Water meters could be a part of the future conversation to help Hawke's Bay avoid a water shortfall. Photo / Getty Images
Hawke’s Bay will soon swing on a brutal pendulum between not enough water and too much water all at once if nothing is done about our demand and supply.
Water meters and policies to incentivise industry to move to Wairoa are both now in the conversation to combat a potential 115-million-cubic-metre annual deficit predicted by Hawke’s Bay Regional Council’s Regional Water Assessment (RWA), released today.
After one of Hawke’s Bay’s wettest years on record and the devastating floods of Cyclone Gabrielle, it will be difficult for many to imagine that the region will face decreasing rainfall and water deficits in the near future.
But the worst case scenario foreseen by the RWA is nearly a 115-million-cubic-metre shortfall of water by 2060.
Even a much more modest prediction, assuming the implementation of “significant” water savings and efficiencies (a 1 per cent reduction annually, adding up to nearly 40 per cent by 2060), modelled a shortfall of nearly 25m cubic metres by 2040, increasing to 33m cubic metres by 2060.
Modellers in the report determined that the most likely future scenario sits between the two.
The report presents potential supply and demand solutions to alleviate this pressure, with water meters being one demand-side solution.
“Even without water charges being added, water meters have been shown to reduce water use by making residents aware of how much water they are using,” a report summary reads.
“Charging for water has been shown to significantly reduce water use [in NZ + overseas]. This can be achieved through general, targeted, or differential rates or charging by volume.”
The report highlights the fact that in the Wairoa and Mohaka Districts, in contrast to most of the region, water supply exceeds demand.
“Perhaps policies that promote and support taking industry to water instead of moving water to industry can be an important component of achieving a more enduring regional water balance,” the RWA reads.
The regional council has already invested $1 million in working with Hawke’s Bay’s largest industrial water users to identify opportunities for greater conservation, efficiency, re-use, and collaboration as part of their investigation into demand solutions according to the report.
Supply solutions could include clawing back water allocation, Managed Aquifer Recharge, Community-scale water storage or dams, enhancing wetlands and reusing grey water.
Tom Skerman, formerly of the regional council, worked on the report and told councillors at a meeting today that demand-side solutions would give them “the best bang for [their] buck” in response to a question from Councillor Neil Kirton.
About 5 per cent less rainfall is expected in 2040 and 15 per cent less in 2090 due to climate change according to the report.
Heatwaves (three or more days above 25C) will increase to 10 to 20 days by 2040, and 20 to 60 days by 2090.
Hinewai Ormsby, regional council chairwoman, said the report came as increasingly volatile and extreme weather directly impacted the lives of whānau.
“Most recently, we’ve seen the impact of a cyclone, but it’s not long ago that we faced two years of severe drought. Those weather events are expected to become more frequent and more severe,” Ormsby said.
“We need to find a way to make our region more resilient and that will require some big decisions about how we manage this precious taonga. The RWA provides the baseline data and options to inform those decisions.”
Chris Dolley, regional council asset management group manager, said the RWA was the first report of its kind in New Zealand.
“On the face of it, it looks as though we have plenty of water, with more than 16 billion cubic metres (m3) of rain falling on our region in the 2019/20 year studied, and the region only using 138 million cubic metres of that,” Dolley said.
“The problem is that we don’t have enough water in the drier months when it’s needed most. And in future, we’ll need to leave even more water in the environment to protect our waterways and the biodiversity that relies on them, on top of what we’re already using now.”
Ngaio Tiuka, Ngāti Kahungunu’s environment and natural resources director, said Ngāti Kahungunu had made clear to the council on numerous occasions that they were in favour of a sound and sustainable water allocation framework, as required by the National Policy Statement on Freshwater.
He said that specifically meant phasing out the over-allocation of water and giving effect to Te Mana o Te Wai.
“Te Mana o te wai elevates water in the rivers first not for irrigators. These costly engineering projects use public resources to entrench bad management decisions to essentially continue over allocation and supply water user demands first,” Tiuka said.
He said one natural solution to declining freshwater aquifer levers based on the latest science had been put forward to the HBRC Cyclone Recovery Committee last week.
“Rather than an artificial aquifer recharge proposal and far less costly would be restoring natural aquifer recharge with far more benefits to a wider cross-section of the community,” he said.
Wise Water Use Hawke’s Bay spokesman Dr Trevor Le Lievre said in a statement that the group believes the key findings of the RWA show that the regional council should immediately review and reallocate large water consents.
“The report’s authors are to be applauded for highlighting this legacy issue and for promoting remedies that include both demand reduction, and clawing back large economically unfair and environmentally unsustainable consents,” Le Lievre said.
He said another key finding was that Central Hawke’s Bay (CHB) has the highest water use per capita and the lowest financial return measured by GDP across the region, with $14.33m for every 1m cubic metres of water used.
“If CHB used its water as efficiently as Wairoa our district could be earning around $1 billion additional income each year,” he said.
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
Vi was born Violet Blanche Avison, in Waipawa in 1924.