Where land is chargeable land during part only of the year for which a drainage charge is raised, a proportionate part only of the charge shall be payable in respect of that land; and any amount overpaid shall be repaid.

Where the area of chargeable land in respect of which, apart from this sub-paragraph, a sum is payable by any person by way of a drainage charge consists of or includes a fraction of a hectare, then for the purpose of calculating that sum the fraction shall be disregarded if it is less than one-half and treated as one hectare in any other case.