BEACH NOURISHMENT AS A MANAGEMENT TECHNIQUE

Abstract

Beach nourishment is considered an environmentally safe management technique, since an unsuccessful nourishment project would simply result in the redistribution of borrow material by wave action into environments more in keeping with a state of equilibrium. No permanent modifications of the beach and nearshore environment need result, and since no permanent structures are required for beach nourishment, the management commitment allows rapid project abortion if necessary. Beach nourishment monitoring has usually been concerned with evaluating changes in the extent of subaerial beach and/or retention of fill volume. These parameters are important, but it is also necessary to consider the way in which nourishment sand is taken up by the beach system since relationships between volume change, change in extent of subaerial beach, and changes in beach morphology are complex. This paper is concerned with evaluating beach nourishment on the Gold Coast (Figure 1), Australia's major resort, where 2.A million cubic metres of fill were applied in the largest beach nourishment project attempted in this country at the time of writing. Methodology, reported in Chapman & Smith (1977) and Chapman (1978a) included repetitive profile survey from backshore to point of zero change in inshore zone (over 4.00 profiles) using highly accurate techniques, and use of 38 tonnes of tracer, which was injected into the dredge line at a controlled rate.