Section 8. Application of revenues of a public improvement or part thereof, or service

For the purpose of determining the amount of taxes which may  be raised on real estate pursuant to section ten of article eight of the
  constitution the revenues received in each fiscal year  by  any  county,
  city  or  village  from  that  portion  of  a public improvement or part
  thereof, or service, owned or rendered by such municipal corporation for
  which bonds or capital notes are issued after  January  first,  nineteen
  hundred  fifty,  shall  be  applied first to the payment of all costs of
  operation, maintenance and repairs thereof incurred during  such  fiscal
  year,  and  then  to  the payment of the amounts required in such fiscal
  year to pay the interest on and the amortization of, or payment of, such
  indebtedness contracted for such public improvement or part thereof,  or
  service,  or such revenues may be deposited in a special fund to be used
  solely for such payments. The  provisions  of  this  section  shall  not
  prohibit  the  use  of  excess  revenues  for any lawful county, city or
  village purpose.  The provisions of this section shall not  apply  to  a
  public improvement or part thereof constructed to provide for the supply
  of  water  or to a joint sewage or drainage project described in section
  15.00 of the local finance law.