Opinion: Let’s choose our water future before climate change chooses for us

To reduce demand, we need to be more efficient with irrigation and processing, we need to improve our farming practices to retain soil moisture, and towns and cities need to conserve water, says Hinewai Ormsby. Photo / NZME

OPINION:

Hawke’s Bay’s access to water is vulnerable to the impacts of climate change. We need to change the way we value this precious taonga, how we use it and how we ensure there’s enough to go around. And we need to do it soon.

Our region is already feeling the effects of climate change through water. At times, like we’ve seen in the past six months, we’ll have too much, with more cyclones, floods and sea-level rise, and then at times, probably more frequently, we’ll see the opposite, with less rainfall and increasing droughts.

Those impacts will put pressure on our environment, our communities, and our economy.

Hawke’s Bay Regional Council is currently discussing a report with tangata whenua, local councils and key stakeholders that investigates what those climate change impacts could look like in our region in the future and what choices we have ahead of us.

That report will be released in the next few months to kick-start a public conversation about how we secure access to water for everyone in our region.

We all need to be part of the solution.

The challenge ahead

The International Panel for Climate Change projects that the East Coast of the North Island will be drier. Stronger westerly winds will dry our region in winter and spring. While we are likely to have more rain in increasingly volatile summers, there will be less rain overall. Droughts will be more common.

With support from Central Government, Hawke’s Bay Regional Council has completed New Zealand’s first region-wide water assessment. It lays out how much water we currently have, how it is used, and how much we might need in future.

The Regional Water Assessment (RWA) confirms that many of our waterways are at or near capacity. The gap between what our waterways can give and what we need to sustain our environment will continue to grow with climate change.

Across the 2019/2020 year studied, we took 138 million cubic metres of water from our rivers, lakes and aquifers; 64 per cent was used by agriculture, 19 per cent by our towns and cities, and 13 per cent by industry.

If we make no water-use reductions at all, we could have a shortfall of nearly 115 million cubic metres of water by 2060.

The needs of the environment will increase under climate change, and ensuring its protection is our number one priority. So, that unmet demand represents pressure on our communities and our economy. Economic analysis shows diminishing water security could see our GDP drop by up to $110 million per annum by 2060. That’s a lot of jobs.

We have choices

It’s a grim picture but, thankfully, there is good news.

A massive 16 billion cubic metres of rain fell in our region in the year studied. We have enough water – just not when we need it most. If we make significant improvements, we could reduce the shortfall to 33 million cubic metres by 2060.

But, we need to pull every lever we can to reduce the amount of water we use and hold water in the environment for longer. The RWA identifies practical options for this.

To reduce demand, we need to be more efficient with irrigation and processing, we need to improve our farming practices to retain soil moisture, and towns and cities need to conserve water.

To understand how much we need to reduce our water use, we need to understand how we might increase supply. If any supply options were possible, the priority would be to supplement the aquatic ecosystems of our rivers and lowland streams, building greater reliability and resilience to climate change.

Through the Regional Water Security Programme (RWSP), we are investigating the viability of underground water storage for Central Hawke’s Bay through a proposed Managed Aquifer Recharge pilot, and options for a small-to-medium-sized community-owned water storage facility for Heretaunga.

If ruled out, then the community will understand how big the collective effort will need to be to reduce our demand.

Even with these efforts, we will still have less water, but we will be a lot closer to ensuring Hawke’s Bay has long-term, climate-resilient, and secure supplies of freshwater, for all.

A new direction

Central Government is driving a step-change in freshwater management, setting its direction through Te Mana o te Wai and the National Policy Statement for Freshwater Management. They put the health of the wai first, then the community – and only after that can other uses be considered. Te Mana o te Wai also puts the community and tangata whenua at the forefront of the korero.

The regional council is considering these through the Kotahi Plan, which it is talking to the community about over the next few years. As Treaty partners, iwi and hapū have a significant voice in the direction we take in freshwater management within the Kotahi Plan.

The RWA informs that conversation and provides some options but it’s up to the community to decide what sort of future it wants. It is vital that we work together as a community to solve these complex issues for every generation.

• Hinewai Ormsby is chair of Hawke’s Bay Regional Council.