One of the Hawaiian Island’s unique beaches is at Anaehoomalu Bay on the island ofrnHawaii. In addition to the protected beach and swimming area, the Anaehoomalu site containsrnhistoric fishponds and other areas of archeological significance immediately landward of thernbeach and adjacent to a major visitor hotel. The beach protects the fishponds as well asrnproviding for beach recreational uses. High waves, tides and storm surges, however, can damagernrecreation facilities, washing the beach sand into the ancient fishponds and deplete the beachrnarea. For over 20 years, this area has been protected through a flexible berm managementrnprogram, developed with a combination of wave forecast data and empirical evidence. Stormrnmonitoring and wave forecasts were performed, in order to investigate storm induced over-washrnand to prevent sand from infilling the fishponds, Beach overwash have been observed over thernpast twenty years. Overwash occurs especially when high tides are .75m above MLLW andrncauses beach loss and damage to the historic Hawaiian fishponds if preventative measures arernnot taken. The DeWitt beach berm, however, with the crest elevation of approximately 2m abovernthe natural backshore beach level, has prevented or greatly reduced the majority of fish pond andrnadjacent recreation infrastructure damage. Using data on the direction of incoming high waves,rnbeach maintenance personnel predict which sections of the berm/beach will likely receive thernmost severe damage, and actively rebuild damaged sections of berm until the high wavesrnsubside. After a storm front has passed, the height of berm has been lowered for convenience ofrnbeach users. However, beach personnel observations indicate that the majority of the bermrnshould remain in place to better withstand future wave action. Anaehoomalu Bay beachrnmanagement records maintained by Mr. Charles DeWitt for 20 years, has led to a successfulrn“soft” management scenario for this carbonate beach. These data and experiences may be usedrnin other recreationally important areas where cost benefit considerations warrant thernexpenditures.
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