The reliable supply of safe drinking water is vital for the health of human populations. Despite this, there is no consistent nationwide spatial dataset of water distribution zones (WDZ) for Aotearoa New Zealand (A-NZ). The purpose of this data article is to describe the development and validation of a consistent nationwide dataset of WDZ across A-NZ. We obtained spatial data from all 67 district and city councils through: 1) information requests between 2021 and 2023; 2) the Ministry of Health and; 3) the Institute of Environmental Science and Research. Data were modified to improve the spatial accuracy of the WDZ using auxiliary data on the building footprints (Land Information New Zealand) and the drinking water reticulation (WSP & councils). We estimated the population served by each WDZ through spatial linking to meshblock-level data provided by Statistics New Zealand (meshblocks are the smallest administrative geographic unit in A-NZ). The dataset will be useful to provide insights into the extent of the publicly-owned drinking water assets in A-NZ and is essential for the accurate exposure assessment in epidemiological research investigating the impact of drinking water quality on human health.