A person who--
(a) intentionally or recklessly destroys, damages, removes or interferes with piles or other materials that form part of, or have been fixed or placed in position in order to secure--(i) a sea wall or other structure designed to prevent erosion by the sea,(ii) the bank or bed of, or a dam, weir or lock located on, a river or canal,(iii) a drain, aqueduct, marsh or reservoir, or(iv) a dock, quay, wharf, jetty or other harbour installation,
(b) intentionally or recklessly opens a floodgate or sluice that is located at or on a dam, weir, reservoir or watercourse, or
(c) with the intention of obstructing or hindering the navigation of vessels or boats on a navigable river or canal--(i) interferes with or obstructs the flow of the river or canal,(ii) damages or interferes with the bank or bed of the river or canal, or
(d) destroys, damages or interferes with any structure or equipment constructed or installed in connection with the use of the river or canal for the purposes of navigation,is liable to imprisonment for 7 years.