Cape Town in South Africa was possibly one of the earliest instances of a major metropolis to get associated with Day Zero. Around late 2017 the first reference to kickstarting a Day Zero plan started to be discussed as a series of years with poor rainfall from 2015 led to a situation which led to a restriction of 100 litres per day by June 2017. By early 1st January 2018 the city declared Level 6 water restrictions of 87 litres per person per day. In February 2018, the City increased restrictions to Level 6B limiting usage to 50 litres per person per day. At this point of time Level 7 restriction or Day Zero was looming large with the water supplies expected to be cut off through the municipal sources as dams reach the level of 13.5% of their total capacity.
Fortunately good winter rains during the year 2018 meant the Day Zero did not happen though restrictions continued until late September when the storage improved to about 70%. Closer home Chennai also went through similar circumstances during the year 2019 on the back of a poor spell of rains starting from 2016 Northeast Monsoon. Just like Cape Town the Chennai Zero Day also did not happen eventually with the government of the day making every possible effort to improve water availability including bringing water including water from Cauvery through Rail Wagons. A total of 159 trips were made between July and October 2019 transporting nearly 420 million litres of water from Jolarpet.
The last couple of months it is the turn of Bengaluru to stare at a water crisis leading to companies opting to go back to WFH as citizens spend most of their day time chasing water for their day to day needs. Cauvery to an extent is once again the saviour, though a large part of the metropolis is not connected to the Cauvery Drinking water scheme and depend on water tankers as their own sources run dry. As Summer starts to crank up the heat possibly the worst phase is likely to be ahead of Bengaluru before things pick up on the back of the return of much needed summer thunderstorms.
April is the hottest month for Bengaluru if one goes the mean max temperature data maintained by the Climate Research & Services of India Meteorological Department at Pune with May being the second hottest. So in a way the worst phase in terms of temperature is still to come for Bengaluru and the past experience of how 2016, the last time we had a very strong El Nino episode, show 2024 April could be abnormally warm as well. This is also corroborated by sub seasonal weather outlooks from ECMWF Ensembles which indicate the mean temperature for Bengaluru may be on an average 2 to 3°C above normal during most of April and the initial days of May.
If temperatures are expected to stay abnormally hot the weather models are not very enthusiastic about rains bringing in some much needed relief for Bengaluru during the month of April. Not only history is loaded against the probability of April Rains becoming a saviour for Bengaluru but sub seasonal weather models are also not indicating any positive rainfall anomaly to bring cheers to the citizens. Since 1901 two out of three years Bengaluru has recorded less than 50 mm during the month of April with nearly 1/3rd of the 123 years recording less than 20 mm indicating how heavily history is stacked against the prospects of Summer thunderstorms during the month of April.
While there could be some rains around 7th to 10th April the first active spell of rains which could make a difference in terms of the ground water crisis is not expected to kick start until late into April. The last couple of days and the early days of May is when we could possibly expect an active spell of summer thunderstorms for Bengaluru going by long term ensembles.
But as the noted poet Thiruvalluvar wrote Rain is capable of helping people when they need the most.
கெடுப்பதூஉம் கெட்டார்க்குச் சார்வாய்மற் றாங்கே
எடுப்பதூஉம் எல்லாம் மழை.
Rain holds the power of ruin.Rain also lifts up those it has ruined.
While we can always hope for the elixir of life to once again save us at the time of need it becomes very important to ensure not only we don’t waste water unnecessarily until then but we are also ready with Rainwater harvesting arrangements when the city starts to receive its spell of rains from Thunderstorms