The objective of the study is to quantify the likelihood of coastal and associated waterway areas within major remote towns and indigenous communities on the West Coast, Arnhem Land and Tiwi Islands areas being inundated by storm tide caused either by severe tropical cyclones or broad scale atmospheric influences. The study outcomes provided inundation data showing storm tide elevation depth that corresponds to a specific return period risk or ARI (Average Recurrence Interval). The provided storm tide probability levels are 100, 1,000, 2,000 and 10,000 year ARI. The inundation extent shows the total storm surge (technical terminology is storm tide) hazard risk due to tropical cyclones in terms of the ocean water level comprising the combined effects of astronomical tide plus storm surge plus wave setup for three statistical Average Recurrence Intervals (ARI) at a nearby open coast location. The Primary Storm Surge (PSS) Zone refers to the extent of inundation for a storm tide event of 100 year ARI. The Secondary Storm Surge (SSS) Zone refers to the further extent of inundation for a storm tide event of 1,000 year ARI. The Extreme Storm Surge Zone refers to the further extent of inundation for a storm tide event of 10,000 year ARI. The extent of PSS is used for land use planning. The extent of SSS is additional information for risk analysis. The extent does not include the possible effects of much localised wave run up..
