Rivers of New Zealand
Encyclopedia
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
are used for a variety of purposes and face a number of environmental issues. Many of the rivers in the South Island are braided river
Braided river
A braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with high slope and/or large sediment load...
s.
Statistics
The longest river in New Zealand is the Waikato RiverWaikato River
The Waikato River is the longest river in New Zealand. In the North Island, it runs for 425 kilometres from the eastern slopes of Mount Ruapehu, joining the Tongariro River system and emptying into Lake Taupo, New Zealand's largest lake. It drains Taupo at the lake's northeastern edge, creates the...
with a length of 425 kilometres. The largest river by volume is the Clutha River
Clutha River
The Clutha River / Mata-Au is the second longest river in New Zealand flowing south-southeast through Central and South Otago from Lake Wanaka in the Southern Alps to the Pacific Ocean, south west of Dunedin. It is the highest volume river in New Zealand, and the swiftest, with a catchment of ,...
with a mean discharge of 533 cubic metres per second.
Some of the rivers, especially those with wide flood plains and stop banks, have long road bridges spanning them. The Rakaia River
Rakaia River
The Rakaia River is in the Canterbury Plains in New Zealand's South Island. The Rakaia River is one of the largest braided rivers in New Zealand...
is crossed by the longest bridge in New Zealand at 1,757 metres. The third longest bridge is the Whirokino Trestle Bridge on State Highway 1 crossing the Manawatu River
Manawatu River
The Manawatu River is a major river of the southern North Island of New Zealand.The river has its headwaters to the northwest of Norsewood in the Ruahine Ranges of southern Hawke's Bay. It flows initially eastward before turning south-west near Ormondville, flowing 40 km before turning...
.
Over 180,000 kilometres of rivers has been mapped in New Zealand.
Uses
Rivers in New Zealand are used for number of purposes. In the early Maori and European history of New Zealand the navigable rivers were used for transportation. There are 1,609 km of navigable inland waterways; however these are no longer significant transport routes.Rivers are used for commercial tourism and recreation activities such as rafting, canoeing, kayaking and jet-boating. Bungy jumping, pioneered as a commercial venture by a New Zealand innovator, is often done above some of the more scenic rivers.
Over half of the electricity generated in New Zealand is hydroelectric power. Hydroelectric power stations have been constructed on many rivers which dam the river completely, or channel a portion of the water through the power station. There is large hydroelectric power scheme in the North Island and in the South Island where water is diverted between rivers using a system of canals that is used to maximise the electricity generation.
Conservation and pollution
River conservation is threatened by pollution inflows from pointPoint source
A point source is a localised, relatively small source of something.Point source may also refer to:*Point source , a localised source of pollution**Point source water pollution, water pollution with a localized source...
and non-point sources. In the past rivers had been used for pollution discharges from factories and municipal sewerage plants. With increasing environmental awareness and the passing of the Resource Management Act
Resource Management Act
The Resource Management Act passed in 1991 in New Zealand is a significant, and at times, controversial Act of Parliament. The RMA promotes the sustainable management of natural and physical resources such as land, air and water...
these sources of pollution are now less problematic. Water abstraction, especially for irrigation, is now a major threat to the character of rivers. An upsurge in conversion of land to dairy farming
Dairy farming
Dairy farming is a class of agricultural, or an animal husbandry, enterprise, for long-term production of milk, usually from dairy cows but also from goats and sheep, which may be either processed on-site or transported to a dairy factory for processing and eventual retail sale.Most dairy farms...
is stretching water resources. Also, since dairy farming is becoming more intensified in New Zealand and requires large amounts of water, the problem is therefore being exacerbated.
Acid mine drainage
Acid mine drainage
Acid mine drainage , or acid rock drainage , refers to the outflow of acidic water from metal mines or coal mines. However, other areas where the earth has been disturbed may also contribute acid rock drainage to the environment...
(AMD) from the Stockton
Stockton, New Zealand
Stockton is a former settlement in the northwestern South Island of New Zealand in the West Coast region. It is located in the Papahaua Ranges about 30 kilometres linear distance north east from Westport....
coal mine has altered the ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
of the Mangatini Stream on the West Coast
West Coast, New Zealand
The West Coast is one of the administrative regions of New Zealand, located on the west coast of the South Island, and is one of the more remote and most sparsely populated areas of the country. It is made up of three districts: Buller, Grey and Westland...
. The Stockton mine is also leaching AMD into the Waimangaroa River
Waimangaroa River
The Waimangaroa River is located on the West Coast of New Zealand.The river passes through tussock, scrub and forested areas before draining into the Karamea Bight in the Tasman Sea. It passes through the town of Waimangaroa and is crossed by the Ngakawau Branch railway, with the rail bridge...
and the proposed Cypress Mine
Cypress mine
The Cypress mine is a proposed extension to the open cast coal mine the Stockton Mine’s operational area, to the east into the Upper Waimangaroa Mining Permit area, on the West Coast of New Zealand....
will increase this amount.
There is a high level of pollution in lowland rivers and streams that flow through urban or pastoral farming areas.
A report from the Ministry of Economic Development
New Zealand Ministry of Economic Development
The Ministry of Economic Development is a New Zealand public sector organisation tasked with promoting development of New Zealand's economy....
identified a large number of rivers as being suitable for hydroelectric power production. This report alarmed the Green Party
Green Party of Aotearoa New Zealand
The Green Party of Aotearoa New Zealand is a political party that has seats in the New Zealand parliament. It focuses firstly on environmentalism, arguing that all other aspects of humanity will cease to be of concern if there is no environment to sustain it...
and a number of environmental organisations due to the fear of an increasing loss of scenic rivers and rivers that have a high degree of natural character.
See also
- Water in New ZealandWater in New ZealandWater is relatively abundant in New Zealand due to the temperate climate and maritime weather patterns. In recent years water pollution and draw-down of aquifers have become important environmental issues.-Lakes:...
- Environment of New ZealandEnvironment of New ZealandThe environment of New Zealand is characterised by unique flora and fauna and a variety of landforms contained within a small island nation...
- Water Conservation OrderWater Conservation OrderA water conservation order is a legal ruling to protect aspects of water bodies. It may be to protect the quantity of the water itself or for any issues relating to the water body as a whole.-New Zealand:...
- Lakes of New ZealandLakes of New ZealandThere are 3,820 lakes in New Zealand with a surface area larger than one hectare. The lakes are of varying types and origins. Many of the lakes in the central North Island area are volcanic crater lakes, while the majority of the lakes near the Southern Alps were carved by glaciers...
- Bridges in New ZealandBridges in New ZealandThe bridges in New Zealand are many and varied but only date back to the beginning of European settlement in the mid 19th century.-Road bridges:Some of the longest bridges on the state highway network are:* Rakaia River bridge - 1,757 metres...
- Water safety in New ZealandWater safety in New ZealandNew Zealand has one of the worst drowning rates in the world. The New Zealand Curriculum now does not have learn to swim as an objective. This means that not as many children are being taught to swim as formerly. By 2030 New Zealand can expect 150-180 drownings per year -Deaths in New...
External links
- New Zealand Hydrological Society
- National Institute of Water & Atmospheric Research - National Centre for Water Resources
- Wild Rivers - a campaign to protect rivers
- Whitewater NZ (formerly New Zealand Recreational Canoeing Association)
- Ministry for the Environment - water information page
- League table of the suitability of New Zealand rivers for contact recreation from NIWANational Institute of Water and Atmospheric ResearchThe National Institute of Water and Atmospheric Research or NIWA , is a Crown Research Institute of New Zealand. Established in 1992, NIWA conducts commercial and non-commercial research across a broad range of disciplines in the environmental sciences...