Payments by local authorities to water authorities4.
Subject to article 7 below, for each relevant year the Perth and Kinross Council shall pay–
(a)
to the North Authority a sum calculated in accordance with the formula in article 3(1) above, but for the purpose of that calculation the area of that Council shall be treated as if it did not include the first added area;
(b)
to the East Authority a sum calculated in accordance with the formula in article 3(1) above, but for the purposes of that calculation the area of that Council shall be treated as if it consisted only of the first added area.