Thames protection and resilience project
Thames coastal protection
Work on design concepts for the protection of Thames is now underway, following project work indicating that $1billion in assets are at risk over the long-term from the effects of flooding and storm-surge associated with sea level rise.
Work to protect Thames from coastal flooding and future effects of sea-level rise continues to progress, with stopbanks confirmed as the preferred option for the town’s foreshore.
The protection of Thames is a high priority for our district, after the Shoreline Management project showed that $1 billion in assets in the township are at risk over the long-term from hazards associated with sea-level rise.
A public meeting held in June 2024 presented various concept designs for protection against a half metre of sea-level rise, and a one in one-hundred-year storm. This level of storm is becoming more frequent along our coastline, and puts Thames at significant risk of flooding.
After taking on board public feedback from the meeting, the project’s governance team confirmed stopbanks will be constructed where space allows along the Thames foreshore. The stopbanks will generally follow the existing footpath, with an expected height increase of approximately 1.4 metres. In narrow areas with limited space, for example behind Pak’n’Save, a wall or sheet-pile solution will be required..
“Everyone involved in the project is also keen to explore additional nature-based solutions that will offer another layer of protection to our town,” said Project Lead, Amon Martin. “These solutions include things like shell banks, oyster islands and chenier ridges, which could bring a range of benefits, including as habitats for birds.”
Meanwhile, Richmond Villas Retirement Village has proposed partnering with TCDC to deliver the section of stopbank protection associated with its property. The proposed partnership includes Richmond Villas leading the engineering, design and construction process, and covering all associated costs. It’s hoped construction on this section can begin early next year.
A workshop on projet progress will be held in August 2024 for Councillors, to be followed by a public meeting. The meeting will provide an update on project work to understand fluvial, or river, hazards and risks to Thames. The project team also expects to have more information to share on the costs associated with protection construction.
Background
Protection was the preferred adaptation pathway for Thames confirmed by community consultation during the Shoreline Management Pathways project. The three-year project examined the risks to the entire Coromandel coastline from the effects of sea-level rise. Specific actions to manage those risks have now been assessed and ranked, with work to protect Thames among the top priorities.
Have a look at our Shoreline Management Pathways project pages to find out more about this process, including information and maps all of all our coastal communities around Thames-Coromandel district, including Thames.
A governance group to progress the Thames protection work met for the first time in February 2024, made up of representatives from our Council, Ngāti Maru and Waikato Regional Council. A further meeting is taking place at the end of July 2024.
“We know that Thames is especially vulnerable to storm surge and flooding associated with sea-level rise, putting around $1 billion of assets in our township at risk,” says our Mayor Len Salt, who is chairing the Thames Protection and Resilience Governance Group.
“Thames is the economic nerve-centre of our district, home to the bulk of the Coromandel’s service provision, maritime industry, healthcare and business infrastructure. It’s our duty to the entire region to ensure Thames is resilient, and able to grow, for generations to come.”
Royal HaskoningDHV is working on design options to protect the township against coastal inundation for a 1% AEP storm over the next 100 years. An earlier feasibility study showed the main challenge associated with protecting Thames is the required cost and scale of any defensive structures, as many locations are low-lying.
Design work will include full hydrodynamic modelling, and joint probability analysis of coincident coastal and fluvial flooding events. The governance group notes that it will be important that any protection structure connects with other stormwater and river management work.
Funding for the design work, and ensuing community consultation on design options, is allocated through 2023-2024 Long Term Plan, with funding for the construction of protection yet to be determined.
“We’re going to come up against some big costs, but those need to be assessed against the value of what’s at risk,” says our Mayor Len Salt. “We’re facing up to these challenges head-on, and doing the forward-thinking, groundbreaking work that’s required, rather than just hoping the issues somehow go away. It’s a multi-generational vision and long-term action plan.”
For more information visit our Shoreline Management Pathways project page.