Flood warning issued
BY JULIA ILES and JENNIFER HUXLEY
IF URGENT action is not taken Grafton could face flooding similar to the 2005 New Orleans disaster, according to two former council engineers.
Mike Gorrie and Bill Paterson say that a report recently released by the executive manager of Clarence Valley Floodplain Services, Ian Dinham, reveals 'obvious deficiencies' in the Grafton levee, establishing that the city is not protected from a one-in-100 year flood as believed previously.
Mr Gorrie believes studies undertaken after the 2001 floods revealed numerous low spots in the levee system protecting north Grafton and that water was close to overtopping in some instances.
"The 2001 flood, the biggest one this century (in the Clarence Valley) wasn't considered to be a 1-in-100 ... but it was obvious there were a few low spots in the levee and in some places it was very close to the water overtopping, which is what happened in New Orleans," Mr Gorrie said.
"Levees are made to be even all along but during the 2001 flood the water reached different places, for example, the main flood gauge in Prince Street had a clearance of about 45cm, but along the levee the clearance was 10cm and this shows the levee has sunk a bit ? not uncommon."
Mr Gorrie said fixing the levees would be a small expense. The outlay would help protect Grafton from a devastating flood.
"We're saying bring the levee up to the design height, and it's hard to understand why the Clarence Valley Council is being so complacent about the issue which will only cost about $2 million to fix and in an annual budget of $120 million is petty ? from what you read in the media and other reports, they seem to be busy doing repairs, maintenance and it seems fixing the levee up is a low priority," he said.
"We don't know when it is going to flood ? if it's this week, next month, next year ? but if it happens someone is responsible and people will look to blame."
Mr Gorrie gave as an example Byron Shire Council, when it was sued by residents. The council was accused of not topping up a levee.
Clarence Valley Floodplain Services chairman and Clarence Valley councillor Kerry Lloyd said yesterday emergency remedial action had already been undertaken to fix the identified weaknesses in the levee.
He said council was waiting for the release of results from six floodplain studies being undertaken in the Clarence Valley before deciding on a course of action.
"The delay in large-scale action here is essentially because such action requires in-depth research and large-scale funding, both of which we are working on at the moment. It's not as easy as saying here's the risk, let's fix it. It's a long process," Cr Lloyd said.
"The levee we have in the Clarence Valley was designed and built in the 1970s and the technology we have now just wasn't available then, so while we don't have the 1-in-100 year protection as we thought, the research being done in the six studies will enable us to evaluate our options and ensure we have the best possible flood protection in the long run."
Cr Lloyd said there was a large amount of levee wall to maintain and asked that residents be aware that 'anywhere there's a levee there's a risk'.
He said raising the levee in Grafton could have huge effects down river during a flood, due to potentially large volumes of displaced water.
"People need to understand that levees are designed to be floodproof not waterproof, but I want to assure residents that the council is well and truly prepared, we are not going to walk away from our responsi- bilities," he said.