Section 94. Water works

In  case  the  city owns and operates a system of
  municipal water works, the commissioner of public works  shall  appoint,
  to hold office during his pleasure, a superintendent of water works, who
  shall  have,  under  the direction of the commissioner, the supervision,
  care, management and control of the  water  department  and  water-works
  system  of the city.  It shall be the duty of the commissioner of public
  works to see that the city has an abundant supply of pure and  wholesome
  water  for  public and private use; to devise plans and sources of water
  supply;  to  plan  and  supervise  the  construction,  maintenance   and
  extension  of  the water system and the distribution of water throughout
  the city; to protect it  from  contamination;  to  prescribe  rules  and
  regulations for its use, which, when ratified and approved by the common
  council,  shall  have  the  same force and effect as city ordinances. He
  shall have  power,  with  the  assent  of  the  board  of  estimate  and
  apportionment,  to  establish  rates  of  rents  to  be charged and paid
  annually  for  the  supply  of  water  or  for  the  benefits  resulting
  therefrom,  to  be called water rents, which shall be apportioned to the
  different classes of  buildings  in  the  city  in  reference  to  their
  dimensions and the ordinary uses of water for the same, and to different
  lots,  as may be practicable, and from time to time to modify and amend,
  increase or diminish such rates and to extend them to other descriptions
  of buildings, lots, establishments and uses. He shall also  have  power,
  with  like assent, to establish rates for the use of water in buildings,
  establishments, trades and other purposes  in  or  for  which  water  is
  consumed  beyond  the  quantity  required for ordinary purposes, and may
  require the same paid to him in advance, at the rates thus  established,
  before permission to use such extra quantity of water shall be given.