Storing rain water and recharging the groundwater table are the twin solutions to prevent drought
Chennai’s morning raga used to be the ringing of church bells, the call of the muezzin or the chant of suprabatham.
Not this year.
The resounding thud of the falling of underground water sump covers every morning is what characterises the city.
In practically every household and apartment complex, worried citizens check the sumps to see if they have at least a few inches of water.
Invariably, there is not even a trickle.
For a city that consumes anywhere between 800 to 850 million litres a day (MLD), coupled with the fact that it is dependent on monsoon and groundwater resources, the deficit precipitation over a fast-expanding megapolis (currently Chennai Metropolitan Area extends to around 880 square km), it is a daily struggle for the Chennai Metro Water Supply and Sewerage Board (CMWSSB), the city’s drinking water providing agency, to meet even half the demand.
A severe water crisis is once again upon the city.
Last year, when the world avidly tracked the looming threat of South Africa’s ‘Day Zero’ – of termination of piped water supply to residents due to severe water shortage – many in Chennai knew what that situation meant.
Only in January 2017, the then Chief Minister O Panneerselvam had declared the state of Tamil Nadu drought-hit, hardly fourteen-months after Chennai’s December deluge of 2015, when the city almost went under due to record rains, only to be followed by a year of deficit rainfall.
Experts say the current water crisis is not a bolt from the blue, but a familiar territory of cyclical weather phenomenon of good rainfall year followed by a year or two of deficit. Getting back to ancient system of interlinking yeris (lakes in Tamil) and better storage of a good monsoon are the only way forward, they add
“Tamil Nadu has always had a good monsoon year followed by one of poor rainfall. It is cyclical. In 1982-83, the entire nation suffered due to drought and in 1986-87 it was so terrible that there were reports of cattle falling dead to the ground in states like Gujarat and Rajasthan. Tamil Nadu also witnessed two drought years in the 1990s and it is no different in this decade,” points out Professor S Janakarajan, formerly with the Madras Institute of Development Studies (MIDS) and currently President, SACI Waters, Hyderabad.
“Connect the link between the two, instead of looking at normal and deficient years as independent of each other,” he says. “Once in two or three years we get very good rains. Put mechanisms in place to save every precious drop. We received about 2600 mm of rainfall in December 2015. We failed to save any, letting the water run off to the sea. We could have trapped at least 300 tmcft of that and tided over the drought years. The city needs one tmcft per month and about 12 tmcft for the entire year. The target should be to save at least 200 tmcft a year, in order to quench the city’s thirst,” he adds.
It’s also time to go back to basics, says Sekhar Raghavan of Rain Centre, popularly known as the Rain Man after popularising the rainwater harvesting movement in the city.
“Preserve the yeris (lakes). For centuries, each village had an abundance of small water bodies and if one filled up, the overflow reached the next tank in a gradual fashion. There are over 3000 yeris in Kancheepuram and Tiruvallur districts. However these are getting encroached upon by the building industry or they are turning into dumpyards. Take care of the water bodies by desilting them regularly,” he says.
“Instead of pushing for storm water drains, where the water runs off to the sea, focus on diverting every drop of rain water into the soil,” he adds. “If your groundwater table is stable, drought can be managed.”
Experts also say setting up additional reservoirs will not help the situation if the fundamentals of water conservation are not met.