Overview
The Canterbury region accommodates ~60% of New Zealand’s braided river habitats, the rivers stretch eastward from the Southern Alps through to the Pacific Ocean. The Waimakariri River flows 151km east from Mt Rolleston in the Southern Alps to central Pegasus Bay, it is a braided- river with migrating channels that were once highly dynamic. Introduction of foreign flora such as the willow tree and the development upon the Canterbury Plains over the past 150yrs has put a halt on the river's natural migration. Braided rivers transport glacial outwash sediment from intermontane basins to the flat coastal plains, building up river channels that are kilometres wide and fluctuate over the coastal plains. These rivers are multi-channelled with each channel varying widely, the major channels within the river carry ~30% of the total flow whereas minor channels tend to carry ~1% of the flow. With the variation in channels, islands would react and counteract to river flow and sediment regulation, enabling them to host a diverse range of wetland associated flora and fauna species.
Geology
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Ecology
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Culture
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GeographyThe Waimakariri River flows through North Canterbury, it creates a natural border between the Waimakariri and Christchurch districts. With its dynamic behaviour, the Waimakariri River poses an unpredictable erosion and flood risk. Towns near the river are separated by a minimum of 3km to decrease the damage of frequent floods.
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Ecology
The Waimakariri River hosts a variety of native species that have been classified as declining, endangered and critically endangered. An insect species that was once thought extinct has been identified as living in this area. Biological and ecological diversity make the Waimakariri River an important wetland landmark, it accommodates a plethora of native and exotic species and provides for a range of cultural activities that exploit the river. Bird populations decrease with altitude, making their nest along the Canterbury Plains where there is low to moderate water flow and vegetation coverage. Local and distant migrant birds tend to flock to the river for breeding and feeding in spring/ early summer with little usage during autumn/ winter. Local birds have evolved to diminish impacts from flooding and predators, these include the ability to lay a second clutch of eggs once re-nested. Parents nest in areas on open areas with high visibility and aggressively defend their eggs and chicks, despite their well camouflaged eggs and the ability of chicks to feed themselves once hatched.
A variety of native creatures claim home to the Upper Waimakariri River including the lizards, fish and insects, both vertebrate and invertebrate. Lizards comprise of the McCann’s skink, which is considered not- threatened, and the Scree skink which habits greywacke scree areas confines it to remote areas and has an unknown species population. Native fish include the Upland and Common Bullies, Koaro, Common Galaxias and the Long-jawed and Alpine Galaxias all of which are affected by predators, cultural interference and river bed restrictions. Insect diversity of the area has yet to be fully researched however the highly endangered Robust Grasshopper, considered extinct until the 1980’s has been found in the Waimakariri catchment amongst the river gravels.
A variety of native creatures claim home to the Upper Waimakariri River including the lizards, fish and insects, both vertebrate and invertebrate. Lizards comprise of the McCann’s skink, which is considered not- threatened, and the Scree skink which habits greywacke scree areas confines it to remote areas and has an unknown species population. Native fish include the Upland and Common Bullies, Koaro, Common Galaxias and the Long-jawed and Alpine Galaxias all of which are affected by predators, cultural interference and river bed restrictions. Insect diversity of the area has yet to be fully researched however the highly endangered Robust Grasshopper, considered extinct until the 1980’s has been found in the Waimakariri catchment amongst the river gravels.
Vegetation along the Waimakariri River has changed over the past 5,500yrs, using pollen records there is evidence of plant species dominance. Widely accepted is there was a beech forest dominating the West of the Canterbury Plains and a podocarp/ hardwood forest covering the East prior to human settlement. Using pollen dating on sediment cores there is evidence of Coprosma, mānuka and Myrsine shrubs and sedges present from ~5,500 to ~2,600yrs ago (pre-human) in wetland regions along but not in the Waimakariri River. Hardwood trees were present on drier ground and included matai, miro, rimu, totara, kahikatea and some beech trees (black, red and mountain), ground and tree ferns were abundant. Beech trees began to dominate through the mid- late Holocene, decreasing the spread of podocarp forests. Maori arrived 700-600 years ago and began to burn wetland vegetation but not beech forests, with the burning there was a decline in wetland sedges and shrubs and an increase in ground ferns and grasses that could adapt to the new soil composition quickly. Europeans settlement of Canterbury saw the introduction of exotic plants. Poplars and willows were introduced to stabilise banks along the Waimakariri as well as gorse, broom, sweet brier, Russell and yellow tree lupin and the wilding pine. Alongside the introduction of new plants and pests that
the native fauna and flora had to adapt to, the Europeans burned and cleared native forests, grasslands and reduced wetland/ braided river habitat by 40% for farming/ grazing. Upper Waimakariri River is low-lying and rich in introduced flora species which are sparsely spread out. These species were all introduced and include small Cushion Plants, Lichen, Willowherbs and species that form mats along the ground such as Colonial Daisies. Along the plains there are now an increasing amount of riparian and wetland areas acting as drainage for runoff water, catching its associated nutrients and sediments between farms and the river.
the native fauna and flora had to adapt to, the Europeans burned and cleared native forests, grasslands and reduced wetland/ braided river habitat by 40% for farming/ grazing. Upper Waimakariri River is low-lying and rich in introduced flora species which are sparsely spread out. These species were all introduced and include small Cushion Plants, Lichen, Willowherbs and species that form mats along the ground such as Colonial Daisies. Along the plains there are now an increasing amount of riparian and wetland areas acting as drainage for runoff water, catching its associated nutrients and sediments between farms and the river.
Culture
Cultural and social uses of the Waimakariri River have changed through time from Māori reliance for food for 800yrs to the arrival of Europeans who drained the wetland for pasture and grazing land. One of Ngāi Tahu’s foundation values is the being able to establish their level of hospitality and respect when welcoming and hosting visitors, this is done by providing a bountiful produce. Ngāi Tahu originally inhabited the South Island from the North Island, by traipsing down the West Coast and then crossing the Southern Alps to reach the Canterbury Plains. The Waimakariri River provided for the Ngāi Tahu people as they followed it to the Pacific Ocean. The Kaiapoi pā (a fortified refuge) was built on the mouth of the Waimakariri River as it was a plentiful area of mahinga kai (mahinga kai- provided food, building materials and tools which could be collected and utilised using traditional Māori techniques.
The European settlement of Canterbury was led by Captain Joseph Thomas and occurred from 1850-1853 with 3,549 settlers. The settlement of Canterbury Plains brought with it a siege of forestry burning and clearing to make way for their farming and agricultural needs. The introduction of sheep and cattle to the Canterbury Plains degraded the Waimakariri River. Wetlands along the riverbed were drained to create further pasture and introduced species such as the willow and poplars took over the river banks. From the 1850’s onwards farming intensified further degrading the wetland environment. The Canterbury Plains were providing for the national economy with produce and exports, at the expense of the region's environmental capital. Farmers began irrigating and taking water from the Waimakariri River with a just-in-case approach rather than using a just-in-time approach which promotes sustainable farming practices. The change in irrigation practice from just-in-case to just-in-time showed an increase in the socio-economic capital of the river and increase in the environmental benefits by default. Culturally the Waimakariri River is being researched to identify if it worthy of being named as one of New Zealand’s rivers of national importance, which has yet to be confirmed. The Alpine Train travels beside the Waimakariri River for some time providing views on a spectacular range of wetlands, from river plains to alpine then through to the West Coast through the rainforest.
The European settlement of Canterbury was led by Captain Joseph Thomas and occurred from 1850-1853 with 3,549 settlers. The settlement of Canterbury Plains brought with it a siege of forestry burning and clearing to make way for their farming and agricultural needs. The introduction of sheep and cattle to the Canterbury Plains degraded the Waimakariri River. Wetlands along the riverbed were drained to create further pasture and introduced species such as the willow and poplars took over the river banks. From the 1850’s onwards farming intensified further degrading the wetland environment. The Canterbury Plains were providing for the national economy with produce and exports, at the expense of the region's environmental capital. Farmers began irrigating and taking water from the Waimakariri River with a just-in-case approach rather than using a just-in-time approach which promotes sustainable farming practices. The change in irrigation practice from just-in-case to just-in-time showed an increase in the socio-economic capital of the river and increase in the environmental benefits by default. Culturally the Waimakariri River is being researched to identify if it worthy of being named as one of New Zealand’s rivers of national importance, which has yet to be confirmed. The Alpine Train travels beside the Waimakariri River for some time providing views on a spectacular range of wetlands, from river plains to alpine then through to the West Coast through the rainforest.