Updated Coastal Hazard Assessment released

Today we've released an updated Coastal Hazard Assessment for Christchurch and Banks Peninsula as part of the Urban Development and Transport Committee agenda.

This assessment is the most up-to-date information we currently have about how our coastal and low-lying communities might be affected by coastal flooding, erosion and groundwater, and how this might change over time with sea level rise. It will help us predict risks, and will support sound planning discussions with Ngāi Tahu rūnanga and communities across the Christchurch district about how we can respond to these risks.

The Coastal Hazards Assessment has been developed by Tonkin + Taylor and has gone through a rolling technical review by a principal coastal hazards scientist at Jacobs to provide confidence in the integrity of the information.

We have previously undertaken other coastal hazards assessments. However, important new data has recently become available, including information on sediment supply, groundwater and high tides, which has implications for how we identify areas prone to coastal hazards. This assessment also includes areas which previously have not been assessed. It covers the entire coastline of the Christchurch District, extending from the Waimakariri River mouth in the north to the entrance of Te Waihora (Lake Ellesmere) in the south.

Read the Coastal Hazard Assessment. 

The Coastal Hazards Assessment is being used to inform two important work programmes at the Council – the Coastal Hazards Adaptation Planning Programme and the Coastal Hazards Plan Change. The Coastal Hazards Plan Change is about managing new development, changes of use and subdivision proposed in the future. Reducing risks to existing land use activities and development will be considered through the Coastal Hazards Adaptation Planning programme

The release of the updated Coastal Hazards Assessment signals the start of a citywide conversation on coastal hazards. Pending Urban Development and Transport Committee approval, on Friday 8 October we’ll be releasing two documents for feedback:

• The Coastal Adaptation Framework, which is our proposed approach for adaptation planning with communities.
• A ‘first step’ Issues and Options discussion paper for the Coastal Hazards Plan Change which discusses the issues that we are facing and why we need to change the District Plan, and sets out a range of options for how the District Plan could manage the risks associated with these hazards.

Feedback on both documents will run until Monday 15 November. 

On Friday 8 October we’ll also be launching an online interactive map that lets you adjust the timeframes and sea level rise levels to see how areas might be impacted by coastal flooding, erosion and groundwater.

We’ll be in touch again on 8 October when engagement goes live, with more information on how you can have your say. In the meantime, if you have any questions please get in touch. 

We'd also love to hear from you if you have a  community meeting planned during the engagement period (8 October – 15 November) and would like us to attend.

Ngā mihi

The Coastal Hazards Project Team

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