In a joint media statement WaterNSW and the Murray-Darling Basin Authority said the works would include installation of a temporary coffer dam upstream to separate the inlet from the broader Torrumbarry weir pool to allow the structure to be dewatered for repair.
WaterNSW Executive Manager Operations Ronan Magaharan said the regulator had demonstrated ongoing structural concerns since 2014.
“We’ve had ongoing monitoring on the KP inlet regulator and our recent dam safety inspections have shown elevated risks of a potential piping failure, so it’s necessary that we take the structure offline for repair.
“Procurement is under way for the design and construction of a temporary coffer dam that we estimate will be in place by early next year.
“There is no immediate risk to the community, however it is important that we act now to maintain the integrity of the structure and the Torrumbarry weir pool,” Mr Magaharan said.
Wakool Rivers Association and Koondrook-Perricoota Alliance member John Lolicato said the regulator had been nothing but a problem since it was completed and opened in 2014.
“Even before it was constructed, community members voiced their concerns about the location on the outside of a sweeping bend with lower country in close proximity, making it difficult to access for maintenance in a flood event,” Mr Lolicato said.
He said even before, commissioning problems were beginning to show, culminating in excessive movement of concrete and steel doors.
“Operators have not been able to open all the doors in case they couldn’t close or reseal them.
“Now that increasing leakage rates due to piping have been identified, the potential of a complete failure of the regulator has community members upstream and downstream very concerned.
“Loss of the Torrumbarry weir pool would have an immediate disastrous effect on irrigators, stock and domestic water users and others further downstream with potential flooding.
“To be told it could take up to six months to install a temporary (band-aid) coffer dam is an insult — that time frame doesn’t even include works to rectify the situation.”
Mr Lolicato said in recent times there was an almost identical need to construct an emergency coffer dam in the region at the Yallakool regulator, which was completed in a matter of days by a local contractor.
Local landholder Malcolm Starritt said the regulator was very close to his own property that backs on to the Perricoota Forest.
“There have been quite a few issues and third-party impacts since construction and we hope WaterNSW repair the regulator as a soon as possible.
“All river structures need repairs but it is surprising it needs such essential repairs when the regulator is not that old,” Mr Starritt said.
The Koondrook-Perricoota Forest is an extensive river red gum and woodland forest covering approximately 33,750ha along the Murray River south-west of Deniliquin.
The regulator was built to enable flows of 2000 ML/day out of the Barbers Creeks system and 1000 ML/day out of the Thule Creek system downstream of the forest boundary while minimising impacts on landholders.
MDBA general manager assets Angus Paton said the KP regulator was important to control Murray River flows to periodically flood and dry the Perricoota and Koondrook forests.
“The MDBA will continue to work with Basin governments to plan and prioritise the forward budget necessary to maintain, repair and replace priority structures, such as the Koondrook-Perricoota inlet regulator,” Mr Paton said.
The time frame for remediation of the inlet regulator itself is still to be confirmed and subject to funding and approval by the Ministerial Council.
Updates will be provided via the WaterNSW website and through the MDBA’s River Murray weekly reports.
