16. The total of the expenditure properly incurred by the shadow authority before 1st April 2019 is to be divided among, and paid by, the District Councils in such proportion as may be agreed between those councils; but, where the shadow authority notifies the Secretary of State that there is no such agreement, the Secretary of State may—
(a)determine the proportion in which that expenditure is to be divided and paid; or
(b)appoint an arbitrator for that purpose.