This Part does not apply to dam works that –

(a) are undertaken for the primary purpose of storing waste; or

(b) consist of the construction, erection, enlargement or modification of a levee or bank, in preparation for or during a flood, that is a levee or bank that is entirely removed within 4 weeks after the day on which the levee or bank was constructed or the flood ceases; or

(c) are exempted from the operation of this Part under section 140 .