The likelihood of water quality issues is typically higher over the warmer months. Basin rivers and storages are nutrient rich and conditions remain favourable for blue green algae outbreaks. In the lower Darling (Baaka) there is still a risk of low dissolved oxygen levels.
Summary of key water quality issues
Water quality in the Murray–Darling Basin is monitored by individual Basin state governments. Specific water quality alerts are issued by respective states.
- Low dissolved oxygen: The risk of low dissolved oxygen conditions will increase with prolonged hot and dry conditions. In the lower Darling (Baaka), dissolved oxygen levels generally remain near or above critical ecological thresholds, with adaptive management actions being undertaken to maintain or improve dissolved oxygen levels as required. Low dissolved oxygen levels are also being recorded immediately downstream of Hume Dam. This can occur when Lake Hume becomes seasonally stratified (layered) with poorer quality water released from the deeper levels of the lake. Adaptive operational responses are being utilised to mitigate this risk when it occurs.
- Blue-green algae: There is currently a risk of blue-green algae across most parts of the Murray–Darling Basin, particularly in New South Wales. For the latest information on blue-green algae alerts, contact the relevant state government contacts via the Getting information about current algal blooms page of our website.
- Elevated Salinity: Some areas are seeing elevated salinity levels.
| Location | Algal blooms | Acid sulfate soils | Blackwater | Elevated Salinity | High turbidity | Low dissolved oxygen |
| Coorong | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lower Lakes | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (below Lock 1) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Waikerie to Lock 1) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (SA border to Waikerie) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Lock 10 to SA border) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Euston to Lock 10) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Yarrawonga to Euston) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Possible |
| Murray (Hume to Yarrawonga) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Likely |
| Murray (upstream of Hume Dam) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Edward–Wakool | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murrumbidgee (Upper) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murrumbidgee (Mid) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murrumbidgee (Lower) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lachlan (Upper) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lachlan (Lower) | Likely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Wimmera–Mallee | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Campaspe | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Avoca–Loddon | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Goulburn–Broken | Likely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Ovens | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Kiewa | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lower Darling/Baaka (Menindee to Burtundy) | Likely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Menindee Lakes | Almost certain | Unlikely | Unlikely | Unlikely | Unlikely | Possible |
| Barwon–Darling | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Upper Macquarie–Cudgegong | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lower Macquarie–Castlereagh–Bogan | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Namoi | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Gwydir | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Border Rivers (including Moonie) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Condamine–Maranoa | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Culgoa–Balonne–Narran | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Paroo | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Warrego–Nebine | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |