Climate change and stormwater

Stormwater management is recognised by the Ministry for the Environment as a local government service that is potentially at risk from climate change and may need adaptation.

Stormwater management is recognised by the Ministry for the Environment as a local government service that is potentially at risk from climate change and may need adaptation.

In regions where the frequency and intensity of extreme rainfalls are projected to increase, the possible impacts of climate change include:

  • Increased surface and stream erosion followed by deposition of sediments in receiving environments
  • Flooding at site, local and regional scales
  • Failure of stormwater treatment devices during high flow events leading to by-pass and / or flushing of contaminated water
  • High wet-weather hydraulic loads and bottle-necks in stormwater and sanitary sewer networks due to inflow and sewer infiltration - these can lead to local inundation and overflows of untreated wastewater

Summer warming and drying can also pose problems such as increased temperature and reduced flows in streams and estuaries. 

How to adapt to the impacts of climate change was the subject of the Climate Change and Urban Impacts research programme. The programme created a tool box to help central and local government reduce the risks associated with climate change to the urban environment and its infrastructure, through development of a science-based risk assessment process and identification of opportunities for adaptation.

Find out more about the Climate Change and Urban Impacts programme

Find out more about the Urban Impacts Toolbox

Tools in the toolbox tools demonstrate how to deal with the specific needs of each stage of the process and are illustrated using case study examples from New Zealand including wastewater and stormwater management in Auckland.

Case study examples

In addition to the toolbox, we can work with the NIWA national climate centre, to help assess your future stormwater management needs. For more information, please contact [email protected].

More information about our national climate centre

More information about our climate change research: the CliVar (Climate Variability and Change) pages

Climate change and stormwater. Credit: NIWA
You can also download the Urban Impacts Toolbox Handbook as a PDF.