A small amount of additional water is being released from Goulburn Weir over the next couple of days to improve water quality in the lower Goulburn River.
This release of 1,500ML/day will not cause any flooding issues in the Goulburn River and downstream.
Goulburn Broken CMA CEO Chris Norman said the CMA had been working with other agencies to monitor water quality in the Goulburn River after heavy rain washed leaf litter and debris into a number of creeks that flow into the river.
“Between Friday December 1 and Sunday December 3 up to 200mm of rain fell across parts of the catchment,” Mr Norman said.
“This resulted in high inflows from Seven, Pranjip and Castle creeks into the lower Goulburn River. This debris-rich water, combined with the warm air and water temperatures we experienced recently, has caused the levels of oxygen in the water drop.
“Fortunately, the oxygen levels did not drop suddenly to the very low levels we saw earlier this year, which caused a blackwater event that led to fish deaths in a section of the Goulburn River near Shepparton. Oxygen levels have now steadied to acceptable levels.
“But to be on the safe side, particularly as temperatures increase again over the next couple of days, we have been working with Goulburn-Murray Water, the Victorian Environmental Water Holder and the Commonwealth Environmental Water Office to get approval to use a mix of environmental and water quality flows to help maintain water oxygen levels. This will see flows from Goulburn Weir of 1,500 ML/d over the weekend which will then slowly step down to the normal base flow level of 800-900 ML/d by the end of December.”
Goulburn Broken CMA, Goulburn Valley Water’s Waterwatch team and partner agencies will continue to closely monitor water quality along the lower Goulburn River and its tributaries.
Flows in the lower Goulburn River peaked at 23,000 ML/d at Shepparton on December 5 and are currently around 9,500ML/day and falling. This is well below minor flood level.
This short You Tube clip provides more information about the causes and effects of blackwater: http://bit.ly/2AH7l2o