Central Coast Council has reliable flood records for Tuggerah Lakes that go back over 90 years. Since the documentation started, we have experienced 12 floods reaching a height of 1.5m above the Australian Height Datum (AHD or mAHD for metres above the Australian Height Datum) or more. The highest flood recorded for the lakes was 2.1 mAHD in June 1949. The most recent flooding event happened in February 2020 and reached 1.67 mAHD, becoming the 6th highest on record. It is followed closely by the ‘Pasha Bulker’ flood from June 2007 at 1.65 mAHD. The February 1990 and March 1977 floods also reached 1.6 mAHD.
|Date||Approximate Peak Lake Level (mAHD)|
A 100-year flood (also called a '1-in-100-year flood') is a flood height that has a 1 in 100 chance of being equalled or exceeded in any given year.
For Tuggerah Lakes, this '1-in-100-year flood' is estimated at 2.2m, which is just a bit higher than the level reached in 1949. Another estimate, the Probable Maximum Flood (PMF) refers to the largest flood that could conceivably occur in present climatic conditions. For our region, this is estimated at 2.7m.
The February 2020 and June 2007 floods were both 1-in-10-year Average Recurrence Interval floods. The Bureau of Meteorology classifies them as minor events. Typically, each year, there is a 10 per cent chance of a flood this size. Moderate floods are higher than 1.8m, and there have only been five of these in the past 90 years. The most recent one occurred in May 1964 and reached 1.9m. Luckily, since the 1930s, we have not experienced a major flood event that would reach 2.2m (or higher).