PRESAGING BEACH RENOURISHMENT FROM A NEARSHORE DREDGE DUMP MOUND, MT-MAUNGANUI-BEACH, NEW-ZEALAND

A study was undertaken to ascertain whether material to be dredged fro m the shipping channel through a large ebb tidal delta at the entrance to Tauranga Harbor, New ZeaLand, could be dumped in shallow water (5- 8 m below Mean Sea Level) off the downdrift Mt. Maunganui Beach and in duce beach nourishment. Investigations included comparison of sediment ological texture of the material to be dredged, the dump site on the b each; a fluorescent sediment tracing experiment; application of standa rd Shore Protection Manual ''fill'' and ''renourishment'' factors; and application of the new techniques of KRAUS et al. (1991), and HANDS a nd ALLISON (1991). Results illustrated textural similarity between the sediments to be dredged and the natural beach and dump zone, while th e sediment tracing experiment indicated predominantly onshore movement . Application of the S.P.M. techniques along with the new techniques o f KRAUS et al. (1991) and HANDS and ALLISON (1991) gave consistent, pl ausible indications that beach nourishment would succeed from the near shore dumping. This was confirmed by sequential beach and bathymetric surveys subsequent to dumping.