4(1)An appropriate department may cause a survey and examination to be made—N.I.
(a)of any tidal work; and
(b)of the land upon which it is proposed to construct any such work.
(2)Where an appropriate department incurs any expenditure in pursuance of sub-paragraph (1), it may recover the amount of that expenditure from the local harbour authority which proposes to construct, alter or extend the work in question as if it were a debt due under a contract.