(1)Where—
(a)by reason of the construction of works on or over land in any part of a police area the number of people resident in that part of the area is temporarily increased to an abnormal extent, and
(b)the police authority for the area consider it expedient because of the circumstances aforesaid that the number of constables available for duty in that part of the area should be increased during the continuance of the said circumstances,
the police authority may direct the chief constable of the police force maintained for the area to make such arrangements as he considers necessary (whether by the appointment of temporary constables or otherwise) for increasing the number of constables so available accordingly.
(2)Where such arrangements as are mentioned in subsection (1) of this section have been made, the police authority may recover from the occupier of the land (or, if the occupier proves that some other person is responsible for the construction of the works, from that other person) such sums representing the cost necessarily incurred in each year in pursuance of the arrangements as may be agreed, or as may be fixed by a single arbiter appointed (in default of agreement as to the appointment) by the sheriff.
(3)The provisions of this section shall be without prejudice; to the provisions of section 17(3) of this Act.
(4)In this section " sheriff" does not include a sheriff-substitute.