Alexandrina Council remains committed to delivering a long-term solution to the ongoing flooding issues in Ashbourne. As previously communicated, we are progressing through the complex planning and design stages to ensure the right infrastructure is delivered for the benefit of the community.

Project Progress

Since our last update, and after careful assessment, Council has selected Concept Design Option 2 as the most effective long-term solution for Ashbourne’s flood mitigation needs. Refer to Ashbourne Stormwater Mitigation Web Page for detailed drawings.

Concept Design Option 2 is comprised of two (2) Key strategies.

Strategy 1

Manage Bull Creek stormwater to keep the water away from developed properties in the high risk flood prone areas. This includes Levee Banks on the East/South side of Bull Creek, High Level overflow paths and a raised section of Kirkham Road which is an integral part of the Levee bank system. This includes Levee Banks on the East/South side of Bull Creek, High Level overflow paths and a raised section of Kirkham Road which is an integral part of the Levee bank system.

Strategy 2

Collect and direct Bull Creek Road, Kirkham Road and Ashbourne Road West Stormwater through town via a dedicated stormwater pipe system. This will also include side of road stormwater collection improvements and an improved swale and pipe system along Kirkham Road.

Community Engagement and Design Development

Council has worked closely with affected property owners to gather feedback and incorporate it into the design, wherever possible, without compromising the integrity of the flood mitigation system.

• Detailed site surveys have been completed, including on-ground inspections and direct engagement with some landowners.
• All field data and suitable community input has been integrated into the detailed design process.
• Detailed Engineering design is now underway, including a review of flood mapping to ensure the project continues to meet the 1% Annual Exceedance Probability (AEP) flood mitigation target.

Challenges

Council has encountered some challenges in securing in-principle agreements for stormwater easements on certain properties, which generally apply to the proposed levee and stormwater detention elements. We are currently reviewing our options under the Local Government (General) Regulations 2013 to progress the establishment of these easements where necessary. If an alternative process is required, this may delay construction of the mitigation infrastructure.

Looking Ahead

As the Ashbourne Stormwater Mitigation Project moves forward, Alexandrina Council is focused on several key next steps to ensure its successful delivery:

• Securing approvals and easements: Council is working to obtain the necessary permissions and formal easement agreements from property owners and to seek concept approvals from Landscape SA. Council will meet with each property owner to explain their specific easement requirements as part of the formal easement process. Where formal easement agreements are challenging, we will explore other options under the Local Government (General) Regulations 2013. We aim for this to be completed by the end of February 2026.
• Detailed Designs – Strategy 1 Levee Banks, Kirkham Road and Bull Creek Road stormwater systems: Part of the design phase is to complete the Environmental, Cultural and Geotechnical investigations, slope stability and seepage checks for where the levee banks and gabion walls and stormwater systems along Kirkham Road will be constructed. Once this data has been received and analysed, the detailed engineering designs and cost estimates can be completed.
• Detailed Designs – Strategy 2 Bull Creek Road stormwater system: Due to some easement negotiations still not finalised, this part of the stormwater mitigation project is impacted but being worked through. We are aiming for the detailed designs to be completed by the end of November 2026.
• Committed Funding: Funding has been approved by Council for the Strategy 1 works and part of the Strategy 2 Works. Refer to the Annual Community Plan and the A2040 Strategic Delivery Plan.

We are planning on commencing construction of the Kirkham Road swale, stormwater outlet pipe to Bull Creek and a section of Bull Creek Road kerbing this financial year.

The remaining Strategy 1 works are planned to be completed over the ensuing two (2) years. The remaining Strategy 2 work will commence as soon as additional funding is available.

• Securing additional funding: Whilst some funding is in place to keep this project moving, Council will actively seek financial support through government grants and funding programs to help cover the cost of construction and ensure the project achieves its primary aims. This includes exploring partnerships and external funding opportunities to reduce the financial burden on ratepayers.
• Keeping the community informed: Regular updates will be provided to keep residents informed about progress, timelines, and any impacts. We’ll ensure clear communication before any works begin near homes or roads. At a minimum we will provide quarterly updates.
• Working together: Community support, cooperation and involvement are essential. We thank residents for their ongoing engagement and feedback, and we’ll continue to listen and respond as the project progresses.

Visualising Flood Scenarios

Explore how proposed Strategy 1 is designed to manage flood events.

The top maps show Ashbourne with existing infrastructure.

Bottom maps show Ashbourne with proposed Strategy 1 works. See map legend for colour coding of modelled flood water depth.