Water is relatively abundant in New Zealand due to the temperate climate and maritime weather patterns. In recent years,

water pollution Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. ...

and draw-down of aquifers have become important

environmental issues Environmental issues are effects of human activity on the biophysical environment, most often of which are harmful effects that cause environmental degradation. Environmental protection is the practice of protecting the natural environment on t ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

Waters in New Zealand

In New Zealand, there are more than of rivers and streams and about 4,000 lakes and over 200 underground aquifers. Annual water flow is 145 million litres per person. The reliable supply of good water is an important economic advantage for New Zealand, but its quality and availability is declining.

Lakes

There are 3,820

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s in New Zealand with a surface area larger than , and 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. Hydroelectric reservoirs are common in South Canterbury, Central Otago and along the Waikato River.

Rivers and streams

Over of rivers has been mapped in New Zealand, the longest being the

Waikato River The Waikato River is the longest river in New Zealand, running for through the North Island. It rises on the eastern slopes of Mount Ruapehu, joining the Tongariro River system and flowing through Lake Taupō, New Zealand's largest lake. It th ...

with a length of 425 kilometres and the largest river by volume is the

Clutha River The Clutha River (, officially gazetted as Clutha River / ) is the second longest river in New Zealand and the longest in the South Island. It flows south-southeast through Central and South Otago from Lake Wānaka in the Southern Alps to the P ...

with a mean discharge of 614 cubic metres per second.

Waterfalls

New Zealand has many notable

waterfall A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls can be formed in severa ...

s, some of which are regularly visited by tourists.

Huka Falls Huka Falls is a set of waterfalls on the Waikato River, which drains Lake Taupō in New Zealand. A few hundred metres upstream from Huka Falls, the Waikato River narrows from approximately 100 metres across to a canyon only 15 metres across. The ...

on the

is one such waterfall. Sutherland Falls is usually regarded as the highest waterfall in New Zealand at 580 metres high but

Browne Falls __NOTOC__ Browne Falls is a waterfall above Doubtful Sound, which is located in Fiordland National Park, New Zealand. In a temperate rain forest, the falls cascade down to the fiord near Hall Arm. Heights of 619 metres and 836 metres have been ...

cascades 619 m or 836 m depending on what is considered to be the source. The Maruia Falls on the

Maruia River The Maruia River is located in the northwestern South Island of New Zealand. It is a major tributary of the Buller River, flowing for 80 km before joining the larger river eight kilometres to the west of Murchison. The Maruia River rise ...

are a relatively new waterfall formed as a result of the

1929 Murchison earthquake The 1929 Murchison earthquake occurred at 10:17 am on 17 June. It struck the Murchison region of the South Island, with an estimated magnitude of 7.3, and was felt throughout New Zealand. There were 17 deaths, mostly as a result of lands ...

Hydrology of New Zealand

The average annual precipitation for New Zealand as a whole is . In mountain portions of the West Coast, it exceeds 10 m per year. The distribution of precipitation across the country is determined by its location with the mid-southern latitudes and its topography. Seasonal differences in precipitation are substantial, regularly leading to summer water deficits in many parts of the country, though the season of greatest and least precipitation differ from region to region. The amount of precipitation also varies interannually in response to both

El Niño–Southern Oscillation El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea te ...

and

Interdecadal Pacific Oscillation The Interdecadal Pacific oscillation (IPO) is an oceanographic/meteorological phenomenon similar to the Pacific decadal oscillation The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability c ...

cycles.

Water resource use

Water resources are used for a number of purposes, including hydroelectricity generation, irrigation, and municipal water supply. Approximately 2% of New Zealand's freshwater resource is allocated for consumptive use.

Supply to consumers

The supply of water to consumers is provided by local government territorial authorities, which include city councils in urban areas and district councils in rural areas. The legal framework includes the Health Act 1956, amended in 2007, the

Local Government Act 2002 The Local Government Act 2002 (sometimes known by its acronym, LGA) is an Act of New Zealand's Parliament that defines local government in New Zealand. There are 73 territorial authorities (local districts), each with an elected Mayor and elec ...

and the

Resource Management Act 1991 The Resource Management Act (RMA) 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. New Zeal ...

Water resource management

Legislation

The

governs the use of water (and other natural resources). A

resource consent A resource consent is the authorisation given to certain activities or uses of natural and physical resources required under the New Zealand Resource Management Act (the "RMA"). Some activities may either be specifically authorised by the RMA or ...

is required for taking, damming, discharging and diverting water. There is a National Policy Statement for Freshwater Management.

Hydrological and water resource changes

In modern times, the quantity, quality and timing of water within New Zealand has been changing. Principal causes have been abstraction, impoundment, land use and land cover change, and agricultural and industrial runoff.

Pollution

Water pollution Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. ...

in New Zealand is becoming an increasing concern for environmentalists and for regulatory bodies. An increase in dairy farming is linked to an increase in water pollution, and siltation due to land clearance has affected lakes, rivers, caves and bays. There are more than 800 water quality monitoring sites around New Zealand that are regularly sampled.

Organisations

Various organisations in New Zealand are involved with water and its use. Regional Councils have the statutory responsibility for water. * Fish and Game New Zealand, a statutory body set up to advocate for recreational hunting and fishing, has taken a stance on water pollution. It started a " dirty dairying" campaign to highlight the effect of farming on water quality. *

Forest & Bird Forest & Bird ( mi, Te Reo o te Taiao), also known by its formal name as the Royal Forest and Bird Protection Society of New Zealand, is an environmental organisation specialising in the protection and conservation of New Zealand's indigenous f ...

, a long established conservation organisation, has become involved with water issues due to increasing concern about the effects of pollution on

freshwater ecosystem Freshwater ecosystems are a subset of Earth's aquatic ecosystems. They include lakes, ponds, rivers, streams, springs, bogs, and wetlands. They can be contrasted with marine ecosystems, which have a larger salt content. Freshwater habitats ...

s. * Freshwater Sciences Society aims to facilitate liaison between all persons interested in fresh and brackish water * The Hydrological Society of New Zealand was set up in 1961 to "further the science of hydrology and its application to the understanding and management of New Zealand's water resources". * Land Air Water Aotearoa was established by regional councils, research institutes and government entities to find the balance between using natural resources and maintaining their quality and availability. * The Land and Water Forum brings together a wide range of entities with a stake in freshwater and land. * The Waterways Centre, opened in 2010, was established as a collaboration between University of Canterbury and Lincoln University to address freshwater management.

References

water industry The water industry provides drinking water and wastewater services (including sewage treatment) to residential, commercial, and industrial sectors of the economy. Typically public utilities operate water supply networks. The water industry doe ...

organisation
Right to Water
– lobby group opposing water privatisation ;Journals
''Journal of Hydrology''''New Zealand Journal of Marine and Freshwater Research''
;Films

(2010)
''A Tale of Two Rivers''
The future of hydro power generation on New Zealand's West Coast (2010) {{New Zealand topics