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Saving Lake Tūtira

Bridget Freeman-Rock01 October 2017

As freshwater scientist Andy Hicks says: “Tūtira could be a huge asset for the region, it could be our Lake Taupo, but at the moment it’s a huge embarrassment.”

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Lake Tūtira was once famous for its eels, freshwater mussels and ax. Highly treasured by the Tangata Whenua, Ngti Kurimhiki, the lake offered both physical and spiritual sustenance to hap in their seasonal alternation between Tangoio and the Maungahururu ranges. For more recent generations of Kiwis it’s been a beloved recreational site for trout shing, kayaking and other outdoor pursuits, with popular DOC reserves, Shine’s Falls, Boundary Stream and Whitepine Bush, nearby.

Now, however, the lake stinks, the eels and trout are dying, children can’t go near it, and with State Highway 2 wending directly beside the visibly sick waterbody, it’s a contradiction to NZ’s clean green image that tourists can’t ‘unsee’. Local kids are reportedly ashamed to say they come from Tūtira due to the lake’s notoriety. The last two summers have seen the lake blighted by a sludgy mass of cyanobacteria, and while Tūtira has faced signifi cant water quality issues over the last 30 years, it’s now in an untenable state of ill-health.

Blue McMillan, local farmer and caretaker of Tūtira Regional Park, has lost dogs to the toxic algal blooms (the worst he’s ever seen), and he himself gets headaches and stinging eyes from the ammonia coming off it: “You have to plan your days” according to the way the wind blows. Blue also manages the DOC camping grounds, but these days there’s little camping, and with the lake’s demise, the farmstay cottage he set up has been seriously impacted.

It’s obvious to everyone that something must be done.

The Hawke’s Bay Regional Council has designated Tūtira one of its environmental ‘hotspots’ to benefit from a dedicated Kickstart Fund for immediate action. And in April HBRC – together with hapū representatives, Maungahururu-Tangitū Trust (MTT, who were handed back most of the lake bed and a decision-making role as part of their 2013 Treaty settlement), and with strong community backing – applied to the government’s Freshwater Improvement Fund (FIF) for significant funding ($1.5 million) towards a comprehensive four-year lake restoration plan, which is all but formally secured.

 

Tutira Restoration Plan:Total $3.6m over 5 years / HBRC $1.6m

MTT are 12 months into their own hapū-led project, Tūtira Mai Ngā Iwi, which involves extensive education and consultation, with a riparian planting, fencing and native regeneration schedule now underway.

So, what does this mean in on-the ground terms, and what will it take to restore the mauri, or life force, of Lake Tūtira?

Sediment and phosphorous
Formed by a slip some 6,500 years ago, Lake Tūtira (along with sister lakes Waikōpiro and Orakai) is surrounded by steep hill country in a dynamic geological landscape with highly erodible soft soils. “It’s an excellent sediment trap,” explains HBRC’s Hicks, “in a catchment with a lot of erosion.” Centuries of sediment in fact, have settled on the bottom of Lake Tūtira, an occurrence exacerbated by the extensive conversion of bushland into pasture 150 years ago.

It’s a deep lake (42 metres) with little inflow from streams, meaning a long turnover time for water (5-8 years). The inlet and outlet are on the same side which limits lake flushing, and with long, hot summers, stratified layers (warm top, cold bottom) create ideal growing conditions for algae in the surface waters.

While stratification is not itself a problem, when combined with excess nutrients (‘eutrophication’, and the organic material that’s generated) it can be. The main culprit is phosphorous. Eutrophication starves the water of oxygen, impacting aquatic life and perpetuating the cycle (without oxygen in the bottom waters, phosphorus, for example, can’t bind to sediment and instead remains constantly, cumulatively available within the water column).

Tūtira is especially prone to summer storms, which bring a “fresh pulse of nutrients at a time when conditions are perfect for algae,” such as New Year’s 2016.

Since then there’s been “more or less a constant algal bloom,” says Hicks, with the lake recently changing from a ‘eutrophic’ to ‘supertrophic’ rating, which means it now has ‘extreme’ rather than ‘high’ levels of nutrients and algae.

Coinciding with this, there have also been three separate “fish kills”: large eels and large trout died in early January 2016; small trout died in late January; and a further fish kill in December 2016 only seemed to affect eels. So far explanations are speculative as to why different groups of fish are being so drastically affected; while it appears related to the algal blooms, there’s clearly a culmination of factors.“

Tūtira is a microcosm for Hawke’s Bay and a perfect canary,” says Hicks. “It’s a sensitive receiving environment.” And what happens here and how we work to turn it around has a much wider implication for the region than “fixing” a lake. Its fate is intricately entwined with our relationship to land and water.

Diversion of Papakiri Stream
The introduction of top dressing (i.e. super phosphates) in the 1950s was a turning point for the lake. Paul Harris, Tūtira farmer and former Nuffi eld scholar, points out that much of Tūtira was leasehold land for years, and so many of the farms in the catchment were developed first in the 1960s and 1970s when fertiliser was cheap.

There was a particularly bad algal bloom in 1976. By the 1980s, the Papakiri Stream (also known as Sandy Creek) catchment to the north of the lake, where the most intensive land-use is, had already been identified as a major source of nutrient.

According to HBRC chairman Rex Graham, an initial report in 1981 recommended that 95% of the catchment be retired, but this was “put in the bottom drawer” because it was too hard (since then 40% of the catchment has become dairying). Instead, in 1982 the stream itself was diverted, bypassing the lake, and the large wetlands it flowed through (“the liver or lungs of the lake”) drained. But in flood events the stream still breaches its banks (most devastatingly with Cyclone Bola in 1988) and the back flow flushes in – a quarter of the current phosphorous input is estimated to come from this pathway.

The decision to divert the stream, made without due consultation, caused a lot of ill-sentiment, particularly among Māori landowners at the northern end where the wetlands once were. Cutting the ‘umbilical cord’ to the lake, which significantly impacted eel populations, remains a wound in the community, and the current regional council has had to work hard to rebuild relationships.

“It’s a key part of what needs to be done,” says HBRC councillor Paul Bailey. “But we’ve got an opportunity right now, where everyone wants to do something: there’s a real community will for action, the staff in council are the right ones to lead the charge, and there’s political will around the council table itself.”

Andy Hicks

Tutira is especially prone to summer storms, which bring a “fresh pulse of nutrients at a time when conditions are perfect for algae,” such as New Year’s 2016. ANDY HICKS, HBRC FRESHWATER SCIENTIST

Action plan
Bailey, who holds the council portfolio for Tūtira, outlines the council’s tabled actions for Lake Tūtira – “the list of things staff presented us with as needing urgent attention,” which HBRC agreed to progress irrespective of the government funding outcome.

 

 

Cr. Paul Bailey

“They’ve taken the low-hanging fruit, but we’ve got to go up the ladder now, we’ve got to do the difficult stuff .” PAUL BAILEY, HBRC COUNCILLOR

There is a strong community desire to reconnect the Papakiri Stream back into the lake; indeed it was a core commitment sought by Maungahururu-Tangitū Trust. Many believe there’s no choice; with the age of Tūtira’s water, and young water flowing past, we’ve got to redirect it back into the lake.

Because of the current nutrient risk from the catchment, HBRC is looking at a controlled release rather than a full-scale re-opening. The most neutral risk is to allow low-flows back into the lake and to stop floods from entering, building to a 70% stream in-flow or higher as the catchment improves.

HBRC is working with Māori groups regarding the potential reversion of farmland to wetland at the northern end. The restored wetland would help filter sediment, among other benefits – though it may impact the trout hatchery, but that’s another story. Considerations are also being made for opening a channel, potentially for eel spawning, into Lake Orakai, which would also improve water quality.

For a short-term band-aid fix, HBRC intends to pilot an artificial aeration system in Lake Waikōpiro this spring, which if successful will be trialled in Lake Tūtira over 2-3 years. Bailey likens the aerator to a pace-maker, which will keep the lake ticking while it’s not well.

Basically, it’s a “big version of a bubbler in a fish tank”, comprising a 100 metre or so long tube and an air compressor on shore, forming a big “bubble curtain”, which creates a water current. The bubbles act like a conveyor belt of water, mixing those cold and warm layers, allowing suspended sediment and nutrient to filter down. This has worked successfully in reservoirs of comparable size east of Auckland and in Lake Manuwai, Kerikeri. Although an earlier version of bubbling technology was tried unsuccessfully on Lake Tūtira in the 1970s, modelling of a modern oxygenation system indicates the bubbling would work now.

Any mitigation option for the lake itself, however, needs to be agreed to by MTT, who are still carefully weighing the solutions through their hapū wananga. The use of chemicals is the only solution to be firmly ruled out.

Bailey believes HBRC’s purchase, and replanting, of the eastside block of the lake in 1998, now Tūtira Regional Park and site of the council’s mānuka plantation trials, shows there was some foresight from the council of the time. “They’ve taken the low-hanging fruit, but we’ve got to go up the ladder now, we’ve got to do the difficult stuff .”

And that means managing the catchment – the fundamental issue – by improving on-farm practices. “It’s the same story as everywhere else”; it’s about water quality (nutrient and sediment); riparian planting; retiring steeper blocks; restoring wetlands further up the catchment. “There are so many variables, we don’t know what it will take to make effective changes, but any solutions will have to be tailored to the idiosyncrasies of the land.”

An integral objective of the $3.5 million Te Waiū o Tūtira – Milk of Tūtira project is to develop an Integrated Catchment Management Plan, and to develop and implement farm environmental management plans throughout the catchment.

Hapu leadership
MTT’s general manager, Shayne Walker, says after 150 years of alienation from their land and resource, hapū are now able to enact their rangatiratanga, their kaitiakitanga again. “In our belief, we are of the land, of Papatuānuku, therefore, it’s not that we are caring for the land so much as caring for ourselves. We have an obligation, first and foremost, to our ancestors, and a responsibility to future generations, and we take this really seriously: the land is part of our whakapapa.”

“We will do the best we can to improve the mauri [life essence] of the lake, and when we talk about enhancing the mauri, that means everything: the birds, the community, the land around…. Part of the challenge with Lake Tūtira, was in the past HBRC, and to a degree DOC, took it upon themselves to resolve the issues, create the solutions without necessarily engaging with that wider holistic perspective.”

It’s therefore vital, from his perspective, that MTT are partners in any decision-making and that all stakeholders are engaged in the process. “We all have to take some responsibility in how we’re going to change it. We are all going to have make some changes in land use to restore the lake to what it needs to be.”

“We’re there to provide a long view on how we can resolve the issues and enhance the mauri of the lake. We’re not going anywhere. We’re thinking 50, 100 years into the future, and we’d love to be able to pass the lake onto the next generation in a better condition than what we’ve received it back from the Crown.”

… in 1982 the stream itself was diverted, bypassing the lake, and the large wetlands it owed through (“the liver or lungs of the lake”) drained.

In June MTT facilitated a community meeting for all to share (and hear) the concerns and wishes for the lake. Consensus seems to be that it was full, dynamic, “fresh”, giving a clear signal that the community sees the lake as Tūtira’s identity and wants the day-to-day issues they face as a result of its current state addressed.

Land-use changes
Tūtira has its fair share of dairying in the catchment – indeed, Tūtira was the original town milk supply for Hawke’s Bay until HB Milk Coop was absorbed by Fonterra. But all are owner-operated farms and actively engaged in a monthly, on-farm discussion group for improving practice.

Shayne Walker

“In our belief, we are of the land, of Papatuanuku, therefore, it’s not that we are caring for the land so much as caring for ourselves. We have an obligation, first and foremost, to our ancestors, and a responsibility to future generations, and we take this really seriously: the land is part of our whakapapa.” SHAYNE WALKER, GENERAL MANAGER, MAUNGAHURURUTANGITŪ TRUST

Paul Harris runs an integrated operation: both dairy and sheep & beef. Mixed farming allows him to spread the nutrient load – literally, “effluent is one of the most underrated things” – and to run a lower stocking rate: one cow to the hectare, in contrast to the 2-3 norm in Tūtira and Canterbury’s five to the hectare.

He says farmers in the Tūtira catchment will need to change techniques to suit the soil, and that more education is needed around different stocking rates, pasture grazing, the use of alternative forages, such as plantain, etc. There will be nitrogen caps.

Harris forecasts “quite a lot of changes”, but says farmers are “solutions driven” and in Tūtira they want to see the lake cleaned up. “We’re a community of productive people, we’re people that do things each day, we understand better than most what it takes, and we want it solved.”

Harris sees change as an opportunity, and says there’s a big space for artisan producers; if the lake is restored to health, producers can have pride in their product and market it with the Tūtira story.

Trees
When Blue McMillan’s family arrived in Tūtira in 1962, the land all around the lake was used for pastoral grazing with little tree cover.

Over the last 30 years he’s been involved in a lot of the tree-planting efforts on the eastside of the lake (in the days when tree-planting was subsidised), and left large portions of his own land to slowly revert back to native bush. He says that farming on steep land is not viable and environmentally irresponsible, though there’s little economic incentive these days to plant trees: “I probably wouldn’t get the rights to clear the kānuka now, even if I wanted to. But I do hope I get a rates rebate [for the bush regeneration]…. Carbon credits are a maybe in the future, we’ll see.”

Harris believes a “subsidised planting period is going to have to be reignited” on sheep & beef farms like McMillan’s.

One of the next steps to be taken is a multi-criteria analysis around forestry, and land utilisation post-harvest. While the jury’s out on forestry – good or bad? – in modelling HBRC has done, says Andy Hicks, it’s the best land-use for water quality, as forestry leaches the least nutrient and has the lowest sediment loss long-term.

The swath of pines HBRC planted out in 1992 as a means of soil control are due to come out, and to ensure there’s not a pouring out of sediment in the process, there will need to be mitigation measures employed, such as grassing the area straight after and the use of sediment traps. Engagement will be needed on whether to replant the land as forestry plantation or to retire it in natives.

McMillan says, “The community would like to see more natives instead of pines and a future regional park.” While he’s philosophical about it – “there are lots of natives coming up in the pines, anyway” – he sees a great future for HBRC’s Tūtira Park if it is restored back to natives. With Bell Forest one side and White Pine Bush on the other, “what a great opportunity to put something back in the middle with a beautiful lake!”

Visions for Tūtira
Many have been waiting for a long time to see effective action taken on Lake Tūtira, and everyone I spoke to expressed a quiet optimism that change is in the cards.

Guthrie-Smith Trust run an education centre and arboretum on the remaining 90-hectare block of the original sheep station, ‘Tutira’, and site of NZ’s earliest conservation efforts. Their vision is to develop ‘Tutira’ as a national centre for biological studies and biodiversity, and they would also like to be able to promote it as a “regional tourism hub” for outdoor recreational activities. They are very interested, and active, in seeing Te Waiū o Tūtira – The Milk of Tūtira project fulfill its aims, not least because it’s part of their core business, but because they see Tūtira’s potential to showcase both the legacy of human activity within the environment and pathways forward.

Chris Ryan has been involved with developing the trust’s extensive arboretum since 2002, building up their native and exotic collections, trialling trees for erosion control, timber, alternate crops, and bee fodder. “With the regional council, local iwi, and interested parties now on board,” he says, “we see the potential to become leading educators of sustainable, resilient land management.”

For Maungaharuru-Tangitū Trust, a restored Lake Tūtira will bring cultural tourism and economic opportunities. Already the hapū take a number of schools up to Tūtira to their wahi taonga (special places), such as the caves. In August they held their first community tree planting day down by the lake, with a good turn-out, from kaumātua to mokopuna, “They’re excited,” says Shayne Walker, “they’ll see those changes happening.”

For Blue McMillan, there’s relief: “Finally, some positives!” With funding in the pipeline, the hard work being done by HBRC on the ground, and MTT’s involvement, which has brought exposure to the issues, “It’s all coming to a head, which is a great feeling. Finally, it’s coming together.”

 

Bridget Freeman-Rock01 October 2017

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