It is never too late when it comes to harnessing rainwater, be it summer or winter. The northeast monsoon has already set in, but several people are pondering over desilting their rainwater harvesting structures or constructing more.
Rainwater harvesting (RWH) experts in the city note that many people realise the significance of saving rainwater only after a bout of rainfall.
Though months of April and May are ideal to construct RWH structures, residents must be prepared throughout the year as the rainfall pattern has become unpredictable.
Sekhar Raghavan of the Rain Centre said that nearly 90 per cent of the residents carry out maintenance work of the RWH structures only during the monsoon. But, as it takes only a few hours to clean the structures, it can be done during dry spells in monsoon.
“A recharge well must be 10-15 ft deep and 3-4 ft wide to reap the benefits of the showers. Residents of apartment complexes must construct three wells. Those who don't have space may go for recharge pits. However, its use is short-lived,” he said. Residents may have problems while cleaning or constructing recharge wells during rainy season as the water table would be on higher level. The Rain Centre also provides assistance for construction and cleaning of such structures.
Chennai Metrowater officials conducted a random survey on RWH structures in buildings across the city and provided tips for maintenance. The 759 observatory wells are being monitored for water level and quality.
Officials said residents must choose the design of the structures according to soil condition in their locality. If the water overflows from the RWH structures, it needs cleaning. Besides rooftop water, the surface runoff could be diverted to wells using gutters.