6. For the purposes of paragraphs 3 and 4:
(a)in the case of an accumulation, the remedy shall be its removal or such other protective works or measures as may be reasonably required by the Agency; and
(b)in the case of erosion or alteration of tidal flow or littoral drift, the remedy shall be the carrying out of such reconstruction works and other protective works or measures as may be reasonably required by the Agency;
provided always that the Agency will not require a remedy which results in betterment upon the average levels of accumulation, erosion, tidal flow or littoral drift for 2 years prior to the Agency’s requirement.