If a local authority who supply water under this Act so resolve, the water rates shall, notwithstanding anything in the Waterworks Clauses Act, 1847, be payable in advance by half-yearly instalments in respect of the half-years commencing on the first day of April and the first day of October, but no proceedings shall be commenced for the recovery of any such instalment until the expiration of two months from the first day of the half-year in respect of which it has been demanded.
While such a resolution is in operation, if the person who is, or who but for the provisions of the last preceding section would be, liable to pay the water rate payable in respect of any premises is in occupation of those premises during a portion only of a half-year, he, or, as the case may be, the owner of the premises, shall be liable to pay so much only of the half-yearly instalment as bears to the whole instalment the same proportion as the number of days within the half-year during which the first-mentioned person is in occupation bears to the number of days in the half-year, and, if either of them has paid any greater proportion of the instalment, he shall be entitled to recover the excess from the local authority, except in so far as he has previously recovered it from an incoming occupier.