A small amount of additional water has been released from Goulburn Weir to improve water quality in the lower Goulburn River.
The release of 1500Ml/day during two days last week was initiated following heavy rain earlier this month.
Goulburn Broken CMA chief executive officer 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 to 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.’’
Mr Norman said the authority had worked 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.
The flow has now stepped down from the 1500Ml/day flow to the normal base flow level of 800 to 900Ml/day 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.