(1)  Where the taking, or the taking and use, of water from a water resource has, or is likely to have, a detrimental effect on the quantity or quality of water that is available from another water resource, the water management plan for the first-mentioned resource –

(a) must take into account the needs of persons and ecosystems using water from the other resource as well as the needs of persons and ecosystems using water from its own resource; and

(b) may, to achieve an equitable balance between competing interests, include provisions designed to prevent or reduce any such detrimental effect.

(2)  Where the taking or use of water from a water resource affects, or is likely to affect, the management of water in another water resource, the water management plan for the second-mentioned water resource may include provisions relating to the taking or use of water from the first-mentioned water resource.