Levee for Ballina? Council reconsiders flood options
A LEVEE for Ballina Island is being reassessed by the council as part of its latest review into the town's flood mitigation strategies.
The assessment of a levee or levees throughout the town was requested to be undertaken by Ballina Shire councillors as part of the council staff's review of its floodplain risk management plan.
Group manager civil services John Truman said the elected council asked for the feasibility of the levee concept to be re-examined in response to community concerns about the use of fill to raise individual allotments.
"One possible alternative to (filling) is whether a levee system could either reduce that demand or remove that demand,” Mr Truman said.
He explained changes to the fill policy over the years has had an "impact on the urban landscape in terms of look as well as drainage issues between different homes at different floor heights and fill levels”.
"The levee would stop that so that's one of the big advantages of the levee,” he said.
But Mr Truman said the possible cost of a levee could put immense pressure on the council and community.
"Incrementally those costs (from filling) then are spread as development occurs where as a levee which the cost of that would essentially be borne by the whole of the community at the one time,” he said.
Mr Truman said the massive engineering feat and cost of a levee proved "completely infeasible” when the council previously assessed the concept.
"The trick for us this time is look at that in more detail to try and find whether there is a technical solution that can be in an engineering sense more affordable and therefore potentially compared more favourably against the existing fill policy,” he said.
He said water redirection and its impact on other towns within the shire would be among the key considerations over the next 18 months as the review takes place.
"If there were feasible options around a levee, certainly one of the issues to examine would be what changes in the rover flood pattern would occur because of the levee, positive and negative,” Mr Truman said.
But he said the levee wouldn't be the ultimate solution to reducing flood impact in Ballina "given the complexity of the issue”.
"It's more likely to be an integration or combination of one or more things,” he said.
Assessments of policy provision for building design such as allowing for stilted housing would be also conducted throughout the review.
Mr Truman said large part of those studies involves "recalibrating the flood model” for more reliable predictions and models to try and then inform the flood mitigation policies.
He said the review marks the council's "continuous on-going process of updating its flood model and policies that are associated with it.”