Section 19(1)(a) in The Mumbai Municipal Corporation Act, 1888
(a)[ The [State Election Commissioner] [This portion was substituted for the portion beginning with the brackets, letters and words '(a) the area of Greater Bombay' and ending with the words 'by the State Government in the Official Gazette' by Maharashtra 15 of 1991, Section 3(a).] shall, from time to time, by notification in the Official Gazette, divide the area of [Brihan Mumbai] [These words were substituted for the words Greater Bombay by Maharashtra 25 of 1996 (w.e.f. 4.9.1996).] into wards and specify the boundaries thereof, so that, as far as practicable, all wards shall be compact areas and the number of persons in each ward according to the latest census figures shall approximately be the same. Each of the wards shall elect only one councillor:]