At its core, data science is the art of extracting knowledge from data. Our team uses data science to discover patterns, make predictions, and contribute to solving real-world problems using data.
DrownBase™ plays a pivotal role in shaping water safety strategies.
The database is New Zealand’s authoritative record of all drowning incidents since 1980 and water-related hospitalisations since 2003.
Expansion of our data capabilities in our Data Science & Insights team is powering up DrownBase™ and making sure the data we collect is available and supporting every decision we make.
Through our enhanced data capabilities, we have identified clear patterns of over-representation in drowning statistics across specific demographic groups, activities, and environments. For example, Auckland, with the region’s growing population, continues to account for the highest number of overall drowning fatalities.
The basics of DrownBase™ in 1980 were not set up to meet 21st century needs. Maturing the system to be fit for data science takes both time and precision.
Basic details of who, where, when, and how people drowned is critical for statistics. But broader information that may help inform why is not historically recorded with each drowning.
Extensive work is underway to ‘tag’ every drowning since 1980 to strengthen our data analysis. But it sure isn’t an overnight job!
Tagging involves manually adding subject specific details to 45 years of drowning data (total of 4,567 drownings* since 1980). Subjects are correlated with details already in DrownBase™, police reports, and coroner’s reports using ‘tags’ such as alcohol and other drugs, if the person was walking, swimming or fishing alone, or if a lifejacket was available and correctly fitted.
This extensive tagging process is fully in place for 2025 drownings. Retrospective work is prioritising drownings from 2015-2024 to further strengthen our data analysis and ability to create insights from data.
*total as of 24 July 2025
If you have a data request not covered by publicly available information, please email us: wsnz@watersafetynz.org.nz
We need to prioritise requests based on our capacity.
Drowning information is entered into DrownBase through information received from The New Zealand Police and The Coroners Court.
New or changing information over time means drowning numbers adjust.
A drowning can be recorded on the day the person died, or many months after the drowning.
Every three months, we receive information from Coronial Services on deaths found by the coroner to be a provisional drowning.
Final findings can, at times, be many months or years after the drowning incident.
In early 2025, a full audit to reconcile all recorded drownings in DrownBase™ and drownings recorded in the National Coronial Information System database was completed. This work adjusted some annual drowning totals over the past 30 years.