Lake Macquarie - Floodplain Management Plan August 2001

Floodplain Management Plan Report and figures.

This Plan provides the basis for the future management of flood liable lands adjacent to the lake in the Lake Macquarie City Council area. The Plan was developed from the Lake Macquarie Flood Study (Part 1 - January 1998 and Part 2 - April 1998) and the Lake Macquarie Floodplain Management Study (August 2000).

The Lake Macquarie Flood Study determined design flood levels for the 1%, 2% and 5% AEP floods and an Extreme flood event. It examined the still water level and also the effect of wave runup along the foreshore. The design events represent floods which have a certain probability of occurrence. The “1% AEP” or “1 in 100" flood has a 1 in 100 chance of being equalled or exceeded in any year. On a LONG TERM average it will happen once in every 100 years, but it is wrong to think it can only happen once in a century. Because floods are random events there is still a 1 in 100 chance of such a flood occurring next year no matter what happens this year.