Flood waters continue to flow down the Barwon-Darling catchment area and on Thursday WaterNSW reported the flood peak at Wilcannia – it may reach around 11m – is likely within the next one to seven days.
Higher than expected inflows into the linked Menindee Lakes have seen the weir gates lowered once again so water inflows can be more controlled.
“ Over the past week as the higher flows have reached the Menindee Lake system, the Main Weir gates have been reinstated to maintain the target height of around 9.6m at the Menindee town gauge and limit further inundation,” said a WaterNSW spokesperson on Thursday.
“The airspace generated from storage operations over the past several months is now being utilised to capture the higher inflows.”
The Bureau of Meteorology’s current flood warning says Wilcannia may see a peak flow of about 43-46GL a day and WaterNSW is expecting at least a further 1300-1700 GL to arrive to Wilcannia between now and the end of February.
There is no risk of flooding for the town itself.
“Observations over the past week have indicated total inflows to the Menindee Lake system are now potentially being influenced by the connectivity of the main river channel and Tallyawalka creek between Wilcannia and Menindee,” the spokesperson said.
“This occurrence is likely contributing to unaccounted water and additional inflow to the lake’s storage above the previously forecast peak inflows of 43-46GL/d.”
The government body points out, “due to the dynamic nature of the current flood event and the terrain on which water is passing, the quantification of the total inflows is extremely variable”.
At Menindee Lakes on Thursday there was approximately 294GL of airspace still available, says WaterNSW – the amount that can still flow in before the Lakes would overflow – with controlled flows aimed at keeping that level steady as flood waters continue to arrive.
“The current releases are expected to continue throughout January 2023 and given variability in inflows, higher releases may be considered if the total unaccounted inflows exceed the current forecast volumes,” said the spokesperson.
