Preparing for Sea-Level Rise through Adaptive Managed Retreat of a New Zealand Stormwater and Wastewater Network

Abstract

Due to sea-level rise and associated compounding climate-related hazards, managing stormwater and wastewater services to exposed coastal communities will become progressively harder for local governments. Responsible agencies must determine whether such networks can continue to be adapted/protected over time to retain levels of service, or whether retreat may be the only viable adaptation option.

Involving key local stakeholders, we use dynamic adaptive pathway planning (DAPP) to identify thresholds for stormwater and wastewater services adaptation and retreat options to develop a comprehensive and area-specific retreat strategy for coastal Lower Hutt, New Zealand. We present this process in a pathway form that can be communicated spatially and visually, helping to make retreat a more manageable adaptation option for water agencies, and the communities they serve.