1.  In Mumbai, BMC provisions for providing 90 liters of water per person, on the average presumption that there are minimum 4-5 persons residing in the unit.  That means about 400-450 liters of water per flat.  For which the BMC grants appropriate permission for the thickness of the water pipe-line (i.e. 1/2″ line or 1″ line or 1.5″ line and so on), based on the above calculation and at the supplied pressure controlled by the BMC hydraulic dept.

2.  Water is supplied to the groundwater tank, after which the management may load the water on the over-head tank, from where it is supplied to individual houses for restricted or unrestricted timings.

3.  Individual houses may further store the water at their convenience in buckets, drums or overhead loft tanks. If somebody has installed loft-water tanks without permission, then at the most BMC may service notice and levy penalty and/or remove the loft-water tank.

4.  However, to store water on “one” internal overhead loft tanks, a flat owner has to take separate permission from the BMC, which is easily available for a fee, subject to the stability of the building and that it does not overload the building structure AND subject to the water limitation as mentioned in point no. 1 above.  However, if the building is consuming more water than the permissible limit, (determined by the water bill) then such permission for such over-head loft tanks is refused.