The independent review examining the factors that contributed to flooding after Cyclone Gabrielle has been submitted to the Hawke’s Bay Regional Council.
Initiated by the Hawke’s Bay Regional Council, the independent review aimed to understand the circumstances and factors leading to the flooding. It covered flood management schemes, council decisions during the cyclone, and the viability of these measures. The review panel consisted of experts in resource management, engineering, and law.
The review panel – comprising Dr Phil Mitchell, Kyle Christensen, and Bernadette Roka Arapere – acknowledged public input and thanked participants for their contributions.
Cyclone Gabrielle resulted in one of New Zealand’s most significant flood events, overwhelming flood defences and inundating unprotected floodplains throughout the region, impacting communities, businesses, infrastructure, and cultural sites.
The review highlighted several issues, such as inadequate planning for events that exceed the capacity of existing flood defences, underestimation of flood risks, and insufficient warning and evacuation procedures.
The panel noted that more than 100,000 people were at risk due to the lack of practical evacuation solutions prior to flooding.
During the event, the council faced challenges including discrepancies between forecasted and actual rainfall, failure of telemetry systems, loss of water level and rainfall measuring equipment, and staff being overwhelmed by the event’s scale. The council said these issues hindered its ability to provide accurate and timely flood forecasts and advice to Civil Defence.
The panel emphasised the need for central government funding to rebuild and enhance flood management infrastructure. It stressed the importance of collaboration between local and central government, communities, mana whenua, and businesses to improve future flood risk management.
The review provides a framework for improving the region’s flood resilience, offering 47 recommendations across seven key areas:
Christensen said legacy flood management infrastructure needs significant upgrades.
“It needs to be substantially upgraded and re-imagined to provide a safe, healthy and resilient river, floodplain, and overall catchment system,” he said. “Any new stopbanks need to be designed in a way that provides predictable and manageable performance during events that exceed their capacity.”
Mitchell noted that the Regional Policy Statement lacked clear direction on managing flood hazards, allowing development in high-risk areas.
“The fact that there were relatively new housing developments in areas of known flood risk suggests that lessons from the past have not been learnt, and development has been allowed in high hazard areas,” Mitchell said.
The panel concluded that maintenance levels likely had a limited impact on the flood event’s consequences but recommended re-surveying river channels, managing gravel buildup, and maintaining river mouths.
The panel further highlighted the inadequacy of current funding models for flood management and stressed the need for central government support. The members recommended a shift to more sustainable and equitable funding mechanisms.
Te Uru Kahika, representing New Zealand’s regional and unitary councils, welcomed the report.
Michael McCartney, regional CEOs group convenor for Te Uru Kahika, said understanding and learning from such events is crucial for future preparedness.
“Some of the 47 recommendations in the Independent Flood Report released yesterday are in line with other recent reports. In some areas implementation of improvements is already underway, while other recommendations will need fresh consideration before decisions on next steps,” he said.
