Minnegang Creek Flood Study Report - Wollongong City Council

Appendix BGLOSSARYAnnual Exceedence Probability (AEP)Australian Height Datum (AHD)Average Recurrence Interval (ARI)cadastral basecatchmentdischargefloodfloodplainthe chance of a flood of a given or larger sizeoccurring in any one year, usually expressed asa percentage.a common national surface level datumapproximately corresponding to mean sealevel.the long-term average number of years betweenthe occurrence of a flood as big as or largerthan the selected event, eg. floods with adischarge as great as or greater than the 20 yearARI flood event will occur on average onceevery 20 years. ARI is another way ofexpressing the likelihood of occurrence of aflood event.information in map and/or digital formshowing the extent and usage of land includingstreets, lot boundaries, water course.the land area draining through the main stream,as well as tributary streams, to a particular site.It always relates to a specific location.the rate of flow of water measured in terms ofvolume per unit time.relatively high stream flow which overtops thenatural or artificial banks in any part of astream, river, estuary, lake or dam and/oroverland runoff before entering a watercourseand/or coastal inundation resulting for superelevated sea levels and/or waves overtoppingcoastline defences.area of land which is subject to inundation byfloods up to the probable maximum flood eventie flood prone land.SV8507-DO-001 Rev 2 B-118/10/02