Flood 'hot spots' identified
FLOOD ‘hot spots’ across the entire Richmond River catchment area have been identified in a new report which has taken almost five years to complete.
The Richmond River Flood Model 2010 is now the most comprehensive flood model on the NSW east coast.
Richmond River County Council general manager, Michael Wood, said the digital elevation model would be an ‘invaluable’ tool.
“We started work on it in 2005 when we realised that, although there are a lot of flood-prone areas across the Richmond, there was not a lot of information,” he said.
“Clearly there was a need for it.”
Funding came through the National Disaster Mitigation Program, and the hard work began.
“The first component was to see what info was already out there,” Mr Wood said.
“It was a bit scary. We realised the data gap was bigger than the data that actually existed.
“The challenge was to combine all the data available and fill the gaps.
“We had aerial photos taken and we did land surveys.
“Then we started the procedure of developing a flood model.
“Luckily, or unluckily, we had floods in 2008 and 2009, which gave us really up-to-date information.
“We used information from the 1974 and 1954 floods as well, because they are the biggest floods that we’ve had.”
After four-and-a-half years of work, the flood model was finished and finally released last week.
It has been delivered to Ballina Shire, Lismore City and Richmond Valley councils, as well as local SES groups and other emergency services.
Mr Wood said the floodmodel would be used to ‘identify high risk areas’, such as Bungawalbin, the Tuckean swamp and Lismore downs.
This will be particularly useful for councils in determining development applications.
“We can start making some really firm, informed decisions,” he said.
“This also models the impacts of global warming in the Richmond River area.
“It is certainly the largest flood model on the NSW eastern seaboard.
“The Richmond floodplain covers 1000 square kilometres, so it is really important for us to have something like this.
“It will provide authorities with information about where it floods and when, how deep the water will get and what the impacts will be.
“The North Coast is an attractive area and lots of people are moving here.
“At least 5000 people live on the floodplain already.
“Yes, there are lot of high risk areas, but it is good for us to know about them.
“Every time we have a flood I am surprised by how much water we get on the Richmond floodplain.
“This model will show the best places for people to live. Awareness is a big thing. We now have a strategic approach, which is important.”
The model has an accuracy of plus or minus 26cm and a confidence factor of 95 per cent.