Amidst complaints of ineffective rainwater collection in public spaces, the Water Resources Department is adopting a Japanese pilot model to save rainwater that otherwise gets wasted.
Besides, to find a solution to urban flooding and water shortage, a massive underground tank with a capacity of 6 lakh litres is being planned at the State Ground and Surface Water Resources Data Centre, Taramani. The pilot project initiated to study the economic viability of such structures has also envisaged emulating the concept to store rainwater in public spaces and on large campuses.
Inspired by the popular Japanese concept, the pilot project aims at constructing a massive structure spread over nearly 4,000 sq.ft. and at a depth of 3.5 metres to divert rainwater. Unlike the conventional concrete tank, this would be more of a composite structure with inner walls built using imported PVC plates and pipes and covered in concrete.
The use of Japanese technology is expected to be economically viable.
Officials of the Department said gigantic underground tanks had been built in Japan to divert floodwaters from waterways and it was later supplied throughout the year.
“We plan to compare the cost of the conventional concrete structure with this new technology through the pilot project to prove its cost-effectiveness ,” an official said.
Saving for rainy day
The project, taken up with the assistance of Japan International Cooperation Agency, would harness rainwater from rooftop measuring nearly 37,000 sq.ft. on the campus.
“We already have two storage tanks with one lakh litre capacity each and use the water between October and January. Water consumption on the campus works out to 22 lakh litres per year. About 250 employees have to depend on tanker supply for nine months,” the official added.
It will take two months to to build the underground storage tank.
The campus would have the potential to harness nearly 23 lakh litres of water despite deficit rainfall. If found economical, such structures could be constructed within a short period beneath parks, playgrounds and adopted in large government and apartment complexes.
Purifying water
“We could divert floodwater into these tanks and use it during summer. In Taramani, we hope the pilot model would help us achieve self-sufficiency in water needs,” the official added. There were also plans to purify the water and provide it to residents of neighbouring colonies through a water ATM.
