Ashbourne Stormwater Mitigation Project

Thank you to the 40+ people who attended the community meeting on the 30 May 2024 and provided valuable feedback on the presented concept Stormwater Mitigation solutions.

Your feedback, and suggested changes, are being reviewed and modelled to ensure we achieve our goals of providing 1% AEP (1:100 Year) event Stormwater protection.

The initial concept of installing a Flood Barrier has been replaced with the potential of raising a small section of Kirkham Road to provide continuity to the Flood Levee Bank, eliminating the need to erect the proposed flood barrier during emergencies. The initial design and flood modelling of this change is in progress, along with transitioning the Stormwater Mitigation solutions from the Modelling Stage to the Concept Design stage. This will enable us to obtain cost estimates for each proposed solution. This is a complex task, and we aim to have the cost estimates back from the engineers by the end of July 2024.

The improvements to the Levee Bank along Bull Creek require a detailed survey to obtain accurate and specific information. This will commence on the 8 July 2024, and all affected land owners have been advised accordingly.

We hope to have further updates on the mitigation options over the next three weeks.

We have also uploaded the Ashbourne Flood Map Timeline Video that was within the Presentation at the Community session.

We invite you to attend a community meeting on Thursday 30 May 2024, 5pm – 6pm at the Ashbourne Community Hall.

Following the Ashbourne aerial surveys earlier this year, a Southfront Stormwater Management Engineer will present flood modelling and solution recommendations, along with Council representatives.

There will be time for discussion and feedback.

Further details to come, but we kindy ask for you to mark this in your calendar.

Further to community feedback discussions, and in consultation with our engineering consultants, we have increased the Ashbourne aerial survey area which will delay the survey start until next Tuesday 27 February. We are advised that completion of the survey will be Saturday 2 March.

The additional survey area is shown in below in BLUE.

Alexandrina Council has committed funds in the 2023-2024 Budget towards improving stormwater management in Ashbourne with the aim of reducing potential flood impacts to residents.

As part of this project with the aim to reduce potential flood impacts to residents, Council’s specialist stormwater management consultants have organised for aerial surveying to be performed on Thursday 22 to Saturday 24 February 2024.

This survey is fundamental in collecting catchment and runoff area measurements for stormwater flow and volume calculations to enable accurate design of stormwater infrastructure.

Aerial Survey Map (within red line area)

This survey will be performed by Drone Hire Australia Group (DHA) using the latest Drone Lidar technology. Lidar stands for Light Detection and Ranging, which is remote sensing technology that measures distances to assist in the creation of detailed 2D/3D models of the environment.

The Drones will not be taking photos, just taking digital measurements. DHA are approved by the Civil Aviation Safety Authority (CASA) for this type of activity.

On the Monday to Wednesday leading up to the Aerial Survey, the specialist Drone team will be door knocking on properties that will have the drone flying over the houses, to explain what they will be doing.

During the Drone operation and survey on Thursday through to Saturday, please keep clear of the Drone Launch and Landing platform and allow the Drone Operator to concentrate on the drone operation by keeping clear and not disturbing them.

Should you require further information, feel free to contact Council’s Team Leader Civil and Transport Assets on (08) 8555 7000 or alex@alexandrina.sa.gov.au.

Council would like to continue to notify community members of activities related to this project. To confirm the best method for contact, we ask if you could fill out the short survey to confirm contact details.

Visit here to fill out the short survey: https://mysay.alexandrina.sa.gov.au/embeds/projects/91771/survey-tools/102894

Alexandrina Council has committed funds in the 2023-2024 Budget towards improving stormwater management in Ashbourne with the aim of reducing potential flood impacts to residents.

To facilitate this project, civil surveying contractors from Andrew & Associates undertook a detailed survey in the Ashbourne and Bull Creek areas from Tuesday 7 November 2023 through to Friday 10 November 2023.

The contractors collected geographic information and land levels for contour maps as well as identified trees, fence lines, buildings, and underground services necessary for designing pipework and stormwater systems. Traffic conditions didn't change and the surveyors were visible along sections of Bull Creek Road, Kirkham Road, Christina Street, and parts of Bull Creek.

Council communicated directly with any landowners where the surveyors required direct access to specific private properties.

Image below: The following map details the areas surveyed. The survey work occurred between the green lines.