Note: this is a shortened version of the entire case summary. The full version of the Kawatiri Business Case summary as well as questions and answers pertaining to the case are available for download at the bottom of this page.
Key recommendations
The Kawatiri Business Case outlines a mix of Protect, Avoid, Adapt and Retreat options and priorities, the full range of solutions that are needed to make Westport more resilient to future floods, both now and in the future. This is known as the P.A.R.A. framework.
Protect
A Technical Advisory Group (TAG) was established by the West Coast Regional Council (December 2021) to identify preferred flood risk mitigation structural and nature-based protection options. Seven options were considered by the TAG, factoring extensive climate change scenarios (specific detail can be found in the Kawatiri Business Case).
The favoured Westport flood mitigation scheme is as follows:
1. Rock lining repair works for bank protection near O’Conor Home (two sections) and Organs Island. (This work is being progressed regardless of whether coinvestment can be obtained).
2. A combination of concrete wall, single board walls and double earth filled walls, with the use of each being selected to best suit site specific circumstances.
3. Embankments and walls with alignment, heights, and other design parameters to reflect the results of modelling and hydrological effectiveness research carried out by Land River Sea Consulting Ltd, and design considerations put forward by G & E Williams Consulting Ltd.
4. Extension of the flood risk mitigation at Carters Beach to the east to include houses along Schadick Avenue and to provide additional flood risk resilience to additional houses and the critical lifeline utility services provided by the airport.
5. Revegetation of a relic Buller River meander near Organs Island.
6. Re-grade the bed of Abattoir Creek to enable more flow to be diverted away from this ‘at risk’ area of urban development.
Avoid
The Kawatiri Business Case:
• Requests a fast-track mechanism for Te Tai o Poutini Plan ((TTPP) the combined district plan for the West Coast) appeals – a special order (or other mechanism) to be enacted that allows appeals on the Westport hazard provision of the TTPP to be limited to points of law only.
• Seeks to amend the Building Code for finished floor levels, or to otherwise give flexibility to apply an appropriate standard for the area concerned.
Retreat
The Kawatiri Business Case:
• Recommends the Government resources a development plan for the Alma Road area
to ensure positive community outcomes.
• Proposes that a feasibility study be undertaken in FY 22/23 by Buller District Council, supported by Kāinga Ora and Kānoa, with a view to securing further land parcels in order to sustain a growth zone for Westport that is in a low-risk area.
• Recommends establishing an initial fund of $10m to allow for some local relief for areas that will not be protected by the flood protection embankment such as Snodgrass Rd Area owners.
Accommodate
The Kawatiri Business Case:
• Proposes that the Government fund the secondment of a Resilience Officer, reporting to the Chief Executive of Buller District Council.
• Recommends investing in wave height gauging stations so that modellers can use more reliable wave height and sea level rise information. Currently there is no accurate sea level gauge on the West Coast, nor accurate wave height buoy.
• Proposes that separate provision be made for stormwater infrastructure to remove accumulated local stormwater. These would provide for the removal of the additional groundwater that may accumulate in the lower parts of Westport because of sea level rise.
• Identifies a pathway forward in regards to insurance. The proposals outlined in the Kawatiri Business Case are seen as an opportunity to build confidence that Westport manages risks well, related investment and planning is credible, the community isresilient, and the community is adapting appropriately to the potential effects of climate change.
Further information on the Kawatiri Business Case Summary:
- Full version of the Kawatiri Business Case
- Questions and Answers on the Kawatiri Business Case: QA on Westport Flood Resilience Options
- Questions and answers session with river modelling expert Matt Gardner (video): https://www.facebook.com/watch/?v=1140677439854188
Pictured: River modelling expert Matt Gardner presenting a technical Q&A session on the Kawatiri Business Case
