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Why the condition of our fresh water is important

The condition of our lakes, rivers, streams, wetlands, and groundwater is important for a number of reasons. Our economy depends on having plentiful water – agriculture, tourism, and hydroelectricity generation particularly rely on water. Having clean and plentiful water to drink is also important for our health and well-being. New Zealanders and visitors from overseas enjoy many forms of recreation that use our lakes and rivers, such as swimming, kayaking, and fishing. Our rivers, lakes, and wetlands also support many indigenous animals, plants, and ecosystems.

For Māori, rivers, lakes, and wetlands are a traditional source of sustenance and resources, as well as identity. Historically, many Māori settlements were located near rivers and lakes, reflecting the importance of waterways for food and resources, and also as transport routes. Māori regard fresh water as a taonga and essential to life and identity. Freshwater quality and flows affect the mauri (life force) of fresh water, and the availability and abundance of indigenous freshwater species for customary food gathering (mahinga kai).

Fresh water supports our economy

Rivers, lakes, and groundwater resources support our economy, particularly primary production such as agriculture, horticulture, forestry, and aquaculture (see Land chapter).

In 2014, dairy and meat exports accounted for 41 percent of the total value of merchandise exports. The relative contribution of the dairy sector to our gross domestic product (GDP) has been increasing, overtaking sheep, beef, and grain farming combined. Agriculture provides employment, particularly in rural areas. In 2013, agriculture employed more than 105,500 people, making the sector the second-largest ‘employer’ in New Zealand. Many businesses and industries in New Zealand exist because they provide products or services to the agricultural sector.

We generate much of our power from rivers and lakes, with hydroelectric generation accounting for 54.5 percent of New Zealand’s electricity generation in 2013.

Our rivers and lakes are also a major attraction for international tourists engaging in activities such as fishing, white-water rafting, and jet boating. Tourism also makes an important contribution to our economy, accounting for more than 8 percent of GDP (Ministry of Business, Innovation and Employment, 2013).

For more detail see Environmental indicators Te taiao AotearoaEconomic performance of the agricultural industry and Contribution of hydroelectricity to total electricity generation.

Fresh water supports recreation

New Zealanders enjoy a variety of recreational activities using our rivers and lakes, including fishing, swimming, and boating. We also enjoy the scenic beauty of our waterways, and the ecology they support. We want to know that our rivers and lakes are safe to swim in, and have adequate flows to support our recreational pursuits.

Water quality affects our ability to use rivers and lakes for recreational purposes. The primary risk to human health from poor water quality comes from faecal contamination of fresh water. The presence of E.coli bacteria in rivers or lakes indicates that the water is contaminated by animal or human faeces, posing a risk to infection from pathogens like Campylobacter. People are more likely to be infected while swimming than when they are engaged in activities that involve less frequent immersion (eg wading or boating). The likelihood of infection is greater because the risk of ingesting contaminated water increases when people submerge their head.

E.coli levels are highest in urban and pastoral areas, which are generally within 20 kilometres of where people live, and where people like to swim during summer. High E.coli levels are indicative of higher risks of infection for swimmers, particularly from stomach bugs like Campylobacter.

To meet acceptable guidelines for swimming during summer, E.coli levels must be below 540 E.coli per millilitre. To ensure these levels are not exceeded, the guidelines require that 19 of 20 sampling events are below this value. E.coli can spike to high levels in rivers and streams for 2–3 days after heavy rainfall or during low river flows (Davies-Colley, 2013), particularly in lowland areas. For this reason, regional councils frequently monitor popular swimming sites to assess the level of risk for recreational activities such as swimming. However, some inconsistencies in monitoring methodologies mean the data are neither representative nor comparable across all sites, and so do not meet our data quality standards for inclusion in this report as a national statistic. We are working with councils to develop more consistent monitoring and reporting of the suitability of a site for swimming at a national level. In the meantime, you can look for information about your local swimming spot on the Land, Air, Water Aotearoa website.

For more information see: E.coli levels are higher in urban and agricultural catchments section.

For more detail see Environmental indicators Te taiao AotearoaParticipation in recreational fishing.

Fresh water supports Māori well-being and identity

The physical, ecological, and cultural health of waterways is vitally important to Māori. Waterways and wetlands continue to be used for mahinga kai (a source of food and resources).

We have little data on how the state of waterways impacts on the economic, social, and cultural well-being of Māori. However, waterway health can also be assessed using a holistic approach. A range of tools are being used that take into account te ao Māori (the Māori world view) and include concepts such as mauri (life force) and ki uta ki tai (‘from the mountains to the sea’).

The National Policy Statement for Freshwater Management 2014 recognises te mana o te wai (which can be understood as ‘the quality and vitality of water’) alongside the national significance of fresh water. These developments highlight both the increasing recognition of Māori environmental values in environmental management and the significance of fresh water to Māori.

There is increasing recognition of the value of mātauranga Māori (traditional knowledge) to all New Zealanders, and researchers have devised tools to bridge the gap between mātauranga Māori and western science. For example, researchers have developed the cultural health index to assess the health of waterways from both a biophysical and cultural perspective. This assessment takes a holistic approach and combined with other methods, provides a more comprehensive understanding of the health of our waterways. The following two examples show how the cultural health index can help us understand the freshwater environment.

Using cultural perspectives to assess freshwater health

The cultural health index (CHI) assesses the health of waterways from a cultural perspective, as well as in terms of the waterway’s physical and biological characteristics. The CHI draws on information about a site’s water quality, and the experience and observations of people from iwi and hapū who have had a relationship with the waterway over generations. It assesses people’s ability to gather food or other resources (mahinga kai) from the site, and whether people from the hapū or iwi are likely to return to the site in future.

A Bay of Plenty Regional Council study (2014) of streams in the Te Arawa/Rotorua Lakes region highlighted the importance of evaluating the freshwater environment from a Māori cultural perspective. The study compared results from 31 sites that had been assessed using both scientific and cultural measures. Generally, it found a strong correlation between the measures, but it also highlighted differences. For example, the scientific view is that the effect of a contaminant will decrease as it is diluted, whereas the Māori view is that its impact will persist throughout the catchment, regardless of how much it is diluted.

In North Otago, the tribal committee Te Rūnanga o Moeraki uses the CHI to assess the condition of the Kakanui (or Kakaunui) River and its main tributaries. Over recent decades, land in the Kakanui catchment has been more intensively farmed, and the rūnanga is concerned about the water quality deteriorating. The rūnanga’s assessments of water quality in the Kakanui catchment revealed that about a third of the 16 sites were in a state that did not sustain cultural values, such as the ability to gather food and other resources. The health of one tributary, Waiareka Stream, was particularly concerning because none of the sites in its catchment sustained cultural values (Tipa, 2015).

Fresh water supports aquatic biodiversity

A number of factors affect the capacity of our rivers, streams, lakes, and wetlands to support indigenous fish and other aquatic life. The factors include flows being changed by removing or diverting water from rivers for irrigation, hydroelectricity generation, and other uses; increases in pollutants and sediment, invasive species, dams and other barriers to fish migration; and loss of vegetation around waterways.

New Zealand has 39 indigenous freshwater fish species (Goodman et al, 2014). Our indigenous fish are generally small and nocturnal, spending daylight hours under stones, logs, or overhanging branches. More than half the species migrate between the sea and fresh water to complete their life cycles. This means that barriers in rivers, streams, and lakes can have a significant impact on the abundance of fish in affected lakes and rivers. Indigenous fish are generally most abundant in streams in hilly or mountainous country, rather than large rivers in lowland areas. This is probably because these areas are less affected by human activities (Brown et al, 2015).

Seventy-two percent of our indigenous freshwater fish species are classified as at risk or threatened with extinction (Goodman et al, 2014). The risk of extinction worsened for eight species between 2005 and 2011. The Parliamentary Commissioner for the Environment (2013) concluded that our largest freshwater fish, the longfin eel, was in a steady state of decline. An independent review recommended by the Parliamentary Commissioner’s report found that, while eel numbers had generally declined between 1990 and 2000, there is evidence to suggest that the rate of decline may have slowed through the 2000’s (Haro et al, 2013).

Observations of freshwater fish communities between 1970 and 2007 indicate an overall decline in the diversity of species at the sites where observations were made.

For more detail see Environmental indicators Te taiao AotearoaFreshwater fish communitiesFreshwater plants and animalsFreshwater pests, and Changes in the conservation status of indigenous species.