PUNE: The Groundwater Survey Development Agency (GSDA) has provided structural design of rainwater harvesting (RWH) to the Pune Metro, making it the first major infrastructure project in Maharashtra to incorporate the systems of collecting rainwater at its stations and along the route.
Rainwater harvesting will be implemented in two stretches first. This facility will help store up to 50 per cent of rainwater that metro venues recieve.
Milind Deshpande, Regional Deputy Director of GSDA, told Sakal Times that from the average rainfall per day, i.e, 20 mm, around 8.75 mm of rainwater per day per structure will be used to recharge groundwater level from the elevated metro track.
“There are two ways of RWH including recharge to subsurface and to store water for future. We have only given Pune Metro the technical design of rainwater recharge structure for which we have done hydro geological and geophysical study to determine whether the sub surface and aquifer recharge exist or not. GSDA will act as a project implementing agency to provide technical support to the Pune Metro.”
Deshpande said, “There are multiple layer aquifers existing below subsurface as derived on the basis of hydrogeological and geophysical survey and it has low and moderate resistivity zones which are feasible for recharge of groundwater.”
PROCESS OF RECHARGE
Deshpande explained the procedure of installing the RHW system on elevated track, saying on every alternate pillar, there will be a collection chamber with a recharge shaft located in the pillar between them. The rainwater falling on the track will flow through a passage of the pillar. It will get collected in the chamber. One pipe from each chamber will be connected to shaft, where water will be filtered and percolated into the aquifers, he said.
RAIN WATER HARVESTING ON PUNE METRO TRACK
- Rainwater harvesting to begin in first two stretches of Metro, i.e Vanaz-Civil Court and PCMC-Range Hills.
- Harvesting system expected to catch up to 50 per cent of rainfall received at the metro stations and routes.
- 278 recharge shaft system proposed.
- From these shafts the rainwater will be filtered and percolated into the aquifers.
- From the elevated track the rainwater will recharge the aquifers and from the metro station, some rainwater will be stored, and rest used for recharge.
- Annually, about 82,466.80 metre cube (from tracks) and about 18964.04 metre cube (on station) rainfall will be available on Range Hill and Vanaz metro depot.