Friday, 18 December 2020

According to the Australian Bureau of Meteorology the risk of the Clarence River flooding this week has passed


Now that is looking more likely that rivers within the Clarence River catchment will be back to normal for the Yuletide season, here is a little local history......


Clarence Valley Council, retrieved 17 December 2020:


From the first cedar-getters and European settlers in 1830 to the commencement of sugar farming in 1868, only relatively small floods topped the natural river banks near the early settlements.


Over the following few decades, however, the security of the floodplain was seriously questioned. Floods overtopping the banks in that period included the great flood of 1890, with a height of 24 feet. This would be equivalent to 7.834 metres AHD (Australian Height Datum).


One of the floods in 1950 killed two people, over 1000 head of cattle and damaged several thousand homes.

The most recent floods have occurred in 2001, 2009, 2011 and 2013 and have reached levels of - 7.70 m AHD, 7.37m AHD, 7.64m AHD and 8.08m AHD respectively.


Since flood records commenced in 1839, Grafton has been subject to over 120 floods - the highest being in January 2013 at 8.08m…...floods occur more often from January – Apri…...[but also have been recorded in every month including on 19 December 1966 when flood waters passed through at below minor level at 1.2m and 16 December 2020 when flood waters reached minor level at 2.29m].


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