Bangalore Metro Rail Corporation Ltd. (BMRCL), which is constantly exploring different avenues to enhance its non-traffic revenue to cushion its operational expenditure, is now tapping rainwater collected on the rail viaduct.
To tap the rainwater collected on its vast elevated corridor network — 33.42 km long and 10 metres wide on Phase I — BMRCL has sought private sector participation and wants the project to be executed under a public-private partnership.
The viaduct, BMRCL said, is supported by concrete piers at an average distance of 28 metres.
These columns have pipes that will collect the rain Bangalore receives between July and November every year.
Clean water
BMRCL said the water thus collected will be clean as the viaduct itself is regularly cleaned. There is no oil pollution on the viaduct. Besides, the coaches are closed, so there's no chance littering on the tracks.
The selected private partner will have to harvest the rainwater in collection tanks of suitable size at convenient points, treat the water and supply the potable water on commercial terms to bulk consumers.
International firms too may express their interest as a joint venture with local firms having major share (more than 51 per cent).
Upon selection, the concessionaire will have to design and erect the rainwater harvest system, treat the rainwater and to sell it for a period of 15 years.
Bangalore Metro will give a month to shortlisted firms to conduct detailed technical and commercial studies. While the technical bid should detail the engineering system, the financial offer should specify the annual amount the bidder is ready to pay BMRCL. The concession amount will increase by 2.5 per cent at compounded rate every year.
R.R. Doddihal, BMRCL Chief Engineer (Reach 4), who is in charge of the project, told The Hindu the corporation has roughly estimated the quantum of rainwater available for harvesting.
