Restoration men: Working on a plan to improve Lake Hayes' water quality are, from left, Mike Rewi, Jana Davis, Mike Hanff and Glenn Davis


A local iwi charity’s been given $1 million by philanthropist Rod Drury to get started on a long-planned project to clean up Queenstown’s Lake Hayes.

Mana Tahuna chief executive Mike Rewi says the money’s paying for the new charitable trust’s team to work through the resource consent process, apply for more funding, consult with private landowners, and soon get a team of workers on the ground doing preparatory work like fencing, pest control and willow tree removal.

‘‘It’ll see us through a good year’s worth of work.’’

The project, which is estimated to cost $10m and take four to five years to complete, will follow a blueprint by Arrowtown environmental science consultancy e3Scientific.

The company, led by Glenn Davis, has just completed a $50,000 ‘Lake Hayes vision study’ commissioned by the Friends of Lake Hayes.

It involves creating a 2.8-hectare wetland at the lake’s northern end, installing sediment traps at intervals along the lake’s tributary, Mill Creek, and riparian planting.

The study estimates the project will reduce the amount of sediment and nutrients entering the lake by 25%.

The presence of phosphorus from the historical use of fertilisers in the lake’s catchment has caused frequent, toxic algal blooms that make it unsafe for recreational use by people and dogs.

The trust’s chief operating officer, Jana Davis, says the goal is to make the lake swimmable again.

‘‘For us it’s about providing work for our community, improving water quality and fulfilling our role as kaitiaki of our takiwa (area), just as our tupuna did before us.’’

Rewi says the trust’s working on fully-funding the project, with applications in or pending to the Department of Conservation’s ‘Kaimahi for Nature’ fund and the Ministry for the Environment’s freshwater improvement fund.

Both are a subset of the government’s $1.1 billion Jobs for Nature fund announced in May’s Budget.

Although the trust’s stated objective is to look after Queenstown’s Maori and Pasifika residents affected by the fallout from Covid-19, ‘‘we know the whole community’s in need’’, Rewi says.

‘‘We’re the leaders of this project, but we are and have already in our previous work employed foreigners and other members of the community that’ve been affected by Covid.’’

The trust’s first contract after it was established in June was employing 14 people to plant nearly 8000 mountain beech trees this past autumn on Mt Dewar Station.

Drury, a part-time resort resident who since 2015 has been lucratively selling down his stake in Xero, the cloud software firm he co-founded 14 years ago, tells Mountain Scene he was attracted by the ‘‘scientific, data-driven approach’’ being taken to the project.

It’s an opportunity to test an integrated approach to restoring a waterway in a highly-visible location while ‘‘measuring, learning and educating throughout the journey’’, he says.

‘‘If we can make a positive, measurable difference, we hope these remediation methodologies will be deployed throughout New Zealand.’’

Friends of Lake Hayes boss Mike Hanff says the project’s evolved from more than 50 years of scientific research into the lake and how it can be remediated.

The group’s members are excited Mana Tahuna’s driving the project, and ‘‘playing a huge role in turning around the current degradation of Lake Hayes’’.