Responding to Acts of God

The adjacent urban areas of Richmond and Stoke within the adjoining Tasman and Nelson Districts suffered from an extreme rainfall event on 21 April 2013 causing approximately $35 million damage within a few hours.

The rainfall event was calculated to have a 1 in 500 year Average Recurrence Interval (ARI) and thus was far rarer than the 50 or 100 year ARI (2% or 1% Average Exceedance Probability) storms currently considered by most local authority standards and most likely way beyond the reticulated stormwater capacity of any urban area worldwide. Thus this event, while predictable, is beyond human control and often legally considered as “an act of God”. This event followed other recent significant storm events within the region.

Tasman District Council’s (Council’s) response is discussed from multiple perspectives:

• the engineering physical works programme required to restore operational capacity;
• the consenting framework needed to minimise the impact of and on future development;
• the building control safe & sanitary inspections and consenting response;
• the strategic planning response reviewing the questions of hazard and risk posed by future similar events and how Council could improve protection for the community; and
• overarching whole-of-Council considerations.

This event has required a cross-departmental response from Council and has facilitated consideration of a whole-of-Council policy position.