Many buildings in peri-urban localities, including in areas that were merged with Chennai Corporation, have not implemented the rainwater harvesting system properly, according to Rain Centre.
The voluntary organisation based in Mandavelipakkam (Phone: 24918415) that promotes harnessing of rainwater proposes to conduct awareness programmes to sensitise the residents and builders in these areas. Rain Centre director Sekhar Raghavan said the dependence on groundwater is relatively high in the suburbs.
Not many people, however, are keen on implementing RWH system to recharge their main source of drinking water. During a recent inspection of houses and buildings in various suburbs, including Selaiyur, Pallavaram and Chromepet, the Centre's volunteers found that only a few had effective RWH structures.
Groundwater recharge is sustained in peri-urban areas owing to ponds and lakes. If RWH is done, there would be significant improvement in the water level and quality. Harnessing rainwater would also minimise the flooding on the roads, Mr.Raghavan said.
On residents' hesitation about harnessing rainwater in hard rock and clay areas, he said in localities such as Ambattur that have clay soil, a deeper recharge well can be constructed. Shallow wells could be made use for recharge in hard rock areas such as Pallavaram and Tirusulam.
Representatives of residents' welfare associations said that though people are aware of the system, many did not implement it owing to lack of monitoring by the local bodies. K.Ganapathy, a resident of Ambattur, said “We conducted campaigns. As the years passed by, people stopped maintaining their structures. Some of the big residential complexes have such systems.”
Owners of individual houses do not attach much significance to RWH systems unlike those of apartments where the cost and maintenance is shared among many households. Space is also a constraint in many individual houses. P.Karunakaran, a building contractor in Poonamallee: “Neither officials insist on RWH while sanctioning plans in suburbs nor owners show interest,” he said.
S.Ramaprabhu, licensed building surveyor in R.A.Puram, said the government must insist on RWH systems as done earlier. Unlike those in city, residents in suburbs do not show structures in their building plans.
L.Moorthi, former Chairman of Tamil Nadu unit of Builders Association of India said only 30-40 per cent of the residents maintain their structures properly. Many times, contractors are unable to accommodate such systems owing to lack of funds.
Sources in the local bodies in peri-urban areas admitted that harnessing of rainwater is not being done effectively. There was a provision to get a refund of deposit towards RWH, but there is little awareness about it among the residents.
Metrowater's RWH campaign
Meanwhile, Chennai Metrowater has started campaigning about the significance of RWH structures. A vehicle with working models of RWH has so far covered Ayanavaram, Perambur, Koyambedu, Purasawalkam and Royapuram.
Residents can harvest up to 40 per cent of rainwater falling in their premises during showers. The water agency's officials would inspect buildings and houses to assess the condition of the RWH structures.
A press release from Metrowater said that residents have to remove and clean the filter materials such as sand, pebbles and blue metal and refill them in chamber.