About this project
Following unprecedented levels of flooding over four declared natural disasters in the Tenterfield LGA, the banks of Tenterfield Creek suffered scour and embankment failure in multiple locations. During the 2022 flood events, embankment and creek bed scouring led to embankment failures and sediment was deposited in the creek bed causing blockage of flows and inhibiting fish passage.
Tenterfield Shire Council needed to remediate and stabilise the damage along two sections of the creek in order to prevent further embankment failures and to protect Council assets including a shared path adjacent to the creek. GeoLINK were engaged as part of the Tenterfield Creek Stabilisation Project which focused on:
- ensuring the safety of the community who use the facilities.
- reducing the ongoing maintenance requirements.
- increasing the resilience of the creek during flood events.
Extensive flood damage
Severe damage occurred in two sections of the creek, which were the priority for the project.
- Millbrook Park
The bank was undermined to a point where the shared path that runs along the creek bank was at risk of failing. The undermining resulted in sections of the path being within two metres of the creek creating a safety risk for the community members that used the path. The damage sustained to this side of the bank was also impacting the opposite bank as the path of the water changed. If damage was to continue there was the possibility of the opposite bank failing, impacting the adjacent New England Highway. - Rotary Park
A section of the creek bank failed and slumped into the creek. This caused a blockage in the middle of the creek which was diverting the water further into the bank. The result was major undermining and destabilisation, causing a major safety hazard for users of the park especially for the nearby playground.
Restoring Tenterfield Creek
It was important that solutions be comprehensive and that they be able to withstand future flood events. The client expected a number of aspects to be considered when designing solutions:
Millbrook Park
- Remove and re-place existing rock fill.
- Install large rock fill along the Millbrook Park side of the creek. Batter top of bank to the rock fill to a safe grade and restore flow path of the creek away from the opposite bank.
- Clean up and remove weeds from the creek bank. Improve vegetation with natives and flood friendly planting, ensuring that they do not impact the creek flow path.
- Retain and stabilise the existing undermined bike path.
Rotary Park
- Restore the collapsed creek bank. Batter the top of the bank to safe grade and restore the flow path of the creek away from the opposite bank and towards the bridge.
- Clean up and remove failed vegetation from the middle of the creek.
- Clean up and remove weeds from the creek bank. Improve vegetation with natives and flood friendly planting, ensuring that they don’t impact the creek flow path.
GeoLINK finds workable solutions
GeoLINK designed vegetated rock fill embankment stabilisation and rock riffle bed control structure to stabilise the creek. Achieving environmental outcomes such as improved fish passage and revegetation of the creek with endemic native species, also needed to be achieved. Our civil and environmental engineering teams prepared the design, with assistance from our Botanist who developed a site specific revegetation species list.
Recovery works underway
Works are currently underway to complete the design, with the rock riffle already completed and rock fill to embankments partially completed. Remaining works include topsoil infill to rock voids and revegetation using suitable endemic native species.
Natural disaster environmental recovery
As a multi-disciplinary consultancy, GeoLINK is well placed to provide environmental solutions in flood and natural disaster recovery. Our in-house expertise extends across environmental, engineering, planning and design disciplines, providing a comprehensive approach to difficult recovery projects.