A Council assessment has found that nearly 70 per cent of the stormwater network in the oldest part of Mullumbimby is at a high risk of failure, highlighting the urgent need for an assessment of the network across the entire Shire.
The report, commissioned by Council, will be tabled at the Water, Waste and Sewer Advisory Committee at its January 30 meeting.
It has found that the stormwater and sewerage mains in the centre of Mullum, and areas immediately south, have suffered significant deterioration and have not been sufficiently maintained.
As a result, 69 per cent of the stormwater network and 41 per cent of the sewer network in the oldest parts of Mullum have either a high or very high risk of failure.
This could result in properties being flooded, pipes collapsing, or the collapse of pavements and road surfaces in some places owing to sinkholes.
So what’s the cost?
The report found that replacement and rectification works to the tune of $1.09 million were required immediately.
There were also 38 mains or maintenance holes that could not be assessed because of ‘obstructions’ or because they ‘could not be found’.
Sewerage works valued at $515,000 were due to go out to tender late last year, and are estimated to be completed by the end of the current financial year.
However, there is currently no budget for the $580,000 worth of stormwater works.
The Council report said a request to fund these works was being submitted to the Transport and Infrastructure Advisory Committee.
Duncan Dey, a member of the Water, Waste and Sewer Advisory Committee, which is due to receive the report on January 30, said the committee was being asked to ‘recommend nothing to Council and to just note the report’.
The former councillor said he hoped the committee will instead recognise the high level of deterioration of the two systems, built between the 1940s and 1960s.
Additionally he is wanting to ‘recommend expediting the current estimated expenditure to Council, recognising that this may be only the beginning.’
He said that ongoing assessment and maintenance is necessary over the life of the systems and that deterioration would worsen over time, requiring eventual replacement.
Council staff noted that the poor condition of sewerage and stormwater in Mullumbimby highlighted the fact that other portions of the network across the Shire may also be in ‘particularly poor condition’.
‘It is proposed, in future, to replicate the [assessment] approach that has been adopted for this portion of the Mullumbimby catchment, and apply it to the remainder of the network in a prudent and efficient manner,’ staff said.
This was due to begin in the current financial year, with the assessment of catchments in Byron Bay and Ocean Shores, which had been identified as high risk.
However, staff said that owing to a lack of funding for the stormwater network, the gravity sewer main assessments would have to be undertaken in isolation without stormwater.
The report said, ‘When considering the degree of urgent rectification works that were required following the Mullumbimby assessment, it is likely that the budget of $5m over five years will be insufficient to adequately manage the sewer network.’