Not waiting for a rainy day...
With a flood emergency management plan ready to be implemented, government representatives took to the Wilsons River by boat on Monday to inspect the damaged flood levee in the CBD while discussing options for fixing it.
Richmond Rive County Council floodplain services manager Michael Wood said, if a flood were imminent, within two and a half hours a 75 cubic metre pile of rock and gravel could be moved into place to shore up a subsided area of levee wall behind Newtrain on Club Lane. The rock would then be capped with a geo-fabric covering to stop it eroding.
Mr Wood said, as Lismore was a flood city, an emergency management method such as this was needed.
“It’s not a long-term solution and if it does flood, the town will still be evacuated by the SES,” he said.
The damaged area of the levee wall is situated in a position where the flows from both the Wilsons River and Leycester Creek catchment areas impact on the wall. It is thought that the levee wall sustained the damage during the last flood when the strong flow from Leycester Creek pumped water onto the site for three or four days.
“Floods are dynamic things – if it was just the flow from the Wilsons River catchment, it would not have been a problem,” Mr Wood said. “Any redesign for the levee will take this into account.”
While a decision has not yet been made as to how the levee will be fixed, Mr Wood said a technical review committee had examined several options proposed by external consultants, the Snowy Mountains Engineering Corporation.
“The consultants have completed a geo-technical study which proposed several different options for the best way forward,” Mr Wood said. “We have decided on the two most viable options. Now we have further investigations to do to see if we need an amalgamation of the two repair options and we need to look at funding options too.”
Mr Wood said that the federal and state governments were supportive but that they had given no timeframes as to when work could be undertaken to get the levee back to its original flood design.
Mr Wood said that the levee had already paid for itself as it had successfully kept the last two floods out of the CBD.
“It saves the town and businesses money in not having to clean up the damage after a flood,” he said.
Mr Wood also expressed concern that the federal government’s axeing of environment programs could potentially exacerbate the effects of flooding as future funding for riverbank rehabilitation would be affected.
“The work done by the Wilson River Landcare Group restoring sections of the river bank is in stark contrast to other areas downstream where erosion has caused the bank to fall down,” he said.