24x7 water supply city’s pipe dream?
The construction of four dams has been in the planning stage for eight years and is expected to add 2,891 MLD to the existing supply of 3,750 MLD sourced from seven damsmumbai Updated: Aug 29, 2016 01:09 IST
While a good rain has solved your immediate water woes, the city still faces a shortfall of 500 million litres daily (MLD) to meet its current demand of 4,200 MLD. The civic body has an ambitious plan of four dams — Gargai, Pinjal, Khargihill and Bhugad — to supply 6,943 MLD by 2041 to suffice a population of 21 million (projected as per the water department), but, for now, the plan is largely on the drawing board.
The construction of four dams has been in the planning stage for eight years and is expected to add 2,891 MLD to the existing supply of 3,750 MLD sourced from seven dams. But, going by the figures, there is likely to be a shortfall of 302 MLD water even after 25 years.
The Brihanmumbai Municipal Corporation (BMC) took its first step towards getting the water supply plan on track by floating tenders to appoint consultants for preparing a design project report (DPR) for Gargai.
The construction of the other three dams will be under the Damanganga-Pinjal river link, a joint national project between Maharashtra and Gujarat. Bhugad, Khargihill and Pinjal dams are jointly expected to supply 2,451 MLD to the city. The water from these dams will be brought till Gundavali, using a 64-km-long tunnel, from where it will be brought to the Bhandup reservoir.
While the civic body received the design project report of the Damanganga-Pinjal link project (cost: Rs15,000 crore) two years ago, there is no clarity yet on its implementing agency.
While the National Water Development Agency (NWDA) will oversee it, it is not yet clear whether the civic body or the state will construct Bhugad and Khargihill dams.
In case of Pinjal dam, the inclusion of an irrigation component has forced the civic body to give up 10% of Pinjal’s total water stock of 410 million cubic meters to the state, but again there is no clarity on which authority -- civic body or state -- will construct the dam.
A civic official said, “While the BMC bore 70% of the construction cost of Bhatsa, it was not constructed by us. This can also happen for Pinjal, if the government chooses to take over, as it will also have an irrigation component involved in it. So far, there has been no such demand.”
The overall time overruns for these projects could hike the cost of these dams considerably (minimal 10%), especially given the civic body seemed to be working without any fixed timeframes.
The bigger question that could challenge the premise of these projects is the population estimates given by the civic body. The population estimate of the city (21 million) given by the water supply and projects department is contrary to the estimates in the revised draft development plan-2034 (14 million). The 2011 census had also shown the city’s population growth chart is on a decline.
A civic official said, “We have considered the population to be on the higher side going by various development policies drafted by the government and civic body. This projection was however done by the water department about four years ago. So far, we have not noticed any dip in the population trend.”
Sanjay Mukherjee, additional municipal commissioner, said, “We have floated tenders for appointing consultants for preparing the DPR for Gargai dam. The biodiversity study report for both Gargai and Pinjal is expected by September.”