After a heady few years for Chennai in terms of weather and water, 2018 has some good news in store. Chennai city is said to have reached satisfactory levels of storage in its reservoirs, ranking the second best after the 2015 flooding. Close to 5 TMC of water has been recorded in Chembarambakkam’s reservoir, one of the city’s major sources of water. This means no water shortage and a healthy forecast for post-summer rains in June.
Very few cities depend on surface water potential, and Chennai is one of them. Coimbatore gets its water from Siruvani, Madurai from Mullaiperiyar and Vaigai, and Nagercoil from Mukkadal. Chennai's major reservoirs are Poondi, Chembarambakkam, Cholavaram and Redhills, which have been meeting the water needs of 1TMC for the entire city successfully so far. "If the monsoons fail," says Gandhi Mathi Nathan, a retired engineer of the Public Works Department, Chennai city, "we have the option of going to wellfields. There is no reason to worry at all."
This 2018, the kindness of the Rain God is showing. After a successful North East monsoon bringing the maximum rainfall to the city as opposed to other drought-ridden cities and districts, Chennai has fulfilled its promises of reducing water shortage.
For instance, in November 2017, the rains had brought enough water to the city to meet drinking water needs. The main reservoirs in the city recorded a 0.3 TMC (5.5 percent) increase after just two days of rainfall.
Tamil Nadu weatherman Pradeep Mohan says it is a particularly positive sign after the devastating floods and scant rainfall in 2016. "I think this idea that there is a shortage of water is sometimes assumed from merely day-to-day weather conditions. It’s all in the mind," he says.
The government, he says, has also done much to bridge the divide.
In the eventuality of no rains in June, the government reinstated the Kudimarumathu scheme, an ancient system of conserving water resources for the effective harvesting of rainwater. Kudimaramathu is a practice where people contribute a percentage of capital or physical labour in managing water resources.
Further, the government had allotted funds for Chennai Metropolitan Water Supply and Sewerage Board’s project at Nolambur for an estimated cost of Rs 28.35 crore, a drinking water project for Karapakkam at an outlay of Rs 20.56 crore, and a drinking water project for Maduravoyal at a cost of Rs 60.96 crore.
Veeranam tank is another source that the government has actively pursued. After the South West monsoon, the dry water tank in Cuddalore received an inflow in about 10 days in November 2017. This was as a result of water released from Mettur for irrigation and would reach Veeranam through the Coleroon and Vadavar channel. This, in effect, has reduced the water shortage in South Chennai majorly. The department first supplied the water to the locality of KK Nagar in Chennai and diverted water from there to residences in other localities.
Desalination plants and mines
The government is heavily banking on desalination plants. "I think they are essential to solving the water crisis in Chennai, so I only see it positively," says Mohan. The Tamil Nadu government is investing heavily in these plants in order to meet 65 percent of Chennai’s water requirements. The state has two plants in Minjur and Nemmelli, having a capacity of 100 MLD each. This has sufficiently replaced the government’s dependence on groundwater. Chennai plans on setting up its first off-shore desalination plant off the Ennore coast. Sikkarayapuram and Neyveli quarries are seen as another source of water. The government has just recently tapped the possibilities of better water management which will come of need in the possibility that the city will dry up. The government is also treating the water to make sure that heavy metals don’t get in the way. This move could easily contribute to a minimum of 30MLD in the summers.
The grace of Krishna river
The water from Krishna river has proved essential to Tamil Nadu’s water shortage in the past.
As per the agreement between Tamil Nadu and Andhra Pradesh, a total of 12,000 mcft every year must be supplied to Chennai, of which 8,000mcft should be provided between July and October. But since the implementation of the project in 1996, Chennai has only received 77,000 mcft of water.
But that is slowly changing. Nearly 2,278 mcft reached Chennai through the city’s Poondi reservoir in 2016-17, courtesy the Krishna river.
Andhra Pradesh released 3.33 tmc ft of water from the Krishna river to Tamil Nadu to meet the drinking water requirement of Chennai city in January 2018. This came after the Tamil Nadu Water Resources Department wrote a letter to the Andhra Pradesh government stating the storage in the reservoirs in Chennai was only 46 percent.
Telangana has been fighting for lesser allocation for Andhra Pradesh, apart from their and Andhra Pradesh’s fight for Srisailam and Nagarjuna reservoirs in Krishna river. But after a good monsoon and desalination plants to the rescue, Chennai’s share of water is far from being touched.
"We need to stop thinking so negatively," says Nathan. "The city has so many sources and has ramped up drinking water supply through various measures. We must give them some credit," he says.
Pradeep John warns of rumours. "The Metro Water department has issued a press release not to worry and people still do," he says. Chennai is safe for now, experts say. But only the monsoon this year will tell.
Updated Date: Mar 21, 2018 16:39 PM