Climate Change and Stormwater and Wastewater Systems

Coastal drains and pipes    
combined with climatic change,    
need thought and action.    

We know climate change is happening and we know stormwater and wastewater systems are vulnerable. What we don’t know is how these impacts will unfold over varying places and times. This discussion paper provides an overview of our current knowledge, and outlines priority research areas to help adapt our stormwater and wastewater systems for a changing climate. The paper draws on a range of expert input, including academia and Crown Research Institutes, the public and private sectors, and specifically water service providers and consultants. Research priorities are: to understand direct and indirect impacts, to identify adaptation opportunities within redevelopment and retrofit, to explore solutions to reduce dependence on legacy delivery mechanisms, and to identify potential improvements in stormwater risk management.

The asset value of stormwater and wastewater assets in New Zealand is well over $20 billion. This includes 24,000 kilometres of public wastewater networks with more than 3,000 pumping stations, and over 17,000 kilometres of stormwater networks. Much of it, however, was not designed for the challenges climate change will bring, from sea level rise to the predicted changes in precipitation frequency and intensity.

“The way climate change is predicted to affect our stormwater and wastewater will have a considerable impact on many aspects of NZ life, including health, disaster resilience, drinking water, ecology, and transport, not to mention how flooding or infrastructure failure will impact on communities,” said Professor Iain White, Professor at Waikato University and a co-author of the Deep South National Science Challenge report Climate Change and Stormwater and Wastewater Systems.