Hawke's Bay's climate future revealed - droughts, floods and more hot days
Photo:
Supplied / Dawson Bliss
The first climate change assessment report for Hawke's Bay has been released, revealing an increased risk of ex-tropical cyclones, droughts and flooding.
It was commissioned by the Climate Action Joint Committee, made up of local and regional council representatives and tangata whenua leaders, and shows a broad range of climate change risks the region faces, and the likely impacts.
The region is far too familiar with the effects of climate change, having suffered a severe drought in 2020 and 2021, followed by
the 'wettest year on record' in 2022
, and then the
devastating Cyclone Gabrielle in 2023
.
Committee chair Xan Harding said for the first time, this report presents a full range of climate risks for Hawke's Bay.
"One of the key findings from this work is the significant level of variability and gaps in our climate datasets across the region. We have a foundation to work from with this report, but there is more to do so we can all be confident we are making climate risk-informed decisions based on consistent data that is as complete as possible."
The Hawke's Bay region covered 14,200 square kilometres, and 80 percent of that land was hill country or mountainous terrain. Often referred to as the 'fruit bowl of New Zealand', it was one of the top wine capitals of the world and grew 60 percent of the country's apples.
The lives of the region's 185,400 residents were expected to be impacted by climate change, which the report predicted would substantially alter the environmental conditions of the region in the coming decades.
Councils were working on a number of flood resilience projects, including a $176 million multi-year investment to allow communities severely affected by Cyclone Gabrielle to stay in place while new community-scale flood infrastructure was built. It was also looking at reshaping two major flood schemes in the Heretaunga Plains and Upper Tukituki catchments, and reviewing smaller flood schemes.
The report provided more information on the hazard datasets used for the assessment, including event likelihoods (Annual Exceedance Probability, or AEP) and how the modelling took climate change into account. A 1 percent AEP was an event that had a 1 percent chance of occurring each year.
The report broke the climate change risks down into the region's different districts.
Flooding in Napier, February 2023.
Photo:
NZDF / supplied
Napier City was 105 square kilometres in size, with a population of 64,695. It had extensive coastal areas of housing, including beaches and Ahuriri Estuary, and was bounded by rivers to the north and south.
A long-awaited strategy to tackle coastal erosion
was released last year
. It identified 'trigger points' in four areas where more than $34m needs to be spent to protect homes.
The Hastings District covered 5229 square kilometres and had a population of 85,965. Present day river and rainfall flooding risk (2 percent AEP) was the most severe hazard for the Hastings District, with 39 percent of commercial properties and 11 percent of residential properties
exposed and 48 percent of the population at risk of isolation.
The Central Hawke's Bay District covered 3333 square kilometres and had a population of 15,480. The biggest risk was from river flooding, and had been identified as the most severe hazard influenced by climate change.
Water security was a high priority for the district, with the controversial Ruataniwha Dam being [https://www.rnz.co.nz/news/national/556408/campaign-launched-against-controversial-ruataniwha-dam-in-hawke-s-bay
resurrected and rebranded] under the government's fast-track legislation.
Ruataniwha Dam opponents pictured in 2024.
Photo:
Supplied
Wairoa township.
Photo:
Pool / NZME
Wairoa had a land area of 4077 square kilometres and a population of just 8826, half of whom lived in the township.
Wairoa River posed a large threat, flooding many times in the past. The most recent was in June 2024, when about 400 properties
were inundated
.
Funding had been approved for a $70m flood protection scheme, set to begin this year, which would create
spillways for the Wairoa River to be diverted into in future floods
.
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