Water Pollution In New Zealand: Understanding The Primary Causes

Water pollution in New Zealand has become a growing concern for the country's regulatory bodies and those who use and care for its waterways. Despite marketing itself as a clean, green paradise, New Zealand's water pollution problems are worsening. The causes of water pollution in New Zealand are multi-faceted and include the rapid growth of the dairy industry, urban development, industrial use, and tourism.

Dairy farming

Cows produce more nitrogen than sheep, which were previously the dominant livestock industry in New Zealand. In addition, dairy farmers are using more fertiliser to cultivate fields and are packing more animals into each parcel of land. This has led to a significant increase in nitrogen levels in waterways, contributing to water pollution.

The intensive nature of dairy farming in New Zealand has also put pressure on freshwater ecosystems. Since 2005, the increase in dairy farming rates has outstripped the ability of some Regional Councils to manage and mitigate the impacts on water quality. Fencing off waterways and riparian planting have been implemented to improve water quality, but the industry's rapid growth has made it challenging to keep up with the environmental impacts.

The booming dairy industry has polluted 95% of rivers in pastoral land, and the contamination is not limited to waterways. Dairy farming has also contributed to the destruction of native wetlands and the felling of trees, further damaging water quality. The pollution from dairy farming has affected the cultural practices and traditional uses of water bodies for indigenous Māori communities, impacting their cultural identity and wellbeing.

While dairy farming is a significant contributor to water pollution in New Zealand, it is important to note that other factors, such as urban development, industrial use, and climate change, also play a role in the declining water quality. However, with the dairy industry accounting for 3% of the country's GDP and 20% of total exports, addressing water pollution due to dairy farming is a complex issue that requires a balanced approach that considers economic and environmental factors.

Urban development

Water pollution in New Zealand is a growing concern, with an increase in population linked to a rise in water pollution. Urban development is one of the key factors contributing to this issue. The expansion of urban areas leads to an increase in pollutants entering water catchments, which has a detrimental impact on water quality.

One of the main sources of water pollution in urban areas is sewerage. Faulty infrastructure, such as broken sewers and incorrect connections, allows sewage to enter stormwater systems, contaminating water bodies. During floods, sewerage pumping stations can become overwhelmed, leading to the release of sewage into the environment. Urban development often involves increased road construction, which brings its own set of challenges. Water runoff from roads contains pollutants like zinc, copper, lead, and hydrocarbons from vehicle emissions, wear and tear, and the road surface itself, all of which contribute to water pollution.

The intensification of dairy farming in urban outskirts and lowland areas has also impacted water quality. The expansion of intensive dairy production has resulted in higher levels of nitrogen in the soil and groundwater, which eventually finds its way into surface water. This has led to an increase in nitrate-nitrogen concentrations, affecting the suitability of rivers for swimming and other recreational activities.

Additionally, urban development often leads to an increase in industrial activity, which can contribute to water pollution through industrial discharges and waste inputs. These contaminants can include heavy metals, chemicals, and other toxic substances that can have detrimental effects on aquatic ecosystems and human health.

The effects of urban development on water pollution in New Zealand are complex and far-reaching. It is important to address these issues through effective wastewater management, sustainable urban planning, and the implementation of measures to reduce industrial and agricultural pollution. By taking proactive steps, New Zealand can strive to protect its waterways and preserve the health and well-being of its citizens and the environment.

Industrial use

Water pollution in New Zealand is a growing concern, with a range of causes, one of the most significant being industrial use. Industrial processing often involves the discharge of wastewater into waterways, which has a detrimental impact on water quality. This type of pollution is known as "point source pollution", where contaminants enter the water from a single, isolated source, such as a factory discharging wastewater.

One notable example of industrial pollution in New Zealand is the Tasman Pulp and Paper Mill, which has been releasing waste into the Tarawera River since 1955. The river, nicknamed "the black drain", has suffered from severe water pollution, primarily due to this industrial activity. Similarly, Fonterra has been discharging wastewater containing milk condensate into the Tui River, a tributary of the Mangatainoka River. These types of discharges from factories and dairy sheds have been identified as a major contributor to water pollution by the Ministry for the Environment.

Another consequence of industrial activity is the increase in nutrient pollution, particularly in lowland areas. Excess nutrients, such as nitrogen and phosphorus, from agricultural and industrial sources, can find their way into freshwater ecosystems. This can lead to eutrophication, which is the over-enrichment of water bodies with nutrients, causing excessive growth of algae and other aquatic plants. While rivers can flush out these nutrients, lakes are more vulnerable as their water is held in basins for longer periods, allowing nutrient pollution to concentrate.

Furthermore, industrial development contributes to urban runoff, which is another source of water pollution. As cities expand, stormwater runoff carries pollutants such as nutrients, pathogens, and sediments into waterways. This type of pollution is known as "non-point source pollution", where contaminants enter the water from multiple diffuse sources rather than a single isolated source. Urban rivers in New Zealand are generally the most polluted, with high levels of nitrate-nitrogen and E. coli concentrations, making them unsafe for swimming.

To address these issues, New Zealand has implemented measures to reduce pollution severity. Upgrading treatment facilities has shown improvements in freshwater health, such as in the case of the Mataura River, which has benefited from reduced discharges from a nearby factory. Additionally, the government has set targets to improve water quality, aiming to make 90% of the country's large rivers and lakes swimmable by 2040. However, experts argue that more needs to be done, especially in regulating powerful industries such as dairy and tourism, to protect New Zealand's prized "clean and green" image.

Climate change

New Zealand's unique flora and fauna are also under threat from climate change. As temperatures rise, invasive species from warmer climates may outcompete native species, disrupting the ecosystem's balance. The timing of seasonal activities like flowering, breeding, growth, and migration will also be altered, further impacting the relationships between species.

The warming waters around New Zealand may encourage the establishment and spread of invasive species and diseases. Oceans are becoming more acidic, making it difficult for species like plankton, molluscs, and crustaceans to grow and maintain their shells. Warmer waters and changing currents will also impact oceanic productivity and the abundance of prey species, which form the base of the food web.

To address these issues, New Zealand has implemented policies such as ceasing the issuance of new offshore oil and gas exploration permits and promoting sustainable farming practices to reduce fertilizer use and enhance water quality. However, more comprehensive efforts are needed to mitigate the impacts of climate change on water pollution and the environment as a whole.

Human waste

One of the main sources of human waste pollution in New Zealand is the dairy industry. The country's dairy sector has experienced explosive growth since the 1990s, with the number of dairy cattle increasing by 70% since 1994 to 6.5 million. This rapid expansion has led to increased pollution from dairy farming practices, including manure, sediments, and fertilizer runoff. The intensive nature of dairy farming, with high stocking densities and heavy use of fertilizers, has resulted in elevated levels of nitrogen in the soil, surface water, and groundwater. This has contributed to the degradation of water quality, with 95% of rivers flowing through pastoral land in New Zealand now polluted.

The impact of the dairy industry on water pollution is not limited to contamination from cow manure and fertilizers. The expansion of dairy farming has also led to the destruction of native wetlands, which act as natural filters for water. Additionally, the clearing of land for dairy pastures has contributed to soil erosion, with sediments washing into rivers and lakes and changing fluvial systems in New Zealand's waterways.

It is important to note that human waste pollution in New Zealand is not solely attributed to the dairy industry. Urban areas also contribute significantly to water pollution, with stormwater runoff carrying pollutants such as nutrients, pathogens, and sediments into waterways. Additionally, tourism can bring about waste that affects the quality of the water.

To address the issue of human waste pollution, various initiatives have been implemented. For example, Fonterra, New Zealand's largest dairy company, instigated the Dairying and Clean Streams Accord to limit stock access to waterways and promote sustainable farming practices. Fencing off waterways and planting native vegetation have been shown to improve water quality by intercepting runoff and enhancing the growth of planted zones.

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