He teaches economics in a college and he can also teach you a thing or two on how to economise on water. The family of associate professor Joseph N.M. at Madanthyar in Belthangady taluk of Dakshina Kannada consumes rainwater conserved for eight months in a year.
The rainwater harvesting method adopted by Mr. Joseph — who teaches economics in Sacred Heart College, Belthangady taluk — is quite unique. He collects filtered rainwater from the roof above the terrace and stores it in 12 interconnected plastic tanks on the terrace. Excess water flows from one tank to another and finally flows down to a sump. When the sump is full, the excess water flows to an open well and a borewell for recharging. As the four-member family uses water stored in the terrace tanks, the tanks get filled up continuously for six rainy months from June. The family manages with the stored rainwater for two more months — one month before and after the rainy season. As Madanthyar is located not far from the foothills of the Western Ghats, it receives some good summer rains in April and May.
The family has been using rainwater for drinking, cooking and washing from the last four years. “None of us has suffered from any water-borne disease in the four years. Water analysis reports have termed the harvested rainwater fit for drinking,” Mr. Joseph said.
The 12 tanks store 22,500 litres of water at a time and the sump 69,500 litres. The terrace has a 2,700 sq. ft roof. Mr. Joseph said one litre of water could be collected if there is 1 mm rainfall on a one sq. m area.
He said he harvests 10.7 lakh litres of water in a rainy season. The family uses about half of it directly and the remaining flows to the wells for recharging. He said the tanks on the terrace should be placed only on top of beams or pillars to withstand their weight.
Mr. Joseph said storing water on the terrace helps in effective water management even if there was no continuity in rainfall. With this, there is no need to depend much on other water sources.
