes mostly to Kerala, Tamil Nadu, Puducherry, parts of Karnataka and Rayalaseema. It was patchy, too. It recorded deficits of 29% and 38% in Rayalaseema and in Karnataka, respectively, but was surplus in Tamil Nadu (+4%) and Kerala (+27%).
Severe deficit pre-monsoon activities
The IMD recorded a huge deficit in pre-monsoon rainfall activities, which were important to arrest the plunging reservoir levels and bring down the temperatures. The rainfall during April 2024 over South Peninsular India (12.6 mm) was the fifth lowest since 1901 and second lowest since 2001.
According to the IMD, there was a deficit of 66–82% of pre-monsoon rainfall between March and the first week of May this year in all peninsular meteorological stations. In Rayalaseema, the deficit was 82%, followed by the Tamil Nadu region (-77%), South Interior Karnataka (-70%), Kerala (-66%) and Coastal Andhra Pradesh (-62%).
Plunging reservoir levels
The deficit of pre-monsoon rainfall led to a severe water crisis in April-May. According to the Central Water Commission's May 9 bulletin, in Karnataka's Krishnaraja Sagara (KR Sagar) and Kabini reservoirs, the live storage fell to a 30-year average low. KR Sagar had 10 TMC last year, which plunged to 7.2 TMC now.
Similarly, Kabini had 4.6 TMC average live storage last year. It's down to 3.7 TMC this year. The available live storage of Tamil Nadu's reservoirs, Mettur and Bhavanisagar, is also lower than their 30-year average.
“If pre-monsoon showers don't get activated in the coming days, water level in KR Sagar will fall to its lowest since its inception,” said Venkatesh R L, Chief Engineer, Irrigation (South) Zone at the Cauvery Neeravari Nigama.
The KR Sagar Dam reached its lowest level on June 13, 2013, at 62.80 feet. Its level as on May 9 was around 79 feet, compared to last year’s 85 feet. Both Karnataka and Tamil Nadu are left with water only for drinking and domestic use till the southwest monsoon sets in.
“Even if the Southwest monsoon is normal in June-July, because of acute moisture deficit in the soil due to the severe drought, there may not be enough runoff to the catchment of the Cauvery basin,” said K E S Mahesha, managing director of the Cauvery Neeravari Nigama.
Climate change
Experts attribute several climatic factors to the excessive heating of peninsular India, which include weakening of the land-ocean temperature gradient due to global warming. Globally as well, each month is setting a new all-time record. The last 10 months since June 2023 have been the hottest on record because of El Nino. The Indian Ocean has one of the world’s fastest-rising sea surface temperatures.
“There are several factors involved in the current peninsular drought, including the strengthening of El Nino, which contributed to the above normal temperatures coupled with a long spell of marine heat wave in the Indian Ocean,” said Dr Vimal Mishra, Professor, Civil Engineering and Earth Sciences, at Indian Institute of Technology, Gandhinagar.
“Climate change induced the late onset of a strong Southwest monsoon and the change of cropping pattern towards water-intensive paddy and cash crops like cotton,” said Ramanjaneyulu.