This update provides an overview on how the Murray–Darling Basin Authority is managing Hume Dam and Dartmouth Dam during the current high flows.
The regular update includes:
- catchment conditions
- forecast rainfall and inflows
- water releases
- planned management for the coming week.
Catchment conditions
For the week of 27 September to 3 October the rainfall for Victoria and southern New South Wales remained largely above average. Soil moisture levels for the upper Murray are slightly lower than last week at 69% but remain above average for this time of year.
Forecast rainfall and inflows
The Bureau of Meteorology is expecting rainfall totals to 10 October to be in the range of
50 – 100mm across the Murray–Darling Basin, including significant falls in the Upper Murray catchment.
The 7-day forecast map is automatically generated and subject to change daily when the models are run.
The Bureau of Meteorology is the best source of information to stay up-to-date with more detailed forecast rainfall and flood information.
The outlook for the next 2 weeks shows a high chance of above-average rainfall. The outlook for the next 3 months shows a similar picture with a high chance of above-average rainfall.
The status of the Bureau of Meteorology’s El Niño–Southern Oscillation Outlook has been raised to La Niña. The Bureau suggests this La Niña event may peak during spring and return to neutral conditions early in 2023. La Niña events increase the chances of above-average rainfall during spring and summer for northern and eastern Australia.
In addition, the negative Indian Ocean Dipole (IOD) event is likely to continue into late spring. A negative IOD event is typically associated with above average spring rainfall for much of Australia.
Snapshot: Dartmouth and Hume
Dartmouth Dam and Hume Dam this week
Flood operations are being conducted at both dams.
Dartmouth Dam is flowing over the spillway. The flow in the Mitta Mitta River will be dependent on the spillway flow plus inflows from tributaries such as Snowy Creek downstream of the dam.
It is likely that channel capacity at Tallandoon will be exceeded in the coming days and may reach minor flood level if a significant amount of rain falls, especially in the Snowy Creek catchment.
Releases from Hume Dam have been held steady over the past week, allowing significant airspace to be generated. The MDBA will continue to monitor the rain as it falls, and the inflow it generates, before deciding whether releases will be increased, decreased or remain steady.
If conditions permit, releases may be reduced to allow a peak from the Kiewa River to pass down the Murray, but this cannot be guaranteed.
The MDBA does not provide flow forecasts during periods of flooding. Please refer to the Bureau of Meteorology.
Are you flood ready?
If you live, work or holiday on a floodplain, be prepared
Develop your personalised flood emergency plan for your home and property
www.ses.nsw.gov.au
www.ses.vic.gov.au/plan-and-stay-safe
All residents can sign up for the Early Warning Network to be notified about Hume Dam release activities during periods of flooding or high releases
www.waternsw.com.au/supply/ewn
Check the BoM website to receive the latest weather and flood information and warnings in your area
www.bom.gov.au/australia/flood
www.bom.gov.au/australia/warnings