The Impacts of Climate Change on Stormwater and Wastewater Systems

Much of New Zealand’s stormwater and wastewater infrastructure is vulnerable to the risks associated with a changing climate, including sea-level rise or increasing extremes of rainfall and/or drought. The nature of existing stormwater and wastewater systems mean that they will be significantly impacted in a wide variety of ways including the increasing occurrence of compounding hazards. For example, many systems discharge to low lying areas, and it is these coastal and riverine locations that are most at risk from flooding associated with increasing rainfall intensity compounded with rising sea levels and changing groundwater levels.

This paper presents findings from Deep South Science Challenge research project into the economic, environmental, cultural and social impacts and implications of climate change on New Zealand’s stormwater and wastewater systems. In addition to identifying impacts and implications, the study identifies regional priority areas, and develops a series of guiding principles for managers.