Science helps us track how native fish, mussels, and other aquatic life respond to water for the environment. It also helps us track water quality and flow in the Namoi Valley.
Lessons learnt
Monitoring, evaluation and research shows us what's working and what's not. This knowledge helps us manage water for the environment in real-time and in the future.
To build this knowledge, we collect data about:
- habitat inundation and water quality
- the condition of the native fish community
- hydrology and flow delivery
Native fish
During dry periods, even small flows in the lower Namoi help native fish to survive. These flows make the river deeper and improve oxygen levels, creating refuge pools for fish.
The number of small freshes has reduced due to river regulation downstream of Chaffey Dam and Keepit dams. Small freshes are small rises within the river channel that increase water depth and connectivity between habitats, and provide a cue for animals to move. It's crucial to use water for the environment to mimic small freshes and support fish populations.
At the height of the 2017–20 drought, our NSW partners and Local Engagement Officers tracked the location and number of habitats in the Namoi and Peel rivers. This data will help us manage the drought's impact on native fish and their habitat in the future.
Connectivity
A pulse of 750 megalitres per day is better than 500 megalitres per day for wetting low-level benches in the Peel River.
Flows of 750 megalitres per day can cause fine sediment to move and be abrasive. But, flows over 1,000 megalitres per day may be necessary to move built-up sediment and algae downstream of Chaffey Dam.
Freshwater mussels
Freshwater mussels like being wet. They rely on permanent river reaches and waterholes. They also rely on native fish to survive.
Freshwater mussels are vulnerable when rivers dry out during long dry periods. Protecting baseflows helps mussels recover from the drought. "Baseflows" is the consistent, continuous flow of water in a river system. It comes from groundwater storage and also surface inflows. These flows provide a baseline or minimum level of water that sustains the river even during dry periods or when there is no significant rainfall.
Floodplain mussels can survive for months in dry conditions, as long as it's cool. River mussels can only survive for a few weeks under the same conditions. If it gets too hot, they may survive for only a few days.
CEWH science
We support several projects through our CEWH science programs.
In the Namoi Valley, we work on these projects with:
- NSW environmental agencies
- the Murray-Darling Basin Authority
- scientists
- First Nations people
- local community.
Flow-MER Program publications
On-ground activities for the Flow-MER Program are underway. Read the Border, Barwon and Namoi science publications containing detailed information on the monitoring, evaluation and research activities planned for 2024-2029, including updates and reports.
You can also visit the Flow-MER website to learn more about monitoring in the Border, Barwon and Namoi Area.