But the Karamū is arguably our most significant awa, supporting much of Heretaunga’s productive lowland and urban environment – a catchment that encompasses an intricate network of small tributaries, spring-fed streams and creeks, channels and drains that feed into the main Karamū stem, flowing 40 kilometres from Lake Poukawa to Waitangi Estuary.

On its path to sea through farmlands, orchards and lifestyle blocks, the Karamū navigates a matrix of problems: heat exposure, nutrient runoff, soil erosion; and the whole set of urban stormwater issues, along with industrial contributions, commercial impacts and historical contaminants that feed into the system. By Ruahapia, just north of Hastings, the Karamū is in an extreme poor state of health. 

Basically, everything that happens in this catchment has an impact. And there’s no one area of blame – it’s a complex ecology, with a complex set of demands upon it, and a legacy of what, with hindsight, we could term ‘wrong choices’. 

In many ways, the Karamū embodies the gamut of water issues faced in Hawke’s Bay, while also presenting a unique case for an integrated catchment approach that cuts across all land-use, both urban and rural. 

The journey 

The Karamū begins in Lake Poukawa – part of an ancient peat swamp, believed to be one of the oldest in New Zealand, that encompassed much of the lowland area from Pekapeka wetlands right up to Te Aute Trust Road. It was an important hunting and fishing ground for tangata whenua, navigable by waka from Pakipaki. 

In fact, to look at images from the 1800s is to see that Hawke’s Bay was once an extraordinarily watery place, with its braided, meandering rivers, lakes, lagoons. Over the last 150 years, we have lost 98% of our wetlands due to water drainage, land reclamation, the safeguarding of flood-prone areas.

In the ‘80s, Pekapeka Wetlands was a pig farm. Today it’s a showcase of environmental restoration, with flourishing wildlife, including endangered species like bitten, and plays an important role in filtering nutrients within the agricultural landscape.

Aki remembers the abundance of flounder and longfin tuna in the river as a child, and of swimming all the way down from the Chesterhope Bridge. Nowadays, due to cumulative influences from upstream, the river that flows past Kohupatiki is unswimmable; the fish inedible.

From Pekapeka, the Karamū travels as the Poukawa Stream to Pakipaki, ‘gateway to the Heretaunga’ – site of three marae, a natural spring and rich cultural history. There it meets up with a confluence of the Upper Awanui, Paritua and Karewarewa streams. 

From Pakipaki, it becomes the Awanui Stream, which merges at Pukahu with the Irongate that run south from Flaxmere to Longlands. From here it’s known as the Karamū, collecting the Louisa and streams that run down from the Havelock hills, like the Mangarau and Karituwhenua, as it makes its way through Brookvale and Mangateretere to Ruahapia, north of Hastings. From Ruahapia it wends through Whakatu, and at Pakowhai takes in the Raupare, following the old Ngararuroro gravel bed as the Clive River (or Ngaruroro-waimate) out to the coast. 

Aki Paipper, of Kohupātiki Marae, across the river from the original Tanenuiarangi pa behind Whakatu – one of the oldest continuously occupied Māori habitations in Hawke’s Bay – relates how the Ngaruroro-waimate was a trading route pre-Captain Cook: “This is how we connect to all marae [up the catchment]. From the whalers and sealers, our people would collect seeds, potatoes and things, and take them up to Poukawa area because it’s fertile there. They grew it all and then took it out back to sea to trade with the whalers and sealers – we had an economic base that was unbelievable.”

Aki remembers the abundance of flounder and longfin tuna in the river as a child, and of swimming all the way down from the Chesterhope Bridge. Nowadays, due to cumulative influences from upstream, the river that flows past Kohupātiki is unswimmable; the fish inedible.

“The silver bullet for the Karamū is planting river margins, which gives the whole cascade of benefits…”

Valuing our lowland streams

HBRC freshwater scientist Sandy Haidekker says, when people think of a healthy stream, most think of a high-country stream: crystal clear, fast flows, big boulders, etc. Whereas lowland streams, like the Karamū, are less dynamic with slowly flowing water, naturally occurring tannins and soft sediments rather than gravel, and may look ‘neglected’. They tend to be less appreciated, their biodiversity less understood. 

Typically, you don’t get any algae in lowland streams, so guidelines for algal growth don’t apply, and soil erosion is less of an issue due to the flat gradient. Instead, you’re managing for macrophytes (aquatic plants, with roots, stems, leaves). In a balanced state, macrophytes provide habitat for aquatic species, but if they grow too much they choke the stream, trap sediment, and rob the water of oxygen at night. Riparian vegetation, low-hanging branches and plant debris, also offers habitat, as well as shade, but in Hawke’s Bay we’ve lost virtually all the indigenous cover that once protected our lowland waterways.

Biodiversity as measure

Macroinvertebrate communities are an indicator for water quality – like the canary in the mine. You look at the whole set (the MCI), explains Sandy, and if you’re only left with the worms and snails (“which have these incredible adaptation mechanisms for atrocious conditions”), then you know something is wrong. Parts of the Karamū are down to worms and snails at best. 

Native migratory species, like white bait (which are actually five different species, with inanga, which is in national decline, being the most common in a whitebait catch) and pātiki, need connectivity to the sea as well as a quality freshwater environment, and they’re the ones we should be protecting, says Sandy. But also smelt, and mullet and many other fish, that thrive in slow moving water and the proximity to the coast. 

The fact that we have these macroinvertebrate and fish species in the lower Karamū, some of which are endemic to New Zealand, makes makes caring for the waterway a much larger responsibility. As Sandy points out, “It’s quite a heritage we have here and we are the only ones that can safeguard it, so that makes the Karamū special in a global sense.”

While we can’t go back to a pristine, natural state, the challenge becomes, how can we maintain healthy functions in a productive environment, restoring the awa’s mauri and supporting a rich diversity of species? 

At Crosses Road, I go down with Sandy to the water beside handsome clusters of harakeke, and behind the wide grassed berms, stands of established vegetation (both native and exotic) planted in various stages of enhancement over the last 80 years. On the far bank: pūkeko, paradise ducks, a cheeky rabbit. We take a sample from the stream, that’s running swift and milky after the recent big rains. We find it swarming with exotic fish. Improving the Karamu would mean tipping the balance towards more of our typical lowland species. 

“There’s so much potential,” says Sandy. “If we can bring it back to a healthy state, we’ve got something really quite special and rare.”

High temperatures, low oxygen

To better understand why the Karamū is struggling, Sandy studied all the different aquatic species at several sites, and their patterns of population increase and decrease in parallel with a whole raft of environmental parametres. Her results clearly show that the most limiting factors for aquatic life are high water temperatures and low oxygen (in some cases, zero), as well as lack of habitat. 

The Awanui Stream, for example, which passes through sheep and beef farmland, has no shading at all and is heavily impacted. It’s very hot (reaching 26C easily in summer, which is “way too hot for aquatic animals”) and “choked with an unbelievable amount of macrophytes”, in addition to high nutrient levels due to “leaky” soils. IIn contrast, the streams that pass through the vineyard areas, such as from Bridge Pa to Pakipaki such as the Raupare, are cooler, clearer, because they are spring-fed, and thus don’t suffer the same low flows and loss of oxygen. Orchard areas may have less nutrient runoff but they face the same issues as the Awanui due to lack of shading.

Sandy is adamant: “The silver bullet for the Karamū is planting river margins, which gives the whole cascade of benefits: it shades out the macrophytes (so you get to a better volume), which allows for better flow and more oxygen; it reduces the temperature (or keeps it stable); creates habitat; and gives connectivity to species that need land in their adult stage as well as insect life.”

The regional council has run successful planting and shading trials, which support the effectiveness of riparian planting. They are currently modelling how we can achieve 70% shade of the waterway, as this will reduce macrophyte abundance to good amounts, as well as a strategic planting approach to maximise efficiency and benefit. 

When it comes to moderating water temperature, which has a cumulative impact, we have to start higher up in the catchment, says Sandy. It’s important, and effective, to focus on the small streams first, as these are far easier to shade, with a faster result, and a tangible difference – “we’re talking several degrees Celsius”. 

Te Karamū Stream enhancement strategy

Steve Cave, manager of HBRC’s open spaces, says the council’s main priority for the Karamū catchment has been to retain flood control and drainage, but better balance needs to be found by “blending in ecological and cultural values”.

In order to re-establish an indigenous eco-system within this modified landscape, council is working “to create nodes of habitat along the awa corridor”. Planned in a nested forest patch configuration, this includes, ideally, core sanctuaries (6-7 ha every 5km); habitat nodes (1.5 ha every 1-2km); and small native groves as stepping stones. 

They’ve created a database for potential revegetation species that would have been found in the Hawke’s Bay landscape prior to human settlement. These include on the alluvial plains, podocarps (mataī, kahikatea, tōtara) and wetland species such as toetoe, flax and raupō.

While the traditional maintenance mechanism has been grazing, the council is “continually looking at ways to fully retire our margins from cattle grazing,” says Steve – though not all stock will be excluded at this stage. “Our goal is to fence it all.” One avenue for rethinking margins is increasing public recreational use in suitable ways.

“The outcomes from the cycle ways have been huge,” explains Steve. “We’re focusing on that pathway connect, providing appropriate ways for people to interact with the water and multi-use opportunities. “The more eyes on the stream, the more support to improve it. The more use, the more ownership.”

One idea Steve says they’re exploring is kayaking, with multiple entries and exits along the Karamū/Clive main stem, from Pukahu to Waitangi, for example, with a ramp and kayak hire at both ends, and at Crosses Road (Havelock North).

“Part of our long term vision is to look at creating longer pathways along the Karamū, for example, from Havelock North to Pekapeka.” There’s a real demand for such walking tracks, but it has to be approached “at an appropriate pace”, because landowners have to be on board.

An initiative that’s gaining momentum in this regard, is the ‘adjacent neighbours programme’, which encourages neighbours interested in what’s happening on private land to get involved in a chain effect – “they invest; we plant.” The aim is to accelerate overall re-vegetation.

“We need to take up every enthusiasm and momentum,” says Steve. “Our long-term success is dependent on community involvement.” 

Every year HBRC runs a winter planting programme, with 80% undertaken by volunteers, the rest (and the maintenance) by contractors. This year, 35,000 plants are due to go in the ground; from 26 May the council will be holding public planting days on consecutive weekends. Steve says the number of “planting groupies” is growing (the regulars who turn up at every opportunity), and community groups like Forest & Bird are making a big difference.

Community initiative

Forest & Bird (Havelock North-Hastings branch) have planted downstream from Pekapeka – two hectares in three stages, over three years. While the project, in the main, is completed, we’re there today with the Kiwi Conservation Club (KCC), filling the gaps with donated cabbage trees. 

You can see the range of growth and response to microclimate conditions, such as the way the line of established gum trees significantly improves the robustness and growth of new plantings, or where the limestone substrate makes for a poorer take. In the 4-5 years since planting began, the state highway is already buffered by thick foliage, wildlife is returning. Branch coordinator, Linda Johnson: “Trees are so beneficial, not just for our biodiversity, birdlife, but for our wellbeing. We all need some wildness in our lives.” 

Forest & Bird have monthly working days, year round (“hand-releasing” plants, watering, clearing ground) as well as planting days with the KCC (www.kcc.org.nz). 

Their new project site is along the Karamū at Pukahu, where the Awanui and Irongate streams converge. The aim is to create a core sanctuary, which in addition to riparian benefits, will form part of a native corridor from the Kaweka ranges to the coast. 

Operation Pātiki

From the Essex Crescent reserve at Whakatu across from Kohupātiki Marae, I walk along the limestone cycleway with Aki Paipper, one of the Karamū’s staunchest advocates. Water flow is virtually nil, cow cress proliferates, and the river bed is covered in gunk. But on a sunny day, with native trees and shrubs flourishing on either side, birds, it’s a beautiful, peaceful place to be. 

The marae was the first to move on planting up the stream banks in the Karemū catchment. In 2009, Operation Pātiki, with support from HBRC and DoC, began work on five hectares of indigenous landscaping. 

Riparian vegetation along the Kohupātiki-Whakatu stretch now includes kānuka and mānuka (for the bees), a grove of 200 tōtara (“for our future carvers”), 65 varieties of harakeke (for weaving), kōwhai for tui, along with some old crack willows that continue to provide habitat for ducks and shade in the interim while everything grows.

Done with planting up Kohupātiki, the marae continues planting “around the bend”, moving further along to connect up to the estuary. This is part of a bigger vision, which includes a plan for growing “soft tourism” – “we want to get waka back up the river again” – along with the restoring of customary rights (“to feed our people”) and collective wellbeing.

Aki is adamant, however, that practices that are influencing the Karamū so adversely in the first place must stop. “We need a new change in attitude towards the environment. And we need an integrated catchment.”

Ambitious plans

HBRC chairman, Rex Graham, has ambitious plans for the Karamū too: “Within a decade we’re going to have it all planted.” He concedes it’s going to take “serious resource and serious energy,” to move up into the catchment, but says, “We’re going to do it, come high or low water… Not everyone’s going to be happy about it because there is some sacrifice required, but we’re going to do it anyway.”

Along with planting trees, he sees wetlands as a prime way for managing our land-use. “Pekapeka Wetlands is a great example: it takes out 80% of the nitrates that come from Poukawa. We need to get wetlands back into the landscape… it’s such a good way to filter our commercial activity.”

Turning the state of the Karamū around is “definitely doable” in Rex Graham’s eyes. But “Regional council cannot do this alone, we need to encourage and embrace community groups to help us in this together. Forest & Bird and Kohupātiki Marae are two stunning examples – they’ve done such an outstanding job in the Karamū catchment.”

Determined to see follow through, he’s working to bring all 12 marae in the catchment together, along with interest groups and councils, to work out an immediate and long-term community action plan, with everyone taking ownership of “their stretch”.

Rex wants to encourage schools to adopt an area, like Clive School, which has taken initiative with the Waitangi Estuary, and with support from the Open Spaces team at HBRC has implemented an annual planting and education programme. 

He’d love to see a freshwater sanctuary for eels, and, ideally, to safeguard the catchment against commercial eeling, as eel populations are so depleted. Ultimately, he wants to see “water clear enough for the kids in Mangaroa [Bridge Pa], Pakipaki, Havelock North and Whakatu to swim in. Can the kids swim or not? – that should be the KPI.”

The test of Rex’s ambition will be the outcomes of TANK – with a resolution (following five years hard, collaborative work) due to go before the wider Hawke’s Bay community in July. Public consultation and submissions will be called for, with a comprehensive management strategy for the Heretaunga catchments ready for implementation (all going to plan) in 2019.

So, what is your commitment to the waters you live alongside, and how will you be ensuring that our collective legacy is not one of wrong choices but a proactive step-change for the future?

Love the Karamū: Get involved

> Plant Thru Winter 2018

Hawke’s Bay Regional Council runs a winter planting programme, with up to 10 major planting events planned this year. Community planting days are listed on the HBRC website under the ‘Join it’ tag. 

> Pukahu Project

Help with Forest & Bird’s creation of a 7ha native sanctuary along the banks of the Awanui and Irongate streams at their confluence in Pukahu: www.forestandbird.org.nz/branches/hastings-havelock-north

> Marae

Speak with your marae – many are actively working with HBRC and DOC on enhancement projects adjacent to marae or supporting enhancement work in other locations.

> TANK Plan

Have input into the TANK Plan for managing the Tutaekuri, Ahuriri, Ngaruroro and Karamū catchments, which will be up for public consultation and feedback in July/August: hbrc.govt.nz, under ‘Projects’. 

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