Option F

Upgrading the existing stopbank network

This option considers upgrading the existing stopbanks, keeping the existing alignment the same (likely with a wider footprint), and increasing the height. Engineered erosion protection and strengthening measures such as rock protection and groynes would be required to increase resilience.

Option F: Upgrading the existing stopbank network

Pros

• This option minimises impact to private property as it follows the existing alignment
• Stopbank upgrades are likely to be required in some sections regardless of any alternative option selected
• Minimal impact on proposed developments and existing activities

Cons

• No backup protection if floodwaters overtop or erode the stopbank
• A higher stopbank allows the river to carry more water, which means better protection in most circumstances but potentially greater impacts for nearby properties if the stopbank is damaged during an extreme flood
• Extent of strengthening could be significant as erosion can occur anywhere along the stopbank system
  
  

Note the options included here are for the part of the river that extends from the Ōkūkū confluence to Rangiora Railway Bridge. We will share design options for downstream areas later in 2026. You can add comments directly to these options or give your feedback via the give feedback section of the page.

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