Evaluation of engineering solutions to protect Cairns from coastal inundation due to storm surge and sea level rise

O'Donoghue, Grant (2022) Evaluation of engineering solutions to protect Cairns from coastal inundation due to storm surge and sea level rise. [USQ Project]

Text (Project)

Download (13MB) | Preview


Cairns is a very low-lying city that faces an uncertain future due to the threat of inundation from cyclonic storm surge and climate change induced sea level rise. The first objective of this study is to identify engineering technologies to protect the city. The second and main objective is to evaluate seawall alternatives and identify the best seawall solution to construct along the Cairns Esplanade. The main objective of this project was achieved by dividing the project into three tasks: (1) detailed review of literature to identify protective seawall technologies around the world; (2) shortlisting of identified technologies based on specific requirements in Cairns; and (3) evaluation through an Analytical Hierarchy Process.

After evaluating various types of seawalls against multiple criteria including aesthetics, water and wave resistance, durability, foot print and sustainability it was determined that a curved, vertical concrete seawall was the best choice for the Cairns Esplanade. This option best fits in with the requirements to protect the city from coastal inundation whilst also maintaining the Esplanade’s position as a premium tourist and social destination that is central to Cairn’s continuing economic prosperity. It was also determined that construction of the seawall should occur as part of a broader project involving reclaiming and raising land and hardening infrastructure. As the project would need to be completed in stages over an extended period a temporary flood wall solution was also evaluated. The NoFloods barrier tube was identified as a very adaptable temporary solution to fill gaps whilst awaiting completion of the permanent wall. The NoFloods barrier tube is easily stored and can constructed very quickly with little manpower just prior to a cyclone impacting the city.

The city already regularly floods during king tide events and narrowly escaped catastrophe in 2011 when a cyclonic storm surge arrived at low tide. The risk to Cairns is severe and action to implement the recommendations of this report need to be taken immediately.

Statistics for USQ ePrint 51881
Statistics for this ePrint Item
Item Type: USQ Project
Item Status: Live Archive
Faculty/School / Institute/Centre: Current – Faculty of Health, Engineering and Sciences - School of Engineering (1 Jan 2022 -)
Supervisors: Manalo, Allan
Qualification: Bachelor of Engineering (Honours) (Civil)
Date Deposited: 19 Jun 2023 05:45
Last Modified: 20 Jun 2023 01:13
Uncontrolled Keywords: storm surge; sea level rise; engineering solution
URI: https://sear.unisq.edu.au/id/eprint/51881

Actions (login required)

View Item Archive Repository Staff Only