The Ministry for Cities, Environment, Regions and Transport (MCERT) has released an updated version of a widely used rainfall dataset.
The High Intensity Rainfall Design System (HIRDS), developed by Earth Sciences New Zealand, helps planners and engineers estimate how much rain could fall at a location, over different durations, and how frequently rainfall of that magnitude might occur.
It supports decisions ranging from sizing culverts and stormwater drains to designing flood protection and other major infrastructure.
Following the July announcement of free access to HIRDS, a version 5 update has been released.
“MCERT funding once again means the tool and underlying datasets can be accessed free of charge, including for commercial use, under a creative commons (CC BY) license,” the Ministry said in a statement.
Commercial use of the dataset, including for engineering design and consultancy for public infrastructure, previously attracted a charge. Â Â
HIRDS version 5 includes around 10 more years of rainfall observations. This means more recent extreme rainfall events are included in the analysis.
Previous versions assumed rainfall patterns remained stable over time. Version 5 instead accounts for observed changes in extreme rainfall.Â
Access to up-to-date rainfall information helps councils, engineers and infrastructure planners understand extreme rainfall and plan for the future.
The work builds on MCERT’s broader efforts to make natural hazard information more accessible. HIRDS data also informs flood hazard information used in the New Zealand Flood Map. Â
The Ministry said the New Zealand Flood Map will provide a trusted picture of flood hazards across the country. It is a key component of the National Adaptation Framework, the Government’s long-term and strategic approach to climate change.
