Northland’s bold initiative to revive a treasured taonga has received international recognition for its Indigenous-led, science-backed approach to restoring water quality and biodiversity.
An ambitious plan to reverse the decline of the largest lake in Northland is set to gain global attention at an upcoming international gathering of lake management experts in Australia. The restoration plan for Lake Ōmāpere, a polluted lake prone to toxic algal blooms located near Kaikohe, was presented to industry leaders, decision-makers, practitioners and researchers at the World Lake Conference in Brisbane, Australia, in July 2025.
Representatives of the Lake Ōmāpere Trust were invited to the sustainable lake event to outline their comprehensive plan, which aims to revive the mauri of the lake by improving water quality, restoring indigenous biodiversity, and ensuring a sustainable resource to support the wellbeing of the community as it once did more than 50 years ago.
The 12.3-square-kilometre Lake Ōmāpere is around 2.6 metres deep, but, during summer, it drops to as low as 1.5 metres. Two centuries ago, the lake, which sits in a volcanic area, was much deeper and was regarded as a food basket (pātaka kai) of Ngāpuhi; however, since the 1800s, the felling of surrounding forest has allowed sediment to wash into the lake and reduce its depth.
The Ngā Kaitiaki o Te Roto Ōmāpere restoration plan, created with the guidance of whānau, hapū, iwi and community, has been supported by freshwater, ecological and agricultural science experts, including the National Institute of Water and Atmospheric Research Institute (NIWA), Department of Conservation (DOC), 2022 Kiwibank New Zealand Senior of the Year Rereata Mākiha, and internationally-acclaimed lake restoration expert Professor David Hamilton.
The plan addresses water resilience and water quality issues, which became evident in the 2020 drought when attempts by the Far North District Council to access the lake as an emergency water source for Kaikohe failed due to concerns over water quality. Far North District Council Mayor Moko Tepania is excited about the restoration plan.
‘I congratulate the Lake Ōmāpere Trust on the significant mahi to incorporate multiple outcomes, including green infrastructure, flood resilience and water resilience into the restoration project,’ he says.
The scientific basis for the restoration plan has been supported by NIWA. Last year, the Crown Research Institute completed a review of more than four decades of research conducted on Lake Ōmāpere, which included the 2021 feasibility to raise the lake level by 2.5 metres for the purpose of water storage; however, it failed to demonstrate that water quality would, in fact, improve for the purpose of community use. Building relationships and working together is vital to the success of the plan, says NIWA Chief Scientist Dr Erica Williams.
‘Our long-term relationship with the Trust is important, and as partners we can support the environmental and water quality outcomes of the restoration plan, as well as efforts to restore indigenous biodiversity, working alongside DOC to bring back species such as the endangered quillwort plant, Isoëtes kirkii.’
Selection for the World Lake Conference recognises the inclusive, collaborative nature of the Trust’s plan, says Trustee Ani Martin. ‘What is most important is the relationships that have been built throughout Northland and across New Zealand to support the restoration of our treasured taonga. The plan reflects the deep relationships we’ve built.’
The plan addresses current and pressing issues for the region, including climate resilience and biosecurity, with the conference presentation another positive in the relationship between the regional council and the Trust, which was formalised in 2023, says Northland Regional Council Chair Geoff Crawford. ‘It puts Northland on the world stage regarding water quality and biodiversity efforts.’
Professor Hamilton says that hearing about the Lake Ōmāpere restoration plan at the World Lake Conference is critical for international practitioners. For too long, and even now in many parts of the world, the philosophy has been ‘we are the scientists … we know what is best for you’.
This approach fails to recognise and engage with community, iwi and policymakers, particularly Indigenous knowledge holders. Hearing about the Lake Ōmāpere restoration plan provides the global audience with an opportunity to understand a different, Global South perspective.
Northland MP Grant McCallum believes the invitation to present the plan to an international audience was a huge win for the Trust and the region. ‘Generations of Northlanders have both cherished and fought for the wellbeing of this lake. The recognition of Lake Ōmāpere on a global scientific stage gives me confidence that the Lake Ōmāpere Trust is on track with its planning, and that Northland may very well enjoy this beloved lake again in my lifetime.’
Te Rūnanga-ā-iwi-o-Ngāpuhii Chairperson Mane Tahere is thrilled about the achievement, which puts Ngāpuhi on the world stage. ‘Most importantly, we are excited about what this means for whānau and hapū, seeing our own people achieving, and demonstrating that, we as Ngāpuhi, can be world leaders.’
Acknowledging the many generations of whanau caring for the lake, Lake Ōmāpere Trust chairperson Tamaiti Wihongi says it is both humbling and exciting for the lake’s history and restoration plan to be heard at the World Lake Conference. ‘Perhaps now, finally, the voices of our tūpuna are being heard.’
Background
The first algal bloom was publicly announced in 1984 when children swimming in the Utakura River downstream developed sore eyes and diarrhoea, and consumers reported stomach upsets. Fish and mussels in the Hokianga Harbour turned bad not long after being gathered, and stock would not drink water from the lake or downstream. Algal blooms have continued up until the present day.
Ministry for the Environment’s ‘Our Freshwater 2023’ report stated that 46 per cent of lakes in New Zealand larger than one hectare had poor or very poor water quality based on trophic level index, which assesses the amount of nutrients, sediments and algae in water.