In 2003, Tamil Nadu broke new ground, when it made rainwater harvesting mandatory. Santha Sheela Nair, who was then the Municipal Administration and Water Supply (MAWS) secretary, was the brain behind the move. The objective was achieved with incredible swiftness.
On 19 July 2003, the ordinance that all buildings should have a rainwater harvesting system was issued; and, it was reported that by August 2003, 90%compliance was achieved.
A mass movement
At that time, Chennai was on the cusp of a quasi-drought situation, and the idea of rainwater harvesting (RWH) resonated with residents. “In the early 2000s, the water crisis was worse than it is today. Water was being transported from Erode and Nallur by tankers and trains. We were dependent largely on water from Red Hills lake and Krishna water,” recalls the 1973-batch IAS official.
Through rain centres, seminars, workshops, rallies, door-to-door campaigns, celebrity endorsements, self-help groups and non-governmental organisations, the common people and even Ministers were sensitised on the necessity of RWH.
“It became a mass movement,” she says, adding, “Yes, some termed the ordinance draconian, especially when a penalty for non-compliance was announced. The sensitisation, however, was so strong and genuinely convincing that it received support from all quarters, including the judiciary.”
Santha, who has retired from service but still remembered as the ‘water woman’, observes that rainwater harvesting continues at the individual level, but enthusiasm over it, witnessed a decade ago, is missing.
“Instead, we are witnessing over-exploitation of groundwater. People believe that desalination is the solution to the looming water crisis,” she notes, adding that desalination, however, comes with a huge, and at times, irreversible cost.
“The cost of desalinating is ₹45 to ₹50 per kilo litre of water. This is expensive and energy-intensive. While countries across the globe are relying on available water resources and recycling waste water, we are producing brine as effluent in the process of desalination. This brine, in turn, goes back to the shore and its high concentration causes ecological concerns. An RO plant is no different; it produces high amounts of reject, which eventually goes back to the water system. So, we are caught in a vicious circle,” she says.
The way forward
“We have to revisit rainwater harvesting,” says Santha. “We have to revive several RWH structures that have gone to seed. Build sumps below buildings to collect rainwater and store it. This will provide the water requirements of the entire building. The amount of rainwater we receive is sufficient to collect 20 to 30 litres per household, for drinking and cooking.”
Until a few years ago, rainwater harvesting recharged aquifers. “It is time to replenish surface water resources through RWH. This way, we can revive the old open wells as well.”
Santha suggests recycling waste water as an alternative. Waste water can be used for non-potable requirements like toilet flushing and washing. “Use grey water from washing machines and bathroom showers to water your backyard garden; or, after passing through a filter bed, it can be reused for flushing and washing,” she suggests.
She believes builders also should play a vital role in promoting rainwater harvesting by spreading awareness about it among their customers. “Several residents opt for Metrowater as they don’t want to bear the additional cost of having a rainwater harvest structure. So, builders have to create awareness that an assured source of supply is better than drilling deep and desalination,” she says.
