New Reports Contribute to Coastal Hazards Program 2021
18 December the CCC issued their first newsletter on their Coastal Hazards Adaptation Planning Programme. This followed their 3 information sessions in late November / early December. Through this programme, CCC indicated they are wanting to work with communities to start planning now for how they will manage coastal hazard risks over the next 100 years. They are focusing on low lying coastal and inland communities in Christchurch and Banks Peninsula that are likely to be impacted by sea level rise through coastal erosion, flooding, and rising groundwater.
The CCC CHAP(Coastal Hazards Adaption Planning) programme has outlined the procedure for engagement and the 5 areas of the city that will be engaged with in the initial stages. The first of these will be Lyttleton/Mt Herbert. As part of this on going work an updated Coastal Hazards assessment has been done by Tonkin and Taylor. This 'Analysis Scoping Milestone Summary Report' from Tonkin + Taylor will outline the proposed methodology and approach to Coastal Hazards in the area.
Another piece of work in this program is the Aqualinc Report ‘Impacts of Earthquakes and Sea Level Rise on Shallow Groundwater Levels’
The Multi-Hazard Study will inform decisions on long-term floodplain management strategies for the lower reaches of the Avon, Heathcote and Styx Rivers, and Sumner. The Avon catchment is being progressed in priority to other catchments to help inform the Otākāro Avon River Corridor design. The other catchments will follow.
The purpose of the groundwater assessment was not to accurately define the shallow groundwater hazard at a local scale, but to provide a high-level assessment at the citywide scale. It is not sufficiently detailed to identify individual property risks therefore will have no impact on LIM wording. Any future consideration of a groundwater response would be part of long-term planning and will require additional investigation and policy direction from Council.