Dry horrors - Councillor says Hawke’s Bay’s next drought likely to be region’s worst

Parched dry hills north of Napier during the drought of 2019 to 2020. A councillor is warning it could happen again, and be even worse this time. Photo / Warren Buckland

The realities of drought might be far from the minds of most in Hawke’s Bay.

But as weather patterns shift, the region needs to prepare for dry horrors ahead, a councillor is warning.

Hawke’s Bay regional councillor Jock Mackintosh says in a talking point for Hawke’s Bay Today on Friday that the next drought could be the driest the region has ever seen.

Mackintosh says the realities of climate change, and the release of his council’s regional water assessment, means now is the time to renew the discussion about water storage, given the assessment paints a stark picture of looming water shortages.

Storage, in the form of dams, has long been seen insurance in a drought that can top up low summer river flows, but it has been controversial in the region ever since the failed Ruataniwha Dam proposal.

Hawke’s Bay Regional Council acting science manager Dr Kathleen Kozyniak said it was too early to say if the region will get a drought this summer, but the developing El Nino pattern did mean there was a heightened risk.

“As usual, we’ll be closely monitoring weather patterns and the status of the region’s rainfall and soil moisture and sharing information through our website and monthly state-of-the-environment reporting,” Kozyniak said.

National Institute of Water and Atmospheric Research (Niwa) meteorologist Ben Noll said the shift in the climate-driving weather patterns from La Nina to El Nino would play an important role in weather and climate variability.

“This idea of abnormal dryness or drought could come as a surprise to people. However, in saying that, we are seeing a major flip in our climate drivers,” Noll said.

Niwa’s latest season climate outlook covers September to November and warns of below-average rainfall and “unusually long dry spells for several regions”.

“We are picking an elevated risk for drier-than-normal conditions in the east of the North Island, which includes Hawke’s Bay,” Noll said.

He said the month of August for Hawke’s Bay had already had an amount of rainfall 50 per cent below the normal average, and late September and early October had indications of drier weather trends, but there was still a high amount of moisture in the ground from rainfall earlier in the year and there was no imminent threat of a drought.

“We are not seeing, from a hydrological perspective, any meaningful impacts just yet, but when you start to potentially string together a couple of months of reduced rainfall approaching the summer season which, climatologically speaking, is the driest time of year, then we do need to be aware of this risk,” he said.

He said the key components that dictate whether a location is in drought were a lack of rainfall, a soil moisture deficit sustained over a period of months and evapotranspiration, or the rate at which water in the ground leaves the ground to enter the atmosphere due to sunshine, warm temperatures and wind.

Hawke's Bay regional councillor Jock Mackintosh has warned in a talking point of the potential for drought with climate change and El Nino, and says community-scale methods of storage (i.e. dams) make sense as a way to combat the effects. Photo / Warren Buckland

Water Holdings Hawke’s Bay say their proposed Makaroro Storage Scheme, the reworked modern version of the failed Ruataniwha Dam, would store 100 million cubic metres of water if it was ever built.

Hugh Ritchie, a director of Water Holdings Hawke’s Bay, said climate change was happening and creating drastic issues, including the potential for reduced rainfall.

“Storing it when you have got it for when you haven’t got it - it is just fundamentally sound logic,” Ritchie said.

But Tom Kay, a freshwater advocate for Forest & Bird, argues that damming a river is the worst thing you can do for the local ecosystem.

“All the natural stuff that should happen in a river ecosystem, like sediment moving down and gravel coming to the coast to restore the beaches, which then protect us from sea level rise, is hindered by a dam, not to mention that fish need to move up and downstream.”

He said New Zealand should instead follow a nature-based approach for water storage and retention, including planting forests on hillsides, restoring wetlands and making more room for rivers.

James Pocock joined Hawke’s Bay Today in 2021 and writes breaking news and features, with a focus on environment, local government and post-cyclone issues in the region. He has a keen interest in finding the bigger picture in research and making it more accessible to audiences. He lives in Napier. james.pocock@nzme.co.nz.