Commonwealth Consolidated Acts Commonwealth Consolidated Acts(1) The Basin Plan must also:
(a) specify the conditions under which, due to one or more of the circumstances referred to in subsection (2):
(i) Tier 2 water sharing arrangements cease to apply; and
(ii) other arrangements ( Tier 3 water sharing arrangements ), provided for in the Agreement, commence; and
(b) specify the conditions under which Tier 3 water sharing arrangements cease to apply and Tier 2 water sharing arrangements recommence.
(2) For the purposes of paragraph (1)(a), the circumstances are:
(a) there are extreme and unprecedented low levels of water availability in the River Murray System; or
(b) there is extreme and unprecedented poor water quality in the water available in the River Murray System to meet critical human water needs; or
(c) there is an extremely high risk that water will not be available in the River Murray System to meet critical human water needs during the next 12 months.