a sufficient water supply and sewer "a sufficient water supply and sewer" means a water supply and sewer which are sufficient and reasonably available for use in or in connection with the efficient flushing and cleansing of and the efficient removal of excreta and urine from such number of proper and sufficient water-closets and urinals as in pursuance of this section may be required to be provided in any particular case or in connection with a sink or bathroom, and a sewer shall be deemed reasonably available for use which is within one hundred feet of the boundary of the premises in which is situated the house in respect of which closet, sink, urinal, or bathroom accommodation is to be provided. ACT 133 - STREET, DRAINAGE AND BUILDING ACT 1974 58. Interpretation.