This article was first published on RNZ.
Te Arawa Lakes Trust says it has no “exclusive seat at the table” when it comes to Crown-led water management, as ongoing issues with the Ōhau Diversion wall raise concerns about the water quality of Lake Rotoiti.
The trust are owners of the lake bed under the Te Arawa Lakes Settlement Act, and are calling for greater recognition of its role as kaitiaki and a more meaningful seat at the decision-making table.
The Ōhau diversion wall stretches across 1.3 kilometres and was built in 2008 to improve the water quality of Lake Rotoiti by stopping nutrient-rich water flowing in from Lake Rotorua.
However, holes have appeared near the surface of the wall, raising concerns about increased algal blooms and water quality.
The $11 million structure was expected to last 50 years but showed signs of corrosion as early as 2014.
Chairman Wallace Haumaha said the ongoing issues with the Ōhau Channel diversion wall were “yet another symptom of a broken, Crown-led water management system that continues to ignore our role as kaitiaki”.
Earlier this year, the Bay of Plenty Regional Council said it would “accelerate” trials to address the problem. Haumaha welcomed this progress but said all voices, especially those of mana whenua, needed to be part of the decision-making process.
“As we work together to find solutions, it is vital that all voices, especially those of kaitiaki and local communities, are included in the decision making processes that impact our waterways and the wellbeing of our people,” he said.
Under the Te Arawa Lakes Settlement Act, the trust is responsible for the rights and obligations that come with lakebed ownership, including existing structures, commercial activities, and public utilities.
In June, over 60 Māori land trusts, representing more than 150,000 landowners, hapū and iwi, filed legal proceedings in the High Court against the Crown. They allege the government has repeatedly failed to uphold Māori rights and responsibilities over freshwater.
Te Arawa Lakes Trust is a part of this claim.
“This is about restoring balance and our ability to exercise proper kaitiakitanga. Māori have never relinquished our relationship with our ancestral waters,” Haumaha said.
“This collaborative approach is the driving force behind the coalition Wai Manawa Whenua, which brings together Māori landowners, hapū, iwi collectives, and national organisations such as the Federation of Māori Authorities (FOMA) who together have filed legal proceedings in the High Court to hold the Crown accountable to ensure that Māori rights and responsibilities over freshwater are upheld, fostering a responsible stewardship that benefits everyone,” Haumaha said.
In a statement to RNZ, Toi Moana Bay of Plenty Regional Council chief executive Fiona McTavish said the Ōhau diversion wall remained “structurally sound and is compliant with its resource consent,” though microbial corrosion has created holes in the top metre of the sheet piling.
“It continues to divert most of the flow from the Ōhau Channel (Lake Rotorua) to the Kaituna River, bypassing Lake Rotoiti.”
McTavish said the water quality of Lake Rotorua has “markedly improved” since the Ōhau wall was installed in 2008, due to alum dosing, catchment land use and land management change.
“This means that even without the corrosion, the wall would not be having the same water quality benefit as it did when it was installed.”
Last week, McTavish said the regional council adopted a strategy which uses a “dynamic adaptive pathway approach to decision making,” focussing on making decisions in a flexible way that adapts to changing circumstances, rather than relying on rigid, long-term plans.
“This enables regional council to make the best informed and most timely decisions about the ongoing investment in the wall, ensuring those decision are good environmental decisions that will deliver water quality benefits, but are also financially practical.
“Under this strategy, decisions about the future of the wall are timed to consider updated science and engineering advice, community voices and alignment with central government expectations.”
She said making good environmental, but also financially sensible decisions was critical.
“We want to ensure that any investment delivers the outcome the community desires, is based on the best information and is not unnecessarily rushed.”
McTavish said Ngāti Pikiao Environmental Society, representing mana whenua Ngāti Pikiao and Te Takinga, had been briefed and “continue to support the wall so long as it is providing benefit to lake water quality.”
“Regional council staff will continue to work with Ngāti Pikiao Environmental Society on the decision making in respect of the wall and ensure that decisions made about the wall are informed by the best available science regarding water quality.”
The working relationship between Te Arawa Lakes Trust and regional council governance, leadership and staff continues to be productive and positive, McTavish said.
“Regional council staff have briefed Te Arawa Lakes Trust kaimahi regarding the wall and sought their guidance on how Te Arawa Lakes Trust would like to provide advice regarding the issue.
“TALT staff have advised they will brief their Komiti Taiao as a first step, we have offered support for this briefing and await further direction from Te Arawa Lakes Trust kaimahi.”
By Layla Bailey-McDowell and Te Manu Korihi of RNZ.