A national assessment of the drinking water infrastructure deficit in New Zealand by territorial authority and sociodemographic characteristics

The quality of drinking water reticulation networks is central to ensuring the provision of safe water. We conducted a national assessment of public drinking water reticulation condition in New Zealand (NZ) derived from information on pipe material and age and investigated regional and sociodemographic variations in the reticulation network. In total, 30.7% of the 57,174 km of drinking water pipes in NZ were in poor or very poor condition, while 18.5% were past their life expectancy. We identified wide variation in the proportion of pipes in poor or very poor condition amongst Territorial Authorities (TAs) and between areas of varying socioeconomic deprivation within TAs. Using nationally consistent data, our findings suggest that the current drinking water infrastructure deficit in NZ may be larger than previously estimated. Our results also highlight potential challenges to TA-based amalgamation of water services under the new legislation.