Dams3.

Every—

(a)

dam the construction of which commenced on or after 1st January 1995,

(b)

mill dam constructed after 28th July 1865, and

(c)

portion, of any other mill dam, renewed or repaired at any time after 28th July 1865,

shall be made and maintained watertight by the operator so that no water, which can reasonably be prevented, shall run through it except when necessary to maintain the stability of the dam.