Predicted Flood Impact of the Bypass

FLOOD modelling for the bypass predicts a 10 percent increase in water levels on the western side of the bypass, but on the eastern side is expected to remain the same or be improved.

The modeling was presented to the community on Saturday morning by the Roads and Maritime Services, however many residents remain concerned the modelling will be correct and several residents have received letters from their insurers saying they now have to pay flood insurance because of the bypass.

Marcia and Phillip Keast said their insurance has increased and many residents near the bypass have been informed they are now in a flood zone.

“It’s gone from $1,300 up to $3,000 or $4000 for insurance to insure our house,” said Ms Keast.

“We asked the NRMA why and they said ‘bypass, flood, that’s why your premium has gone up’ and we can’t afford it and it’s not just us,” she said.

Philip Keast questioned the disparity between the modelling and their insurance premium.

“How can the RMS be saying one thing and the NRMA be saying another?” questioned Mr Keast.

“I think that is where Council’s flood study falls down because they haven’t got one for a start,” he said.

The flood modeling was based in part on data from the Upper Hunter Shire Council and many questioned if it was accurate and if the current sewerage and drainage structures by Council were adequate.

“I have very big concerns about water, because I know Council studies are not up to what they should be,” said Mr Keast.

“We had 21 ml of rain the other day and the drain that is put in off the Council drain was full it had backed up and would be 400 to 500 metres and it was full back up to my shed and couldn’t get away,” he said.

“It’s not just the water that comes down St Aubins it is the water than comes down Hill Street and further up that way which has to come down past us and the drainage is not big enough to carry the water that comes down.

“Right at the end of St Aubins street is where the water used wot spread out and that’s where it would come down Liverpool Street and went through the culverts, with the road there now it can’t spread out and any water that comes from the eastern side has got to come this way,” said Mr Keast.

The bypass originally included a bridge at Kingdon Street and another at Liverpool Street, but based on impact studies one larger bridge measuring 540 metres will now be in place to ensure water from Parsons Gully can flow more easily.

Within the banks of the bypass there will be large culvert structures between the railway line and the Golf Club to allow better flow from Figtree Gully into Parsons Gully and large culverts at St Aubins.

There will then be a series of smaller cross drainage throughout the bypass.

The modelling indicates that water levels on the western side of the bypass may increase by 10 percent in a flood event, but water on the eastern side would remain the same or slightly less, as the bypass would act as a buffer to those on the eastern side.

It also indicates properties which have not been impacted by flooding before the bypass will not be impacted after the bypass.

There was also discussion about the adequacy of the current storm water system operated by Council and several residents voiced their disappointment that no Councillors were part of the meeting.

Related stories:

• Development Doubted – March 22, 2018
• Draining Issue with Council – February 3, 2017
• Storm Damage Clean Up – January 30, 2017