Reports find Napier flood event unavoidable, but confusion, duplication and delay hampered response
Two independent reports on the Napier flood in November last year found that the intensity and location of the rainfall resulted in unavoidable flooding, but a myriad of issues hampered the city's response.
On Monday, November 9, what has now been reclassified as a one-in-100-year event, as opposed to a one-in-250-year event, hit the city, with more than 240mm falling in the 24-hour period through to 9am the following day.
There were landslips, widespread flooding, 10,000 power outages, 115 dwellings made inhabitable and 173 evacuees.
The capacity of the city’s drainage network was overloaded and particularly felt in the suburbs of Maraenui, Napier South and Pirimai, where 117 homes were damaged beyond repair and many more suffered flood damage.
Flooding was also experienced in parts of Marewa, Onekawa, the Napier CBD, Taradale and Tamatea, with localised landslides on Napier Hill. Thirty-five family groups were provided with emergency accommodation at the Kennedy Park facility operated by Napier City Council, where a small number of family groups remained over six months later.
A hazard report was undertaken by Toa Consulting for Hawke's Bay Regional Council and focused cause and consequences of the event, including the inability to accurately predict where the rain would fall, and the inability of key assets to control drainage and flooding due to the event’s intensity.
A separate Independent Operational Review carried out by Fire and Emergency New Zealand scrutinised the multi-agency operational response by the Napier City Council, Hawke's Bay Regional Council and Hawke's Bay Civil Defence and Emergency Group and raised a list of concerns and areas to improve structures and processes.
While overall there was a good response underlined by the good relationships between the responding agencies in the region, it found there was also "confusion, delays and information flow difficulties" relating to different operating systems and processes being used by the agencies responding to the event.
The review states that the local Fire and Emergency area commander received a warning at 10am, that there was the potential for heavy rain in Hawke’s Bay but these external indicators failed to include mention of Napier City. He advised local brigades of this and began monitoring the weather.
It wasn't until about 4.30pm when they began to receive 111 emergency calls, and the deteriorating weather heightened his concerns, that he contacted the controller of Hawke’s Bay Civil Defence and Emergency Group. This was the first indication the controller had that the rain was causing issues.
An Incident Management Team was eventually formed and at 8.10pm a local state of emergency was declared by Napier mayor Kirsten Wise.
She told the reviewers she would have appreciated quicker support from those leading the emergency response, and she had been prepared to declare a state of emergency earlier.
“She also found that people she was advised who were going to turn up to support the local Incident Management Team did not arrive,” the review said.
It recommended the creation of a common operating platform (COP) that will help ensure everyone is "working together and silos are eliminated".
Other recommendations included appointing a recovery manager immediately embedded in the IMT, adopting the training pathway already developed, creating a roster to ensure an IMT can be activated at any time, even in holiday periods, and providing training for personnel who will be expected to fulfil the Response Manager or Planning Manager roles.
Rick Barker, Chairman of the Hawke’s Bay Regional Council, welcomed the reports and commended the agencies involved in the event for their quick response and strong relationships.
“The Napier flood was an overwhelming event on many levels, taking the community by surprise. It took Napier city’s infrastructure well beyond its designed capacity. However, the response was quick, organised and effective, which is a testament to the strong network of civil defence relationships in Hawke’s Bay,” says Mr Barker.
“There is also room for improvement. In any major event, things go wrong so this is an opportunity to analyse what worked well and what didn’t, to bake in the lessons learned and be ready for any future events,” adds Mr Barker.
Wise also supported the findings of both reports and wanted to ensure the people affected by the flooding were kept front of mind.
“The flooding affected the lives of many in our community, and some are still living with those impacts, so it’s important we learn lessons from this event,” says Mayor Wise.
“The reports provide the opportunities to act on the conclusions, including the potential to coordinate the operation of drainage assets maintained independently by Napier City and the Regional Council.”
She said Napier City’s drainage and flood control assets are designed to national standards, however, the intensity of November’s rainfall event meant that no urban stormwater system designed to these standards would have been able to operate to prevent the flooding that occurred.
Power outages at a number of pump stations and debris in the stormwater network contributed to prolonging the event.
“The intensity of the rainfall in November was far beyond the design capacity or capability of the Napier stormwater scheme. Our council, the network of civil defence and support agencies including Fire and Emergency NZ came together quickly to support our community at the time, and in the months that followed the flood,” says Ms Wise.
“We have an action plan and we are getting on with making changes through what we’ve learnt here.”
The hazard report also acknowledged the good initiative taken by Napier residents with little warning of the severity of the rain and subsequent flooding for the city, meaning the majority of evacuations were self-initiated. The community worked very well together in the wake of the flood, with many offers of help from all over the city and region.
“What we’ll continue to do now is work through the report’s conclusions, such as sharing information and systems between councils where it makes sense to do so, reviewing our asset plans and the complementary operation of our drainage and flood control assets with the Regional Council so that we’re in the best possible position ahead of any future event,” adds Mayor Wise.
