Rainwater harvesting to be must in new buildings

                    Shailesh Gaikwad
                    Mumbai, May 16: Ever wonder how cities can evolve a sustainable way to meet growing
                    demand for water? Maharashtra has found the answer in an innovative development plan that
                    would make it mandatory for all new constructions in Mumbai and other cities in the state to
                    harvest rainwater.
 
 

                    Soon, anyone planning to construct a new high-rise in the ever-growing city will not get requisite
                    approvals from the municipal corporation unless the proposal is attached with a plan to store
                    rainwater.

                    ‘‘The cabinet has decided to implement the rainwater harvesting policy in urban areas. Now the
                    department is working out the details for amending the development control rules for the
                    purpose,’’said principal secretary (urban development) Ramanand Tiwari.

                    As per the plan which is inspired by the Chennai model, new buildings would need to have a
                    facility for collecting rainwater from rooftops and storing it in underground tanks for use during
                    the water scarcity days.

                    ‘‘Such a step is needed since the groundwater table is going down drastically. In the last two
                    months, it has gone down by 2 meters. If no steps are taken in the near future, we may have to
                    face water scarcity of an unprecedented nature,’’said water supply minister R R Patil.

                    Mumbai consumes about 3,000 million cubic litres of water every day. Rainwater harvesting is
                    seen as the best option to meet the burgeoning demand because on a 20 square-metre roof of
                    asbestos sheets, tiles or cement concrete, a minimum 3,000 litres of water can be harvested for
                    use for about four months by a family of five.

                    ‘‘Every year, about 20,000 localities in the state face acute water shortage during the six months
                    between December to May. The government has to provide tanker water for them. Through the
                    scheme, they will have at least drinking water for this period,’’ Patil pointed out.

                    However, builders had mixed opinions about the proposal. ‘‘Although it can be viable, I am
                    doubtful how the UDD will implement it,’’ said Hiren Patel of Atithi Builders. Buildings will
                    face problems of cleaning storage tanks, he said and wondered if the stored water would be
                    hygienic for use.

                    Jayant Mehta of Unique Constructions said the underground water tanks may create problems
                    for the pillars of the structure. Also, water reserve close to the building may pose a threat to the
                    construction, he apprehended adding that the UDD should work out the details so that the rule
                    should not become a problem in a city like Mumbai where it is difficult to have a parking lot in
                    the building premises.

                    A report has been sought from the Chennai municipal corporation so that the government can
                    study the obstacles faced in implementing the plans. For existing constructions, the government
                    is planning to offer incentives such as a concession in water charges for installing the rainwater
                    storage facility.

                    Since the water supply departments of the municipal bodies may not have the expertise needed,
                    the government will appoint a panel of NGOs to offer technical know-how to the new
                    constructions.

                    The development plan is likely to specify the constructions brought under the rules, guidelines
                    for implementation and legal norms to make rainwater storage compulsory, Tiwari said. Extent of
                    area under construction to be brought under the new rule will also be mentioned.

                    The rainwater harvesting scheme is already being implemented in rural areas and has evoked a
                    good response. ‘‘We need not make it compulsory in rural areas but there is no option for urban
                    areas,’’ said S D Thakre, joint secretary in water supply and sanitation department.