Option G2 (Reach 2 & 3)

Extended Stopbank Retreat: Stopbank retreat on Environment Canterbury and privately owned land. 

This option builds on Option G1 by extending the proposed stopbank alignment along the edge of an old river terrace through privately owned land. For both Option G1 and Option G2, new flood protection vegetation would be planted and allowed to establish before the existing stopbank is lowered or removed. This staged approach helps maintain flood resilience during the transition.

• Note: We will publish the map/s for Option G2 following further discussion with relevant landowners.     

Pros

• Increases flood-carrying capacity in this section of the river.
• Reduces constriction created by the existing stopbank alignment.
• Creates a wider flood corridor, allowing floodwaters to move more freely during large flood events.
• Provides greater room for the river to operate naturally.
• Supports long-term flood resilience by moving flood protection further from the river.
• Enables establishment of new flood protection vegetation before the existing stopbank is lowered or removed.
• May provide environmental benefits through expanded riparian vegetation and habitat creation.

Cons

• Requires use of privately owned land and may affect existing land uses.
• May require land acquisition, easements, or other property agreements.
• Could impact farming operations, property access, drainage, and infrastructure.
• Higher implementation costs than shorter retreat options.
• Longer planning and delivery timeframes due to landowner engagement and property requirements.
• Requires ongoing management and maintenance of new flood protection vegetation.
• May result in changes to the landscape and how surrounding land is used.