Following the events of the 2022 Australian floods, Griffith City Council have decided to reallocate funds in the 2022/23 budget to address unprecedented water levels at Lake Wyangan.
The water level in Lake Wyangan has reached a record height due to continual rainfall and additional runoff from the catchment to the north. Resulting in flood damage to two residential houses, Jones Road causeway and associated buildings and infrastructure around the foreshore of the North Lake.
At the Extraordinary Council Meeting held on 10 January 2023, Council resolved to divert funds from the Lake Wyangan foreshore improvements fund into a new Lake Wyangan Flood Pump and Pipeline Project. This will enable water to be pumped out of Lake Wyangan into the drainage channel along Slopes Road that eventually drains into the Barren Box Storage and Wetlands system.
Griffith Deputy Mayor, Glen Andreazza, said this action would allow Council to reduce the water level from around the inundated homes, the Jones Road Causeway and infrastructure on the foreshore of the North Lake.
“Given that Lake Wyangan, both North and South Lakes, are closed catchments there is no natural drainage outlet to allow any water out of the Lakes,” Mr Andreazza said.
“After investigating suitable options, we’ve determined that the only way of extracting water is by mechanically pumping the water to another location using a new pipeline.”
On 4 August 2022 and 14 September 2022 the Griffith LGA, along with numerous other LGAs, was declared a disaster on the basis of severe weather and flooding. Given the emergency nature of the flooding situation and the urgent need to take action to address several issues at Lake Wyangan, the Extraordinary Council Meeting was called in order to deal with the matter.
“In late 2022 we already took steps to pump approximately 1,000ML water into Tharbogang Wetland and water is also currently being pumped into Campbell Wetland,” Mr Andreazza said.
“Murrumbidgee Irrigation has given permission for Council to pump water for a limited period out of Lake Wyangan up to the drain which discharges into Barren Box Swamp.
“Once water has been pumped out, Jones Road will then be assessed to determine the scope and cost of repairs with a view to resuming access to the Lake via Jones Road.
“We anticipate there will be long term benefits from installing this new infrastructure. It will enable future discharge of water from the Lake when opportunities present.”
The proposed pump will provide an output of approximately 20ML per day when operated for 24 hours per day. Around 4,000ML is needed to be extracted out of Lake Wyangan so it is anticipated it will take approximately six and half months of continual pumping to reduce the water level to enable Jones Road causeway to be exposed.
The total estimated cost of the pipeline project is $1.4 million, which will include a new flood pump, 1.5km of high density pipe, assembly and installation, excavation and removal of the old outdated pipe and running costs.