In summary:
- Council noted the flood scoping studies for Tallygaroopna and Katandra West at its April Council Meeting.
- Tallygaroopna: Minor flood risk (1% chance annually) for a small number of properties. Recommendations include planning scheme updates and drainage improvements.
- Katandra West: Low flood risk, no further studies recommended.
- Ongoing drainage maintenance crucial for both towns.
- Public consultation will be held for flood studies in both towns, with reports available for public comment on Shaping Greater Shepp in early May.
Both studies were managed by staff from Council, Goulburn Broken Catchment Management Authority (GBCMA) and State Emergency Service (SES), and were undertaken to obtain community information about previous floods, including individual experiences often verified by photos and flood lines on private properties.
The Tallygaroopna study confirmed that there is likely to be one per cent annual exceedance probability (AEP) of above floor flooding at Tallygaroopna but limited to a small number of properties. The flooding should however be relatively benign with one per cent AEP depths and velocities generally limited to 0.25 metres and 0.3 metres per second, respectively.
Tallygaroopna has been affected by flooding on six separate occasions between 1919 and 2012, yet there are currently no flood overlays in the planning scheme for the town. The GBCMA 2018 to 2028 strategy recommends that improved mapping be prepared for Tallygaroopna in the short term.
Potential future infrastructure mitigation measures which could be undertaken in Tallygaroopna include:
- Improvement of the south side bypass drain.
- Allowance for additional rural runoff from south of Victoria Road to discharge into the Slaughterhouse Road diversion drain.
- Upgrades to the existing railway and highway cross drainage structures.
The report highlighted the importance for Council, Goulburn Murray Water and VicTrack to each undertake ongoing flood drainage management activities to ensure that flooding impacts are minimised. The study provides Council with the following recommended future actions:
- Include a Land Subject to Inundation Overlay (LSIO) in the planning scheme to reflect the findings of the report.
- Impose minimum floor level controls to development in Tallygaroopna to 300 millimetres above the one per cent AEP flood height.
- Update the Council Municipal Flood Management Plan to reflect the findings of the study.
- Update Council’s Emergency Plan to reflect the findings of the study.
- Work with the GBCMA to formalise a trigger height for the control of inlet gates on Congupna Creek using a newly installed creek flood height gauge.
- A flood study followed by a floodplain risk management study utilising hydraulic modelling in the longer term.
The study recommends that future updates by the SES of the ‘Local Flood Guide – Tallygaroopna’ reflect the relevant findings of the report.
The GBCMA 2018 to 2028 strategy recommended a flood scoping study also to be undertaken for Katandra West, which has been affected by flooding on six separate occasions between 1919 and 2012.
The findings in the report found that the 2012 flood event was the most severe. The impact of this event was likely exacerbated by infrastructure failing during the event. No houses are known to have flooded to above floor level in this event. Therefore, the flood risks to existing development at the Katandra West Township can be described as low.
The scoping study does not recommend further flood studies or floodplain risk management studies be undertaken, finding that no flood mitigation measures are required for Katandra West. The report highlighted the importance for Council and Goulburn Murray Water to undertake ongoing flood drainage management activities instead.
It is recommended that the areas inundated in 2012 be included in the LSIO within the Greater Shepparton Planning Scheme. The study recommends that future updates by the SES of the ‘Local Flood Guide – Katandra West’ and Council Flood Emergency Plan reflect the relevant findings of the report.
The development of both flood studies involved considerable consultation with the community including the formation of a Community Reference Group, community drop-in session and survey. Both the Tallygaroopna and Katandra West final reports will now be put out for public consultation, before being provided to Council for consideration.
Mayor, Councillor Shane Sali, said the flood scoping studies are important for Greater Shepparton as they help the region better prepare for future flood events.
“The development of the flood scoping studies is critical for our region, as they increase public awareness of the impact of storm events and flooding within the Tallygaroopna and Katandra West communities,” he said.
“The studies have defined thresholds and identified areas which have previously been inundated with flood water within these communities, which will better improve emergency response management.”
The reports will be released for consultation in early May via the Shaping Greater Shepp website.
