CLARENCE Valley businesses and residents will have flood modelling that shows the depth of flood water that would inundate their homes if the region's levees are overtopped.
At the Grafton Chamber of Commerce breakfast meeting at the Crown Hotel on Wednesday, the Clarence Valley Council's local emergency management officer, Keiran McAndrew, revealed the council was working on creating the models.
"The modelling will show exactly how much water will come into each building," Mr McAndrew said.
"It should be available in the next few years."
At the meeting Mr McAndrew showed the effect of a one-in-50-year flood and the depth of water at a number of landmarks in Grafton and South Grafton.
"For example it shows that at the fig tree on the corner of Prince and Victoria streets the water will be 15cm deep, but further down Prince St, around Pound St, it would be over my head," Mr McAndrew said.
He said he had produced the flood depths for each of the region's aged care centres as this information would be critical for them in planning their response to a flood threat.
Mr McAndrew said the improved data on flooding in the Valley had led to a change in the risk categorisation of floods.
He said the 2013 flood, which has been bracketed with the 1890 flood as the benchmark of floods in the recorded history of the Clarence Valley, is now regarded as a one-in-30-year flood.
Mr McAndrew said the biggest development to aid the creation of digital flood modelling was a technique called LIDAR, which he described as an aerial equivalent to sonar in ships.
"It's basically a plane flying over an area and using a light beam to map the area," he said.
"It's able to get rid of things like houses and trees and reveal highly accurate topographical information."
The flood models also survey the river beds and rainfall data used to calculate the input from the river and its tributaries.
The presentation also included animations which showed how much of Grafton would be inundated when a one-in-100-year flood strikes.
All the information is on the council's website at http://www.clarence.nsw.gov.au/ under the tab, online mapping.