Flood mitigation for Latrobe, Tasmania
Client: Latrobe Council, Tasmania
Location: Latrobe, Tasmania / Australia
Date: 2017 - 2024
Reducing the risk of flooding in a town centre
Background
In June 2016, the town of Latrobe in northern Tasmania was significantly affected by flooding from the Mersey River. The devastating event led to significant property damage and the loss of one life. Communities and businesses need protection to boost resilience and safeguard property and lives against rare, intense rainfall events and floods.
Solution
Entura was engaged by Latrobe Council in 2017 to conduct a flood analysis and develop options to protect the Latrobe township from future flooding at a level experienced in June 2016. We examined the potential for a levee to protect the town from Mersey River flooding as well as the enhancement or addition of detention storage in Kings Creek, and delivered a report to Latrobe Council in 2018.
Since conducting the early flood studies, Entura’s involvement has continued across 8 years, encompassing preliminary design, surveying, geotechnical investigations, environmental values assessments and a preliminary environmental management plan , approvals support, and detailed design in partnership with construction contractor BridgePro and consultants Rare Innovations and Tasman Geotechnics.
(Image: During the project's construction.)
The flood solution includes earth and concrete levees to protect the town centre against a flood from the Mersey River like the 2016 event, as well as flooding in Kings Creek that runs through the town. The levee is 1 to 3 m high and runs 1.5 km around the edge of the Mersey River. The solution also involves gates, pumps and a large culvert to redirect Kings Creek during a flood into 'Sammys Drain' then the Mersey River.
At every stage our team rose to the project’s many challenges. Entura’s flood modellers developed a range of innovative solutions and, with our client, determined an appropriate way forward. Our surveyor identified controls to improve the boundary identification that had long been missed by others. Our geotechnical engineers gave insight into the ground conditions and our dam engineers designed the civil works and supported plans for the safe operation of the infrastructure. Entura’s planners were also involved in the project, achieving a dam works permit as the levee is considered a dam in Tasmania.
Flexibility and successful collaborations with other consultants (Rare Innovation and Tasman Geotechnics) and with the construction contractor BridgePro brought innovation and delivered value to the client. Entura’s flood modellers and designers collaborated with others to support the innovation offered by the contractor, providing further assessment using 3D CFD analysis of large box culvert over 300 m long with a tapering side overflow inlet weir.
Services provided
- flood modelling
- preliminary and detailed civil design
- surveying
- geotechnical investigations
- environmental values assessments
- approvals support
Outcome
Entura’s flood management and civil design expertise, coupled with our flexibility and positive partnerships, have provided Latrobe Council with end-to-end support and a successful solution. The flood protection works have now been effectively completed, providing the township of Latrobe with a levee and diversion culvert and lasting protection against floods.
