Fearing that the city could face water shortage in the future too if rains fail, the Brihanmumbai Municipal Corporation (BMC) is looking for new sources of water.
In the absence of water reserves near the city, the BMC is looking at drawing water from Konkan.
The two proposals under consideration are diverting water from the Koyna hydropower project in Satara and from Patalganga river in Khopoli.
Water released from the Koyna hydro project goes into the sea. The BMC is considering diverting this water to Mumbai through pipelines.
Another option is water released from a power station at Khopoli in Raigad into Patalganga river. This can be diverted to Bhatsa dam, which supplies water to Mumbai.
Experts have questioned the viability of these projects. “To divert water from long distances one needs huge funds and even environmental clearance if there are forests on the way,” said S S Tinaikar, former municipal commissioner. “These projects have limitations.”
The demand for water in Mumbai is 4,200 MLD (million litres daily). The city gets 3,450 MLD from six lakes. The BMC estimates a rise of 100 MLD in the annual demand.
The water stocks in Modak Sagar and Upper Vaitarna the two biggest lakes that supply water to the city and western suburbs is dipping drastically leading to a dip in the water levels in the Bhandup Master Balance Reservoir (MBR).
The BMC has imposed a 15 per cent water cut to meet the shortfall. The civic body expects the Middle Vaitarna dam, which will provide 455 MLD, to be completed by 2012. The Gargai and Pinjal dams will be completed by 2021 and provide 1,300 MLD of water.
Additional Municipal Commissioner Anil Diggikar feels demand may stabilise in future.
“We work according to the Chitale Committee report which had said that population may stagnate after 2021 as there won’t be any place to accommodate people,” said Diggikar. “We are considering that there won’t be a rise in demand after that.” Tinaikar, however, argued that population is never constant.
The Chitale Committee, headed by former irrigation secretary Madhav Chitale was appointed in 1993 for advice on long term planning for augmenting water supply to the city. The committee had recommended that the Middle Vaitarna and Gargai, Pinjal projects be given priority.