The 1997 report, The State of New Zealand’s Environment 1997, concluded that:
The main pressures on water flows have been from drainage and channelisation (which have reduced wetlands and altered the natural character of rivers including lowland aquatic habitats), deforestation (which has intensified flooding and sedimentation in steep catchments), and increasing demand for urban water supplies, livestock and irrigation. …
Responses to water flow problems that historically focused on flood control and drainage works downstream and on increasing the supply of drinking and irrigation water are now looking more to whole catchment approaches involving afforestation and water conservation. …
The main sources of pressure on water quality are non-point source pollution (from diffuse pasture runoff of animal wastes, fertiliser and sediments as well as runoff of pollutants from paved surfaces in urban areas) and point source discharges (e.g. from factories and sewage outfalls). …
The quality of our water is high by international standards, except in some low-lying rural streams and small lakes, some shallow groundwaters, and some piped water supplies. …
Responses to water quality problems have successfully focused on improving point source discharges (from sewage, factory, and dairyshed outfalls) but the more difficult and pervasive problem of non-point source discharges has yet to be addressed and will require changes in land management.
(Ministry for the Environment, 1997, chapter 10.)
Increasing demand for freshwater
Increasing demand for freshwater was identified in 1997 as one of the main pressures on water quantity and flows. Two national surveys since 1997 have confirmed that demand is increasing (it rose 50 per cent between 1999 and 2006), primarily in response to large increases in irrigation. This is particularly evident in areas that are already short of water.
While water is generally in good supply in most regions, many large river and aquifer systems are now fully allocated (that is, no further water can be taken from them without causing environmental harm or affecting existing users). The increase in demand has prompted consent authorities to put greater emphasis now than in 1997 on the management of water takes.
Protecting New Zealand’s water bodies
Water conservation orders continue to be used as a mechanism to protect New Zealand’s water bodies by placing restrictions or prohibitions on water takes, discharges, and other uses. Six water conservation orders have been gazetted since 1997, bringing the total to 14. Orders have been gazetted in the last decade for the Kawarau (1997), Mataura (1997), Buller (2001), Motueka (2004), Mōhaka (2004), and Rangitata (2006) rivers.
Pressures on water quality
Water quality in New Zealand is still generally good by international standards, and a large proportion of our water resources remain free of land-use pressures. Nevertheless, water quality continues to decline in areas that are dominated by agricultural and urban land use.
A key source of pressure on water quality in New Zealand in 1997 was identified as point-source pollution (for example, discharges from factories and wastewater treatment plants). While discharges from point-sources remain a significant influence on water quality in some areas, at the national level this source of pollution has largely been addressed through improved management of discharges from sewerage plants, meatworks, and farm effluent ponds. This is illustrated by a steady reduction in the levels of organic wastes in rivers.
Today, the primary pressure on the quality of our freshwater is intensive agricultural and urban land use. Increasing pollution from non-point-sources, such as diffuse run-off from pasture and from paved surfaces in urban areas, poses the greatest challenge for water management in New Zealand.
As was the case in 1997, the poorest water quality is found in streams and rivers, small lakes, and shallow groundwaters in modified catchments. While the levels of nutrients in our most polluted rivers are only about half the OECD average, nutrient enrichment has increased in some water bodies in catchments that are subject to intensive land use. In particular, there has been a nationwide pattern of increasing levels of total nitrogen and dissolved phosphorus in rivers in the national monitoring network.
Improving land and water management
In 1997, it was noted that management responses to the pressures on water quality from intensive land use and non-point-sources of pollution had been limited. Since then, local government, central government, and industry have invested significant resources in policy and education programmes and other initiatives that emphasise improved land and water management. The more important management responses of the last decade are discussed below.
Integrated approaches to freshwater management
Since 1997, there has been a shift at a regional level towards a more integrated approach to freshwater management. Many councils now have integrated land and water plans (within their regional plans), which put greater emphasis on protecting water quality and environmental flows through sustainable land use. For example, the Bay of Plenty Regional Council has a Land and Water Plan and the Manawatū–Wanganui Regional Council has a proposed ‘One Plan’.
In the last decade, local government has also placed greater emphasis in freshwater management, developing partnerships with community groups (including land owners – see box ‘Local action on riparian planting in Taranaki’), industry, and central government. Council-led programmes to protect and restore the water quality of Lake Taupō and the Rotorua Lakes are examples of this integrated approach (see box ‘Local action to protect water quality in Lake Taupō and the Rotorua lakes’ in the ‘Current state and trends’ section of this chapter).
Local action on riparian planting in Taranaki
Taranaki Regional Council is one of many councils working with farmers to develop sustainable land management and riparian planting plans. Up to June 2007, 12,400 kilometres of stream bank and 60 per cent of all dairy farms in the region were covered by riparian plans. By the same date, more than 1 million plants had been provided to farmers by the Council, at cost, for land and riparian planting.
Riparian planting on a stream in Taranaki.
Source: Courtesy of Taranaki Regional Council.
Sustainable Development Water Programme of Action
In 2003, the Sustainable Development Water Programme of Action was established by central government. The focus of the programme in 2007 is developing a national policy statement on freshwater, as well as two national environmental standards. One of these standards is intended to ensure appropriate methods are used to set ecological flows (that is, the minimum flow needed in a river to support aquatic ecosystems). The other standard will make measurement of significant water takes (that is, measurement of actual water use) mandatory.
Improved management by primary production sector
Since 1997, the main primary production sectors in New Zealand (dairy, horticulture, forestry, and the arable food industry) have produced or substantially revised their sustainable management strategies and environmental codes of practice. As well as setting targets and codes of practice for minimising ecosystem damage from sector activities, these strategies identify research and development needs within each sector to improve environmental sustainability.
Specific objectives for protecting water quality and flows include research into agrichemicals and nutrient run-off, on-farm mitigation and planning tools (such as nutrient and water budgeting), and forest harvesting techniques.
The 2003 Dairying and Clean Streams Accord is another example of an industry-led approach to improved land use and water quality management (see box ‘More about the Dairying and Clean Streams Accord’).
More about the Dairying and Clean Streams Accord
A voluntary agreement, the Dairying and Clean Streams Accord, was signed by Fonterra Co-operative Group (the largest dairy company in New Zealand), regional councils, and the Ministers for the Environment and of Agriculture and Forestry in May 2003. The accord’s aim is to achieve clean, healthy waterways in dairying regions.
The accord sets practical targets for farmers; for example, that ‘50 per cent of regular stream crossing points are to have bridges or culverts by 2007 and 90 per cent by 2012’. This target has already been met, according to annual progress reports, while there has also been a steady increase in the number of waterways that stock have been excluded from (up from 67 per cent in 2003–2004 to 75 per cent in 2005–2006, with the same targets as for stream crossing points). However, the level of non-compliance of discharges of dairyshed effluent (33 per cent) falls significantly short of the target set (Ministry for the Environment, 2007).
Guidelines and standards for freshwater management
Various non-regulatory guidelines and standards have been published since 1997 to help resource managers assess the quality and quantity of New Zealand’s freshwater. These include guidelines to protect ecosystems and the recreational and aesthetic values of freshwaters, guidelines to assess the risk of human disease from recreation (for example, swimming) in fresh and coastal waters, and drinking water standards to set maximum acceptable levels for chemicals and bacteria in drinking water (see box ‘Government action to manage freshwater quality’ in the ‘Current state and trends’ section of this chapter).
To incorporate Māori values more fully in freshwater management, a Cultural Health Index has been developed. The index provides additional information on stream health by drawing on local knowledge about waterways (see box ‘More about iwi monitoring of freshwater: Cultural Health Index’).
The Cultural Health Index for Streams and Waterways (CHI) is a tool developed by Ngāi Tahu, and supported by the Ministry for the Environment, Te Rūnanga o Ngāi Tahu, and Ngāti Kahungunu. Its purpose is to facilitate the monitoring of waterways by Māori (Ministry for the Environment, 2003).
Developed as the result of research undertaken on the Taieri, Kakaunui, Hakatere (Ashburton), and Tukituki rivers, the CHI gives iwi/hapū the opportunity to assess and report on the cultural health of a catchment or stream in their area. The CHI provides a clear basis for iwi/hapū to assign priorities for the management or restoration of specific sites and monitor changes and improvements in them over time. It also provides a common platform for resource management agencies and iwi/hapū to discuss and incorporate Māori perspectives and values for stream health in management decisions.
The CHI works by assessing and providing a ‘score’ for three aspects of the monitored waterway:
the significance of the freshwater site to Māori
the cultural use values of the site
the health of the stream or river.
The first measure assesses whether the site is of traditional or contemporary significance to Māori. It also evaluates whether Māori would return to the site in the future given its present state.
The second measure assesses the ability of the site to sustain cultural use. To do the assessment, the CHI identifies mahinga kai species present at the site, compares them with traditional mahinga kai sourced from the site, evaluates how easy it is for Māori to access the site, and determines whether or not Māori would return to use the site in the future. The four elements are then averaged to produce a single score.
The third measure assesses stream or river health by considering eight different criteria: water quality, water clarity, flow and habitat variety, catchment land use, riparian vegetation, riverbed condition/sediment, use of riparian margin, and channel modification. The scores for each criteria are averaged to produce a final stream health score.
Training hui have been held throughout New Zealand to introduce whānau, hapū and iwi to the CHI system and to facilitate its use.
A team monitoring stream health using the Culture Health Index.
Source: Courtesy of Gail Tipa.
Other national guidelines have been published to help promote best practice and increase consistency in freshwater monitoring and management across the country. These include guidelines for monitoring algae growth and the health of freshwater macroinvertebrate (insect) communities.
Expansion of freshwater monitoring
Ten years ago, many freshwater monitoring programmes had only recently been established by councils and other agencies. Relatively few monitoring records were available to show how water quality was changing over time. Today, several monitoring programmes yield data records of sufficient length to show trends and, most importantly, distinguish natural changes from those that are likely to have been caused by human activities.
Monitoring programmes have expanded to cover a wider cross-section of water environments than those monitored in 1997 (for example, the number of lakes regularly monitored has almost doubled since 1997).
There is also greater emphasis now on using measures of aquatic biology (such as the number and health of fish and macroinvertebrates) to assess overall freshwater ecosystem health, as well as using traditional chemical and physical measurements of water quality.
Future focus for freshwater management
In the future, water pollution from intensive urban and rural land use and water allocation will continue to be the focus of freshwater management in New Zealand. Balancing the competing needs of water users – recreational users, town water suppliers, hydro-electricity generators, tourist operators, and farmers – is likely to grow in urgency.
Climate change, recognised as a cause for concern to water managers in 1997, is also likely to feature more strongly in decision-making in some areas of New Zealand, particularly for water allocation (see box ‘More about climate change and freshwater’ in the Introduction to this chapter).