And watching the media coverage, Mr Halliday realised he had no knowledge of what the various flood gauge heights actually meant.

“I monitored the flood watching the Bureau of Meteorology website but I didn’t really know what the various river heights meant for my house,” he said.

“At what point does water cross the road? When does it endanger the house? At what height do I have to clear machinery and things from the sheds?”

Using historical flood data, photographs and contemporary newspaper reports, Mr Halliday produced a graph that shows the heights and frequency of floods in the Macleay Valley greater than 5.5m from 1838 until the present day.

“Interestingly enough there has never been a flood of greater than that height during September, October or December so that’s when you want to go on holidays,” he said.

Extensive flood mitigation work by the council beginning in the 1950s has lessened the chances of a catastrophic flood.

“It has made it a bit harder to compare between different floods because of all the work that has been done so flood gauge heights don’t mean the same thing in different years,” he said.

“With the flood gates at Belmore and Kinchela and the ocean outlets at Ryans Cut near Crescent Head and Big Hill gates, it may not even be possible to reach the same heights.

“I have a photo of the house across the street that had 35cm of water over the floor in the 1950 flood which was the top end of a 1 in 100 year flood event.”

Mr Halliday says the current and former councils do not receive enough credit for the work they have done.

“When you start researching it, you realise that flood mitigation works have been one of the most important tasks the council has undertaken,” he said.

“I think the council needs to be congratulated on what they have done and are doing.

“Things like the flood SMS service are fantastic and the council should get credit for having an effective service that also saves the ratepayers money.

“Ultimately though I think people really need to educate themselves about flood heights and what they mean for them.”

The Bureau of Meteorology website address is www.bom. gov.au