About the Motueka catchment

Few valleys in Aotearoa summon the same awe as the Motueka. The folded ridgelines, mystical light and breath-taking scenery receive deserved accolades. Many people live beside, swim in, fish from, run and bike alongside, the beautiful Motueka awa, or its many tributaries. Iwi and hapū have a deep connection to the awa, and have historically used it for mahinga kai, rongoā, and other special places such as Te Puna o Riuwaka for healing and other practices. The catchment is home to many people, birds, insects, and plant species and residents of the Motueka Valley and its many tributaries are rightly proud of their awa.

Our whaitua (catchment)

A catchment, or whaitua, is an area of land where rain flows into a common river, lake or other body of water. The Motueka Catchment Collective have decided to use the boundaries of the Motueka Freshwater Management Unit to define our catchment. Figure 1 shows catchment boundaries and extent.

The catchment has an area of 2,200km2, and extends nearly to St Arnaud at its southernmost boundary, where the Motupiko River starts in Te Tiritiri o te Moana/Southern Alps, the Maungakura/Red Hills in the south-east where the main river, the Motueka begins, and up to Mt Owen and Tu Ao Wharepapa /Mt Arthur where the Wangapeka River begins its journey. It also includes the Riuwaka River catchment up to the top of Takaka Hill, along with all of the Motueka township and part of Lower Moutere encompassing the Motueka river mouth, estuary and delta.

This link gives a more interactive / zoomable map of the catchment – Click here

The catchment environment is full of beauty, bounty and taonga. This includes part of the treasured Kahurangi National Park, with its gnarled beech trees, popular walking tracks, rising population of whio and many other native birds, and alpine tussock and sometimes snowy peaks of Tu Ao Wharepapa, picturesque and quiet farming valleys including the Tadmor, Baton and the Dove, the mighty Motueka River flowing scenically through the valley, and the pristine, spiritual energy of Te Puna o Riuwaka, along with nationally significant and scenic estuaries and the Motueka sandspit, home to many seabirds and migrating birds.

Our hāpori (communities)

The Motueka catchment has around 20,000 residents living in rural areas – on farms or lifestyle blocks, or in small urban settlements that are dotted around the catchment. The catchment community is diverse and independent. Many have a passion for looking after the environment, and of living sustainably off the land. Some have lived in the area for generations, making a living from the land, farming or growing.

Others have been drawn to the area more recently for its beauty, access to all the fantastic recreational opportunities the region has to offer, and/or to make a living from the land. Read about such families by clicking below.

Fenemor’s story
Judith Rowe’s story
Gwen Dodgsun story
The Baton Valley Trust

Motueka is the main urban hub of the region, with around 8,000 residents. It is located at the bottom of the catchment near the Motueka and Motuere Inlets, and on the right bank of the Motueka awa. Te Awhina marae is near the river, and as it says on the marae website:

Te Āwhina Marae stands under the two mountains; Pukeone and Tu Ao Wharepapa. The Motueka river runs swiftly, bringing life and nourishment to the district. The mana whenua iwi are Te Ātiawa and Ngāti Rārua and our wharenui is named after the ancestor Turangāpeke. (https://www.tam.org.nz/)

The settlements of Riuwaka and Brooklyn, know for their apples, pears, kiwifruit and hops along with the beautiful Te Puna o Riuwaka (the Riwaka Resurgence) are not far from Motueka, across the awa to the west. Other small settlements are found further inland in the catchment. Ngātīmoti is in the heart of the Motueka Valley with around 200 residents. Tapawera is a small but busy community based on the sheep, dairying, hops, and berry farms that surround it in the upper part of the catchment with approximately 400 residents. Tapawera has a strong community which has just started its own community led development programme.
https://tapaweracommunity.nz/.

Other small rural communities include Dovedale, Stanley Brook, Baton. Said of Dovedale:

Such was the interest in this sub-alpine area inland from the Moutere that all the sections offered were sold in one day. The prices paid were high for the times at 10-20 shillings per acre. (Dovedale | Tasman District Council)

There are many existing community groups working hard to help protect the health of the catchment, some of which have been up and running for many years, including:

Friends of Flora – https://www.fof.org.nz/

Farmers for Whio – https://www.tet.org.nz/projects/farmers-for-whio/

Motueka Valley OMB Group

Brooklyn OMB Group (or Bomb Squad) – https://motuekacatchment.org.nz/community-group-fighting-old-mans-beard-in-the-motueka-catchment/

Iwi – https://www.nrait.co.nz/our-trust/about-the-trust/, https://www.facebook.com/ohumaatu/

Keep Motueka Beautiful – https://www.facebook.com/kmb.nz.co/

Our catchment – then and now

Brief history of change and development in our catchment

The Motueka valley and surrounding environment has undergone significant change and transformation. Originally, dense forests, primarily tall trees like podocarps and beech, blanketed much of the region. Along the coastline, coastal scrub likely thrived, while higher elevations were adorned with alpine tussock grasslands.

The catchment would have been brimming with non-human species – birds, fish, insects. Some of the rivers, including the Motueka River, was originally a braided river with a wide floodplain. Wetlands and swamps occupied a large part of the lowland part of the catchment.

Early Māori were Ngāti Tumatakōrkiri who arrived in the 16^th century from the North Island. Early Māori inhabitants, including later tribes who usurped Tumatakōkiri, cleared portions of the forests, but left large areas of forest particularly most inland areas, but also around Motueka, namely Te Maatu, the Great Wood.

“… the Motueka River, which was originally a braided river system with a flood plain, rather than the single channel it is now. Harakeke and raupo were common in the lowland wetlands behind the beach ridges. Tradition describes the Motueka flood plain as an extensive and bountiful mahinga kai, replenished and fertilised by floods and supporting a wide variety of resources and cultivations.”
TE TAUIHU CASE STUDY REPORT (PDF) (ngatitama.nz)

European settlers arrived into Whakatū, Nelson in 1842 were drawn to the area’s exceptional soil fertility. This lead to the establishment of small farm settlements in the area. Settlers cleared vast expanses of forest at this time. The NZ Company also undertook considerable works to the waterways in the area, straightening rivers and draining wetlands to create useable farmland. This removal of much of the lowland forest from the catchment severely reduced the distribution and abundance of native fauna in the catchment.

The river then was a core part of people’s lives. The Motueka River was ‘…the biggest thing in our lives. We had to cross it to reach a road…it was our enemy, our playground, our bugbear and intimate friend,” wrote Colonel Cyprian Brereton. A great flood in 1877 drove many settlers off the river flats. A 20 foot wall of water came down the valley and spread out over the whole district, with most buildings in High Street being flooded.
TE TAUIHU CASE STUDY REPORT (PDF) (ngatitama.nz)

By the 1960s Motueka was New Zealand’s main tobacco growing area. The decline in the tobacco industry twenty years on led to the establishment of the pip fruit industry, especially apples, hops, kiwifruit and other crops, and the tourism and fishing industries have resulted in economic development over time.

As the Motueka River makes its journey towards the sea, it is joined by numerous tributaries. These tributaries vary in size and origin, each adding its unique contribution to the overall ecosystem of the river.

Our whenua (land) today

The rugged mountainous terrain in the headwaters of the catchment in original native forest protected by the Kahurangi National Park remains. This forest contains a wide variety of birds and other animals and is crucial for maintaining soil quality, preserving water sources, and fostering biodiversity. The soils here are a mixture of thin-infertile to thick fertile soils.

The alluvial plains in different parts of the catchment support a wide range of horticulture on young relatively fertile soils, much of which is irrigated from groundwater aquifers. Rolling and steep hill country in the lower basin contain low-fertility soils and are grazed or in plantation forest.

We estimate there are about:

860 farms within the catchment
590 plantation and woodlot owners (with over 5 ha of forest plantation).

We estimate the number of properties within the rural (including small towns) area of the catchment at 1500 and another 3500 dwellings in the town of Motueka at the mouth of the river.

There are 16 dairy farms within the Motueka catchment. Although the percentage land use of horticulture is relatively small, this industry plays an important role in the region’s economy and labour market.

The main land uses include:

Approximately 41% remains native forest
Exotic forest covers roughly 28%
Pastoral grasslands, supporting sheep, beef, and some dairy farming, occupy about 16% of the landscape
Cropping / horticulture occupies only 1% of the land
The rest (14%) is covered with urban, bare land, tussock grassland, or scrub

See this breakdown here – https://www.lawa.org.nz/explore-data/land-cover

Geology

The geology is highly diverse with clearly defined areas which include:

erodible Separation Point granites (mid-basin in Western part of the catchment)
Moutere clay-bound gravels (On hill slopes of the Moutere, Waiwhero, Orinoco and Dove, mid-basin)
ultra-mafic mineral formation (Red Hills, south-eastern headwaters, high levels of heavy metals)
old sandstone-siltstone (south-eastern headwaters), and
complex limestone, marble, igneous and calcareous mudstone (western headwaters).

Our awa (rivers and streams)

The Motueka River is the main river in the catchment. The river is 110 km long, and begins its journey high up in the mountains, originating from Maungakura/Red Hills at an altitude of 1,800 meters. From there, it winds its way through a narrow valley below Tapawera, following the foot of the (Arthur Range/Wharepapa) towards the coast. It delivers approximately 65% of the fresh water to Tasman Bay, a productive and shallow coastal body of high cultural, economic, and ecological significance.

Tributaries flowing into the Motueka River include:

Upper: Motupiko, Rainy, Tadmor, Glen Rae, Sherry, Wangapeka, Dart, Tapawera, Baton, Stanley Brook, Dove
Middle: Pearse, Little Pokororo, Pokororo, Graham, Waiwhero, Orinoco.
Lower: Shaggery, Little Sydney, Brooklyn.

The Motueka River and tributaries are valued for a number of reasons including:

Cultural Significance

For local Maori, the Motueka River, and its tributories, along with the Riuwaka River and Te Puna o Riuwaka s are taonga and of significance to tangata whenua. Wai is the source of life, Māori have ancestral relationships with the river, and seek to protect the mauri of wai. The protection and enhancement of freshwater is one of the highest priorities for tangata whenua iwi of Te Tauihu o te Waka-a-Māui.

Wai is a living expression of the first atua who are inextricably and continuingly present in the natural environment – wai is forever the tears of Ranginui, falling as rain and mist, and it is the life blood of Papatūānuku, running through the land and nurturing and connecting all living things. Wai and all the life it sustains are precious taonga, generous gifts from ngā atua kaitiaki – Tangaroa, the spiritual guardian of wai, and Tāne Mahuta, guardian of the forests, trees, plants and birds.

TE TAUIHU CASE STUDY REPORT (PDF) (ngatitama.nz)

“The wairua of the Motueka can be described as the spiritual connection between the people and the river (and the land it travels through).”

The river is a source and practice of mātauranga and tikanga. Māori value the river for its customary use, Mahinga kai or rongoā species present, and the presence of waahi tapu and waahi taonga associated with wai. Tangata whenua indicate that there has been a gradual but discernable loss in cultural values of the river.

Ecological Importance

The Motueka River is a thriving ecosystem in its own right. It provides habitat for a diverse array of aquatic plants, fish and macro-invertebrates. Part of the river is protected by Water Conservation Order. Additionally, it supports river-nesting birds such as Oystercatchers, Black-billed gulls, Banded Dotterels, and Pied stilts, as well as threatened species like the blue duck.

Recreation and Leisure

The Motueka River is a cherished resource for recreational activities. People flock to its banks for fishing, kayaking, swimming, and picnicking, enjoying the natural beauty and tranquillity it offers. It is known for its trout fishing, and many people can be found cooling off at the different swimming spots along the river in the summer months.

Economic livelihood

Many people and businesses use the river or groundwater for water for drinking and for their crops or land, or for stock drinking water.

Community voices about our awa

People have strong connections to the catchment and the awa that run through it. Read some of their voices here when asked how they connect with the river(s):

We have a small stream on our boundary which feeds into the Tadmor. We feel this connection.

I appreciate being alongside the river’s natural environment

Guardianship, mauri of the river, conservation for water and adjoining ecosystems, as a place of nurturing and learning, as a community place.

The river is a source of life for all that lives

The river provides drinking water for sheep and birds and water for the garden.

I live beside the confluence of Wangapeka and Motueka rivers

I enjoy biking in the Motueka River catchment because of the great history, views of the mountains and beautiful patches of native bush.

Tributaries

Upper Motueka Tributaries

Beginning high in the mountains, the Upper Motueka tributaries include rivers like Motupiko, Rainy, Tadmor, Glen Rae, Sherry, Dart, Dove, Baton, and the Wangapeka, which is the largest of the Motueka River tributaries.

The Wangapeka River is one of the main tributaries of the Motueka, draining the western hills. The Sherry River, a tributary of the Wangapeka, was named for the colour of its water.

Middle Motueka Tributaries

As the Motueka River meanders through the valley, it’s joined by tributaries like Pokororo, Pearse and the Graham. These middle reaches of the river system support a mix of habitats, ranging from forested streams to open meandering channels. They provide important spawning and rearing areas for fish and serve as corridors for wildlife movement between different parts of the catchment.

Partly originating from springs, the Pearse and Baton have water temperatures that are often much colder than the main river in summer.

Lower Motueka Tributaries

Closer to the river’s mouth, tributaries such as Shaggery, Little Sydney and Brooklyn.

These lower reaches often have slower-moving waters and wider floodplains, which support a diverse array of plant and animal life.

The Riuwaka catchment

The Riuwaka River flows for 20 kilometres, entering Tasman Bay close to the town of Riwaka. For part of its journey, the river flows underground through limestone caves, returning to the open air at The Riuwaka Resurgence.

Te Puna o Riuwaka also has special mana as the source of wai ora or the waters of life and is a taonga for Ngāti Rārua. The pools have for generations been a place for whānau to come for spiritual sustenance, cleansing and healing, and the whole area associated with the Riuwaka awa is one of the most sacred sites in Te Tai o Aorere. The Riuwaka is also associated with Tāmati Parana, a revered tohunga who utilised the healing powers of the river stones. These stones continue to be of great significance today for healing purposes.

Wetlands and lakes

Only 2% of wetlands existing in the catchment. Although limited and vastly reduced in number and area, these remaining wetlands play a crucial ecological role, with notable examples like the Waiwhero wetland which is the largest wetland in the catchment at 16 hectares. Efforts to create artificial wetlands alongside the Motueka River aim to restore lost habitats. This is something being done by Tasman District Council, but also by private residents.

The only natural lakes in this catchment are very small and alpine/sub-alpine within the conservation estate e.g. Luna Lake in the upper Wangapeka catchment.

Groundwater

Groundwater in the Motueka area is primarily sourced from alluvial gravels, forming what is known as the Motueka Gravel Aquifer. The aquifer’s storage capacity varies, with thinner layers at the inland margins of the plains and thicker, more permeable layers in the central plains area.

The hydrogeological system of the Motueka area is complex, with multiple layers of interconnected aquifers underlying the landscape. In particular, the nationally recognized Mt Arthur karst cave system to the west contains a high-yielding aquifer comprised of three interlinked layers. These aquifers interact with surface water bodies like the Motueka and Riuwaka rivers, receiving recharge from rainfall, and river flows.

Groundwater in the Motueka area is used for various purposes, including domestic supply, agricultural irrigation, and industrial processes. However, increasing demands from population growth, agricultural intensification, and climate variability pose challenges for sustainable groundwater management.

Coastal receiving environments

The Motueka-Riuwaka Delta has four unique estuaries: Riuwaka, Ferrer Creek, Motueka River, and Motueka. These are all shallow, short residence estuaries. Despite the extensive modification of these estuaries such as removal of salt marsh, the Motueka estuary is considered nationally significant.

How healthy are our waterways?

The Cawthron Institute developed a scoring method to determine the health of the stream using what they called “The National Rapid Habitat scoring assessment”. They say a healthy stream is defined by:

Low levels of fine sediment (you can assess this by shuffling your feet in the stream or by assessing how much of the stream bed contains sediment)
A non-eroding bank
Plenty of habitat for macro-invertebrates and fish.
Shading cover, especially on the northern side, with vegetation with good diversity in a sizeable riparian strip.
A water course with pools, with of variety in flow depths and the stream meanders with curves.

It is important to appreciate that while some sub-catchment water quality attributes may indicate very good water quality, frequently downstream sites and estuary water quality is relatively poor and catchment-scale contaminant reductions are needed to meet downstream and estuary water quality objectives.

This classification does not really take into account iwi values and cultural health aspects. This includes:

The status of the site – whether it is of significance to Māori such as a wāhi tapu site
Mahinga kai – this includes whether the river is healthy enough to gather kai from, or whether appropriate species are present, what the access is like for Māori to to this
Stream health – encompassing a holistic view of the health of the stream including surrounding land use, riparian use, channel modification, habitat, flow, clarity, quality etc – How to assess the health of streams and waterways (PDF) – Ministry for the Environment

The following sections give a summary of the health of the waterways in the Motueka Catchment, recognising that we don’t have full information about all waterways.

See the Freshwater monitoring thematic group page for more about action being taken to address information and monitoring gaps and bring community citizen science into water monitoring in the catchment.

River Health

Water quality is generally good across the catchment, with some examples of excellent habitat and very low levels of contaminants in a number of the larger rivers. For example:

Water clarity in the upper Motueka and Riuwaka Rivers is very high by New Zealand standards. The Wangapeka River is not far behind. The waterways that arise from karst springs (resurgences) of the west bank mid Motueka, such as the Pearse and Graham Rivers, also have very high water clarity.
Nutrient concentrations are relatively low compared to other parts of New Zealand
Dissolved Reactive Phosphorus is likely improving at a number of sites on the Motueka, Wangapeka, and Riuwaka Rivers.

However, there are increasing nitrate levels on the Motueka River and sedimentation is a major issue which affects stream beds and aquatic habitat. This in turn impacts the receiving environments of the Motueka Estuary and Tasman Bay/Te Tai-o-Aorere. Some smaller, modified streams in pastoral catchments have elevated nitrates, water temperature, and E.coli concentrations.

These points highlight more details about concerns about river health in the catchment:

A reasonable proportion of small, low-gradient unshaded streams have poor water quality. In summer, water temperature is high, dissolved oxygen is low and there are few macro-invertebrates, often with high suspended sediment concentrations. This is particularly the case with streams draining pasture and horticultural land.
Fine sediment discharges are a problem in the catchment particularly during flood events. It amplifies the effects of other contaminants such as disease-causing organisms and nutrient issues, as these contaminants bind to the sediment and then prevail in the stream bed for much longer. Fine sediment clogs the gills of insects and fish, reduces visibility for hunters, and also ends up in the estuary in storm events and affects the seabed. The Motueka Catchment contains an area of highly erodible granite sands. Sediment is coming from both steep farmland and from forestry during harvest.
Water temperatures (>18C) are high enough to adversely affect fish and invertebrates in a number of places in the main river and tributaries (particularly from the left bank) over summer. Low oxygen levels occur in some low gradient small tributaries with excessive aquatic weed growth and lack of shading.

Nitrate concentrations are rising in the Motueka River although they are still at reasonably low levels. This is the case at Woodstock, and the Gorge site even though 98% of the land area of the catchment upstream is in a natural state. However, total oxidized nitrogen is rising six times faster at the Woodstock site and appears to be degrading faster in the last 5-10 years. Filamentous green algae growth is already an issue at times in this river and is likely to get worse if this trend continues. Nitrate concentrations are highest in the Woodlands and Thorpe Creeks in Motueka (based on only a few samples).
The macro-invertebrate index (MCI) is reasonably poor on the Motueka River at Woodstock and is ‘very likely degrading’. The same pattern is occurring at the Gorge, so this could be partly related to natural causes such as the runoff of heavy metals from dissolution from the ultramafic geology in the headwaters. Interestingly the MCI is also ‘very likely degrading’ in Hunters Creek which is in native bush. This could be due to sediment discharges from pig rooting that is prevalent in this catchment. Some of the very sensitive macroinvertebrates such as the green stonefly are disappearing.
E.coli concentrations and Total Ammonia are degrading on the Motueka River including at the Gorge, the SH60 Bridge and at Woodstock. Each of these sites in in the A Band except for E.coli concentrations which are in the Band B at Woodstock.
E.coli concentrations are below national bottom lines on the Sherry River but are likely improving. E.coli concentrations have dramatically improved since the early 2000’s when cows were progressively removed from the waterway and then more latterly when a dairy farm was converted to hops. However, nitrate levels are now increasing, likely as a result of fertiliser application from horticultural use.
In relation to the Riuwaka River, despite E.coli concentrations being reasonably low, they are ‘very likely degrading’ with an unknown cause. While MCI is also acceptable, it is ‘likely degrading’ over the last 10 years. The Motueka River at Alexander Bridge and SH60 are typically swimmable over 80% of the time.
Fish passage barriers exist in the catchment. Stream habitat for fish is degraded in parts of the catchment, particularly smaller lowland tributaries. In particular, the riparian tree cover has been reduced and channel morphology made more uniform.

See information at this link for a general overview of the water quality of the Motueka catchment – https://www.lawa.org.nz/explore-data/tasman-region/river-quality/motueka-river.

You can also check swimming water quality, water quantity information.

Freshwater ecosystems

The Motueka catchment has a moderately diverse range of native freshwater fish species. It contains 20 of New Zealand’s 51 native fish species, including galaxiids, bullies, and eels. There are also five estuarine and marine fish species in the lower reaches, including black flounder, kahawai, yellow-eyed mullet, stargazers and cockabully.

Of the native fish species in Tasman, more than half (currently 12) are listed as At Risk or Nationally Vulnerable by the Department of Conservation. This high proportion of species with declining populations is largely due to broad-scale land use changes which has led to the degradation of fish habitat in waterways.

Water quantity

Some of the Motueka/Riuwaka Plains areas face significant water shortage and allocation problems during the summer months. Although groundwater quality is good, it is unsecured which poses a health risk if used for drinking water. The Dove catchment is over-allocated.

Some tributaries have very low flows or dry up naturally in summer. When flows in the river drop over summer, particularly upstream of the Wangapeka River, water takes reduce, impacting economically on landowners. There are concerns around the environmental effect of increased water takes. Landuse such as forestry may be affecting water flows in the river and the monoculture of hops particularly in the Tapawera Plains is a cause for concern re demand on water supply at specific times.

Cultural Health

Mauri is a word in Te Ao Māori representing the essence or life force of all living things, and a link between the spiritual and physical worlds. According to Māori, all water bodies have their own mauri which gives them distinct personality or mana. Particular practices must be observed to maintain harmonic balance and prevent degradation of the mauri of the water.

…in the late 1880s, the local government altered the course of the [Motueka] river and [associated smaller streams] dried up… Te Atiawa lost both their fisheries and their fresh water for their domestic use… Change continued in the twentieth century. The Motueka and Riwaka rivers still run to the sea… but their wairua and water quality have been compromised.

Waterways, tributaries, creeks, wetlands and swamps have for the best part been drained of their valuable resources and replaced with culverts, water pump stations, cattle fords and dams.

Iwi/hapū groups from the Motueka Catchment adapted a cultural health index and applied it at sites throughout the Motueka and Riwaka catchments. The Wangapeka River received the highest score of all the sites sampled in the Motueka catchment, due in part to clear water, riparian tawhai/beech forest, and a high percentage of native forest in the catchment upstream. The Motueka main stem achieved low-moderate scores, due to lack of native or food-bearing trees along the banks, gravel takes, and only moderate percentages (~35%) of native bush in the catchment. The Dove River scored very low because of large water takes (>50% of the flow during low flow periods), limited native riparian vegetation, and a low percentage of native forest in the catchment.

Ngāti Tama, Ngāti Rārua & Te Ātiawa are now looking to re-assess cultural health with the help of Tasman Bay Guardians. developing Wananga and cultural health assessments projects with their whānau.

Other issues in the catchment

The river floods at times and floods are expected to be bigger and more frequent in the future. Floods cause a lot of damage particularly the debris carried in the flood flows.

Rock walls put in to stabilise riverbanks reduce fish habitat.

Removal of willows with no replacement plantings has led to erosion of riverbanks.

Gravel is building up in some places which increases flood impacts on riverbanks.

The large reduction in areas of bush and wetlands in the catchment. Biodiversity and riparian plantings are threatened by weed pests such as old man’s beard (OMB). Predator animals (possums, rats, pigs) are impacting on tree and bird populations.

Climate change is expected to impact the catchment via rising temperature and more extreme flood and drought events and communities along the River with support from TDC will need to work together to become more resilient in the face of this challenge.

More information

For detailed information on the Motueka catchment, you can refer to the following sources:

Much of the information provided here is condensed from these sources.