Did You Know - Weir Gates
Published on 16 October 2026
Did you know that maintaining water in the Warracknabeal weir pool is an important part of managing Yarriambiack Creek?
Council manages the Warracknabeal weir to balance the needs of the community, the town drainage system and changing weather and creek conditions.
The weir pool is an important community and recreational asset. Maintaining an appropriate water level also helps retain water in the creek through the warmer summer months.
Following the 2011 flood, the weir was upgraded from a single undershot gate to eight gates, with additional floodways provided on either side to increase the amount of water that can pass through the weir area.
Why are the weir gates maintained at around 1.5 metres?
Under normal conditions, maintaining the weir gates at approximately 1.5 metres provides a suitable creek level without adversely impacting Warracknabeal's town drainage system.
The floodways on either side of the gates are set at approximately 1.55 metres and 1.60 metres. If the creek rises above its normal level, these floodways provide additional capacity for surplus water to pass through.
This arrangement allows Council to maintain water in the weir pool while providing additional flow capacity when creek levels rise.
Does a 1.5 metre creek level stop the town drainage system from working?
Under normal conditions, no.
Warracknabeal's stormwater system drains towards Yarriambiack Creek. The town's drainage and flood mitigation infrastructure includes flap valves on priority stormwater pipes and culverts to help manage the interaction between the creek and the drainage network.
Maintaining the weir at approximately 1.5 metres provides a suitable normal operating level while allowing the town drainage system to function as intended.
Why can water still build up in streets after very heavy rain?
All town drainage systems have a limited capacity.
During short and intense rainfall events, rain can fall faster than the drainage system can carry it away. When this happens, water may temporarily build up in low-lying streets and other areas.
This does not necessarily mean that the creek is too high or that the drainage system is not working. Once the intensity of the rainfall reduces, these areas will generally begin to drain as capacity becomes available within the drainage system.
It is also important to recognise that local stormwater flooding caused by intense rainfall is different from riverine flooding caused by rising levels in Yarriambiack Creek.
Why doesn't Council simply keep the creek lower?
Keeping the creek unnecessarily low would reduce the amenity and recreational value of the weir pool and make it more difficult to maintain water in the creek through the warmer and drier summer months.
Council therefore aims to maintain a suitable creek level when conditions allow, while remaining prepared to respond to changing weather and upstream creek conditions.
What happens when significant rainfall or creek flows are expected?
The weir is actively managed and monitored by Council.
Council monitors:
- weather forecasts;
- Yarriambiack Creek levels;
- upstream flows and gauge information; and
- developing rainfall and flood conditions.
Where conditions indicate an increased risk, Council can adjust the management of the weir accordingly.
For riverine flooding, upstream creek information can also provide advance warning of flows moving towards Warracknabeal, assisting Council and emergency services with preparedness and response.
In Summary
The Warracknabeal weir is managed to achieve a practical balance between maintaining the weir pool, allowing the town drainage system to operate and managing changing creek conditions.
A weir gate level of approximately 1.5 metres is suitable under normal conditions, with the adjoining floodways at approximately 1.55 metres and 1.60 metres providing additional capacity for surplus water to pass through.
During very intense rainfall, temporary ponding may still occur when rainfall exceeds the capacity of the town drainage system. This water will generally drain once rainfall intensity reduces.
Council continues to monitor weather forecasts, upstream flows and Yarriambiack Creek levels to ensure the weir and creek are managed appropriately.