Water storage project proposed for Makaroro River in Central Hawke's Bay

The upper half of the Makaroro River has been identified as the only viable site for catchment-scale water storage as part of the Tukituki Water Security Project. Photo / NZME

A proposal for "catchment-scale" water storage on the Makaroro River in Central Hawke's Bay, at the same site as the failed Ruataniwha Dam, is the only similarity between the two projects, those leading it say.

New analysis commissioned by the Tukituki Water Security Project (TWSP) found that catchment-scale water storage on the Makaroro River was key to mitigating increased impacts from climate change and to achieving water security for Hawke's Bay.

A proposal to build the $330 million Ruataniwha dam on the same river was blocked by the Supreme Court in 2018, despite almost $20m of expenditure by Hawke's Bay Regional Council on consents and planning.

Mike Petersen, independent chairman of the TWSP, said expert advisory firm Lewis Tucker was engaged by the group to complete a scoping and validation of the business case for the project.

Mike Petersen, independent chairman of the recently-formed Tukituki Water Security Project, said the aim of the project was "environmental first and foremost". Photo / NZME

It found a mix of measures is required to address water security, but catchment-scale storage on the Makaroro River was a critical part of the solution to deliver water security for the region, and improve the health of the Tukituki catchment.

"It's exactly the same site but that is where the similarities start and end," Petersen said.

"The project itself is less about the site and the dam, as it is about the needs of the community."

He said 14 different alternatives had been analysed up and down the Tukituki catchment, but the current site on the upper Makaroro remained the only viable site.

It was entirely different from the Ruataniwha dam project in that it was a "purpose-driven rather than structurally driven project", with environmental needs prioritised.

Fourteen different alternatives had been analysed up and down the Tukituki catchment, but the current site on the upper Makaroro remained the only viable site. Photo / NZME

"The TWSP is an environmental initiative first and foremost, and a whole of Hawke's Bay project that is future focused, and with the aim of making Hawke's Bay the best place to live, work, thrive and play in New Zealand."

Petersen said the project highlighted that water security should be a key regional priority requiring a strategy that explicitly prioritises Te Mana o te Wai - ensuring the health and wellbeing of water is protected and human health needs are provided for, before enabling other uses of water.

"The Te Mana o te Wai hierarchy of uses is clear, and this creates a platform for a genuine and transformative plan that puts the health of the river and its people first."

Catchment-scale water storage as part of the Tukituki Water Security Project is only one of a range of measures required to address Hawke's Bay's water security woes. Photo / NZME

The first priority for water must be to Te Mana o te Wai and ensuring environmental and restoration needs were met, then fast-tracking adaptation to climate change, providing for community needs and human health and finally water for consumptive use.

Petersen said while there was "no silver bullet" for the region's water woes, adding it would take a range of measures.

The catchment-scale water storage project would complement other initiatives, including changes to farming practices and the recently announced Managed Aquifer Recharge Project initiated by the Hawke's Bay Regional Council.

"We know that without meaningful intervention, the outlook is bleak for the health of the catchment, and for the resilience and wellbeing of the communities it supports," he said.

"If we don't start capturing and storing water we are going to be severely constrained."

Mike Petersen, chair of the Tukituki Water Security Project, said without "meaningful intervention", the outlook is bleak for the health of the Tukituki catchment. Photo / NZME

He said the project would provide meaningful flows of water for restoration purposes into culturally significant water ways, provide a materially lower cost of water at a scale that ensures water security for the catchment in the long term, and improve access to reliable water for higher-value land uses.

The report provided a road map for the region to make "real progress" in addressing this issue and a "robust base" to work from, he said.

The group was now working to implement its recommendations, including working with local authorities and mana whenua to look at new ways to secure access to the 22ha of deemed conservation land that sits in the water storage footprint.

"We are also accelerating discussions with local, regional and national stakeholders seeking support for the project, and looking to secure funding to appoint a project implementation team.

"Finally, we are exploring options for user and public good funding of the environmental flows proposed for the Tukituki catchment."