The New Zealand Institute
| Grade | NZ Rank | Trend | Latest Value | 2015 Target | |
|---|---|---|---|---|---|
| C | Not available | Bad | 0.99 mg/L nitrate | 1.00 | 'Polluting our rivers to feed the world' |
Although water covers 75% of the earth’s surface, 97.5% of that is salt water. The 2.5% that is fresh water is mostly locked up in icecaps or glaciers so less than 1% is accessible for human use.
Globally, the supply of quality freshwater is coming under increasing pressure as populations grow, countries industrialise, and water deteriorates through pollution or declines through use that is too fast for the rate of replenishment. Since 1950, global water use has more than tripled. Based on current trends over the next 20 years humans will use 40% more water than they do now (WaterAid UK statistics referencing the United Nations Environment Programme). Assuming continued economic and population growth, by 2030 water supplies will satisfy only 60% of global demand and less than 50% in many developing regions (Boccaletti, Grobbel & Stuchtey). Water is used locally so some places can be badly affected by scarcities or pollution while other places in the same country are not.
Access to clean fresh water is critical for New Zealanders. We need water to drink and wash, to grow the plants that sustain our agricultural economy and food supply, and for industry. Clean rivers and lakes are important for recreation and tourism. Lincoln University’s research over a decade reveals the state of the environment is generally perceived as very good by New Zealanders, although freshwater, of all the resources considered, rates the lowest. There is a higher level of concern, and some negativity, about the state of local lowland streams. An increasing amount of blame is being placed on farming for damage to freshwaters (Hughey, Cullen & Kerr).
Several indicators are used to measure the quality of water including water clarity, bacterial content, taste or odour, and the level of nitrate (dissolved form of nitrogen) in water. The nitrate level in water has been selected as the overall measure of water quality as it is a good indicator of the health or degradation of freshwater. Nitrates are required within an ecosystem but high levels can result in excessive algal blooms and weed growth. That in turn can cause oxygen depletion that affects fish and other aquatic animals and reduces the recreational and aesthetic value of water bodies. Elevated nitrate levels indicate the potential presence of pollutants such as faecal pathogens and pesticides. Nitrate levels also indicate New Zealand’s performance in addressing non-point source pollution from diffuse sources such as polluted runoffs from agriculture land draining into rivers, growing and intensifying dairying activities, animal waste, septic tanks, fertilisers and local council sewage treatment systems.
A blood condition in infants commonly known as ‘blue baby syndrome’ is also linked to excessive levels of nitrate in drinking water. To eliminate that risk suppliers of drinking water are required to monitor and manage nitrate levels.
You can view the video on the Piako river Sir Tindall mentions by going to: http://www.ziln.co.nz/program_detail.php?program_id=914&channel_id=84
New Zealand is well endowed with a large supply of fresh water. There is relatively high and reliable rainfall which replenishes our streams, rivers, lakes and groundwater. Based on 2007 data, New Zealand ranked 4th out of 30 OECD countries on a per capita basis for the size of its renewable freshwater resource. Less than 5% of New Zealand’s renewable freshwater resource is allocated for use, much less than in many other countries (MfE website).
New Zealand’s National River Water Quality Network (NRWQN), is operated by the National Institute of Water and Atmospheric Research (NIWA). Since 1989 77 sites on 35 rivers throughout New Zealand have been monitored. There are 44 North Island and 33 South Island sites on rivers which drain about half of New Zealand’s land area. Each river is surveyed monthly and several variables are measured including bacteria, nutrient concentrations such as nitrogen and phosphorous, clarity, temperature and dissolved oxygen levels. Algae is monitored monthly and annual monitoring of macroinvertebrates occurs at 66 sites.
As shown in Figure 1, in the 5% of rivers with the highest concentration of nitrates, the level of nitrates increased from a low in 1993 of 0.58 milligrams per litre (mg/L) to a high in 2004 of 1.00 mg/L. The nitrate concentration reduced slightly thereafter and reached 0.99 in 2007.
Over 1989 to 2007 38% of the 77 monitored river sites had a meaningful increase in nitrate levels (where the trend is both statistically significant and environmentally meaningful) as shown in Figure 2. Nineteen percent of monitored sites had a significant and meaningful decrease in nitrate levels. About one third (36%) showed no significant water quality trend.
Lakes and groundwater are also affected by nutrient pollution. Over 2005-2009 NIWA monitored nutrient levels in 112 lakes reporting 44% of the lakes had high or very high levels of nutrients present, meaning the water quality is degraded. These lakes are most commonly located in the north of the North Island or in the lowlands of the South Island. Eleven of the lakes are classed as ‘hypertrophic’ meaning they are saturated with nutrients and their water quality is extremely degraded. In these lakes algal blooms are common and the health of aquatic animals is often at risk. While recreation such as sailing may occur on the surface of these degraded lakes, activities such as swimming are restricted due to prolific weed growth and poor water clarity. Thirty-three of the monitored lakes had low or very low levels of nutrients present and were most commonly found in the high country of both islands.
When the monitored lake results are extrapolated to all New Zealand lakes, out of 3,820 lakes larger than one hectare 32% would be classed as degraded and 43% would have low or very low levels of nutrients present.
Figure 3 shows that for 67 lakes where trend data over 2005-2009 was available there were twice as many deteriorating lakes (19) as improving lakes (8). Eighteen of the 19 lakes with declining quality were in areas with native or pastoral land cover. Fifteen of the 19 lakes with declining quality were glacial lakes located in the Canterbury region.
Figure 3 also shows that between 1995 and 2008 among the 886 groundwater sites monitored 13% had worse (increasing) and 20% better (decreasing) levels of nitrate concentrations. In 13% of sites median concentrations of nitrate exceeded the Australia and New Zealand Environment Conservation Council toxicity trigger value for the protection of aquatic ecosystems. Between 1995 and 2006 more than one third (39%) of groundwater monitoring sites had above natural nitrate levels (Daughey & Wall, 2007).
Other research shows that despite increasing concern over the state of freshwater, little success has been made in halting the decline in native freshwater fish. Thirty-four of the 50 native fish in New Zealand are now classified as threatened or at risk of extinction compared with 25 in 2005. (Allibone et al.)
The amount of water being used compared to water availability varies widely by region. Figure 4 shows the water stress ratio for each region based on the total water allocation divided by the total water resource available. Canterbury and Otago are the two most water stressed regions with rapid increases in allocations over the seven year period. Water stress levels are also increasing in other regions. The Land and Water Forum identified in its report A Fresh Start for Freshwater (2010) that “water scarcity is becoming a serious issue in many places depending on seasonal and climatic variations with many catchments over-allocated and others fully allocated or approaching full allocation” (p.16). However compared with many other countries water stress levels in New Zealand remain low.
In summary the data shows while New Zealand has many water sources not affected very much by pollution, many are affected. Improvements in water quality are observed in some places but the overall pattern is that many rivers, lakes and groundwater continue to be polluted and are deteriorating.
Expansion and intensification of dairying activities has been identified as a driver of reduced water quality in some regions in New Zealand. In response the Clean Streams Accord was agreed in 2003 between the Ministry of Agriculture and Forestry, Ministry for the Environment, Fonterra and Local Government New Zealand (on behalf of regional councils). The Accord aims to minimise the impact of dairying on New Zealand’s streams, rivers, lakes and wetlands so that they are suitable, where appropriate, for fish, drinking by stock and swimming. It specifies targets to keep dairy cattle out of streams, lakes and wetlands, to treat farm effluent, and to manage the use of fertilisers and other nutrients. Progress updates indicate that most of the planned actions are being undertaken but not all.
Nationally 65% of dairy farmers’ effluent was considered appropriately treated and discharged in 2009/10, up from 60% in 2008/09 after a drop from 64% in 2007/08. The target is for all dairy farms to comply with resource consents and regional plans, so more needs to be done to lift compliance, particularly in regions with significant non-compliance. Given the persistent levels of non-compliance, concerns have been raised about the effectiveness of self-regulation with some advocating an enforceable rules-based approach.
Much of the regulation and monitoring of water quality is currently the responsibility of local government. That has advantages because those conducting the assessments and establishing the guidelines have local knowledge. However different regions may apply different standards and those charged with management may not have the necessary scientific expertise.
The aggregate result of different decisions being made at the local level may affect environmental and economic outcomes at the national level.
To more effectively manage freshwater nationally, a National Policy Statement for Freshwater Management (NPS) was proposed in September 2008 and considered by a Board of Inquiry. The Board referred its findings to the Minister for the Environment in January 2010 and also to the Land and Water Forum that had been established in 2009. Prior to making decisions on the proposed NPS, the government sought the outcomes of the Forum’s review into how water is managed in New Zealand and recommendations for reform.
In its September 2010 report the Land and Water Forum identified a set of outcomes and goals along with 53 recommendations for change. These included changing governance arrangements, quickly promulgating a NPS, setting national objectives and standards, improving water allocation, providing greater flexibility in transferring water permits, addressing irrigation, storage, hydro projects and urban water services issues and improving the science and knowledge required for water management. After wide public consultation the Forum’s final report was released to Ministers in April 2011.
The Environment Minister and Agriculture Minister announced the government’s fresh water policy package in May 2011. It included:
In addition an investment of $9.3 million in two freshwater research projects was announced in June 2011. One project over six years will develop innovative methods for characterising and mapping New Zealand’s groundwater systems. The second project will develop a visual tool (the water wheel) and process for water users to individually and collectively understand how their decisions impact on water quantity and quality.
The Land and Water Forum was subsequently engaged by government to report by May 2012 on methods, tools and governance arrangements for setting limits for water quality and quantity, and by November 2012 on methods and tools on allocation.
Reaction to the government’s freshwater policy package has been mixed. There is support for the overall direction provided but concerns about whether the approach to development and growth will improve environmental outcomes. Federated Farmers is enthusiastic about the government’s irrigation acceleration fund and the potential Crown equity investment for water infrastructure schemes. Others including the Environmental Defence Society, Fish & Game NZ, Forest & Bird and NZ Freshwater Sciences Society have questioned whether the policy changes are sufficient to avoid further degradation of water quality and biodiversity in streams, lakes and rivers.
A Cawthron Institute report commissioned by Fish & Game NZ reviewed the NPS comparing it with the January 2010 Board of Inquiry recommendations. It identified that the NPS effectiveness is critically dependent on how, and how quickly, regional councils and stakeholders respond. As no national minimum standards have been set for all water bodies and there is a long period for regional councils to set these and implement methods to achieve them, the report suggests it is likely that water quality will decline for several more years. Contentious plan changes take three to five years to develop and finalise, and the NPS allows councils to take up to 2030 for all the changes required, including addressing the effects of diffuse discharges such as those from animal farming.
With new subsidies for irrigation schemes likely to result in further intensification of land use there is a risk of declining water quality associated with the off-setting provided for i.e. some rivers and lakes can further degrade within a region as long as there are plans for others to improve. A review of offsetting found that the approach typically results in developments proceeding but insufficient improvements in the quality of the ‘off-set’ water bodies (Walker et al., 2009).
In early 2011 the Ministry for the Environment commissioned work to develop Single Environmental Indicators for river, lake and recreational water quality that could be reported at a national level, and a scientifically sound and consistent national scale State of the Environment freshwater monitoring programme. Since then the government has released a discussion document, Measuring Up, seeking public submissions by mid-October 2011 on a proposal to make the Parliamentary Commissioner for the Environment responsible for reporting every five years on the State of the Environment. This would include water quality reporting and ranking lakes and rivers from the cleanest to the dirtiest, along with identifying which are improving and deteriorating.
New Zealand has a very large freshwater resource and much of it remains high quality. There has been some progress made in addressing point source discharge, and some rivers, lakes and groundwater sources are improving.
However, deterioration of the quality of rivers is continuing so interventions to reduce pollution are not yet working. The quality of the resource is a B reflecting New Zealand’s abundance of high quality water but the grade is a C because of the increasing nitrate pollution per litre of water.
Implementing policy that is judged strong enough to reverse the adverse trend would improve the grade to a B.
Hold the average nitrate levels in the worst 5% of rivers, at or below 1.00 milligrams per litre.
Figure 1: Data sourced from Nitrate trends in rivers in the National River Water Quality Network, 1989–2007 an analysis prepared by Ministry for the Environment from data supplied by NIWA, retrieved 17 March 2011 from http://www.mfe.govt.nz/environmental-reporting/freshwater/river/nutrients/nitrate/table-trends.html. The nitrate monitored is nitrate-nitrite nitrogen (also known as oxides of nitrogen).
Nitrate trends in rivers provide a national picture of river water quality in New Zealand. The 5th and 95th percentiles represent the lowest and highest 5 percent of results. The levels of nitrate are measured monthly at 77 sites on 35 rivers around New Zealand in the National River Water Quality Network (NRWQN) operated by the National Institute of Water and Atmospheric Research (NIWA). The sites monitored provide information regarding specific sections of a river and not the whole river. The catchments (of fairly large rivers) within the NRWQN are somewhat weighted towards the uplands rather than the lowlands where water quality is generally lower.
Figure 2: Base data sourced from Nitrate trends at national network sites, 1989-2007 an analysis prepared by Ministry for the Environment from data supplied by NIWA, retrieved 16 February 2010 from http://www.mfe.govt.nz/environmental-reporting/freshwater/river/nutrients/nitrate/map-trends.html. The nitrate monitored is nitrate-nitrite nitrogen (also known as oxides of nitrogen).
The figure shows the trends in nitrate levels between 1989 and 2007. The percentages shown were calculated by identifying the number of sites that were categorised according to their level of increase, decrease or no change in nitrates and then expressing this as a percentage of the 77 monitoring sites in the National River Water Quality Network.. An increase in nitrates is seen as a decline in water quality while a decrease in nitrates is seen as an improvement.
A ‘meaningful’ trend is both statistically significant and environmentally meaningful, while a ‘significant’ trend is statistically significant but not necessarily environmentally meaningful (i.e. the scale of the change could be very minor).
Figure 3: Changes in nutrient levels for monitored lakes are measured using the trophic level index (TLI). The TLI separates lakes into six classes of nutrient enrichment, from pristine to extremely degraded (hypertrophic). The Index considers phosphorus and nitrogen levels, visual clarity of the lakes and algal biomass. Nutrient trend information was sourced from Verberg, P., Hamill, K., Unwin, M. & Abell, J. (2010, August). Lake water quality in New Zealand 2010: Status and trends, a report prepared by NIWA for the Ministry for the Environment, retrieved 21 March 2011 from http://www.mfe.govt.nz/publications/ser/lake-water-quality-in-nz-2010/. Trends in water quality between 2005 and 2009 were assessed for 68 lakes (for one lake, the catchment land cover was not determined, so only 67 lakes are used in Figure 3).
As part of its National Environmental Reporting Programme, the Ministry for the Environment regularly reports on water quality in groundwater aquifers. Over 1995-2008 more than 900 groundwater sites throughout New Zealand were monitored. Trends in nitrate-nitrogen concentration were identified for 886 groundwater sites and sourced on 17 March 2011 from the Ministry for the Environment (2009, November). National groundwater quality indicators update: state and trends 1995-2008 http://www.mfe.govt.nz/publications/ser/groundwater-quality-trends-2008/ and the summary document Our Water Groundwater quality available at http://www.mfe.govt.nz/publications/ser/groundwater-quality-info-sheet/index.html.
Figure 4: Statistics New Zealand (2009, July). Measuring New Zealand’s Progress Using a Sustainable Development Approach: 2008-tables supporting published graphs. Table 4h Water allocation compared with total water resource, retrieved 16 February 2011 from http://www.stats.govt.nz/browse_for_stats/environment/sustainable_development/sustainable-development.aspx. Source data comes from Ministry for the Environment. Note: No 1999 data is available for Nelson or the West Coast regions.
The indicator recommended by the United Nations (2007) to measure sustainable water use is total water abstraction (use) divided by the total volume of water available. However, as good information on water abstraction is not readily available a proxy indicator is used. The water stress ratio indicates how much water has been allocated divided by the total water resource, by region. Water allocation, differs from water abstraction in that not all water allocated is actually used.
The total water resource for each region is calculated as a mean annual value over the period 1995–2005, from the Statistics New Zealand water physical stock account. It is calculated as inflow into the region (from precipitation and flows from other regions) minus the loss of water by evaporation, transpiration, and flows to other regions. This is an indirect measure of the total volume of water available as not all the water resources of a region are exploitable. For example, low or base river flows generally need to be left to support ecosystems and other in-stream uses.
Further information links for water quality
United Nations Environment Programme (2003). World Environment Day 5 June 2003, Key facts about water, available at http://www.unep.org/wed/2003/keyfacts.htm.
The World Bank, Infrastructure Indicators, Renewable internal freshwater resources per capita sourced from Food and Agriculture Organization, AQUASTAT data, retrieved 24 April 2011 from http://data.worldbank.org/indicator/ER.H2O.INTR.PC.
Boccaletti, G., Grobbel, M. & Stuchtey, M.R. (2010). The business opportunity in water conservation, McKinsey Quarterly 2010, Number 1, pp.66-74, McKinsey & Company available at https://www.mckinseyquarterly.com/The_business_opportunity_in_water_conservation_2483.
Hughey, Kenneth F.D., Cullen, Ross & Kerr, Geoffrey N. (2010, July 1). A Decade of Public Perceptions of the New Zealand Environment: A focus on water and its management, a paper presented to Session 4 Welfare & Environmental Economics at the New Zealand Association of Economists Conference 2010, available at http://nzae.org.nz/wp-content/uploads/2011/08/Hughey_et_al__A_Decade_of_Public_Perceptions.pdf. Perceptions of freshwater and its management in New Zealand: 2000-2010, a presentation on 25 June 2011 to the Royal Forest and Bird Protection Society Annual Conference 2011, available at http://www.forestandbird.org.nz/files/file/Ken%20%20HugheyForest%20and%20Bird%202011.pdf.
Ministry for the Environment, website text in Allocation compared with renewable freshwater resource, retrieved 24 April 2011 from http://www.mfe.govt.nz/environmental-reporting/freshwater/demand/resource.html.
Ministry of Agriculture and Forestry (2011, March). The Dairying and Clean Streams Accord: Snapshot of Progress 2009/2010, available at http://www.maf.govt.nz/news-resources/publications.aspx?title=Dairying%20and%20Clean%20Streams%20Accord:%20Snapshot%20of%20Progress.
Daughney, C.J. & Wall, M. (2007). Groundwater quality in New Zealand: State and trends 1995-2006. GNS Science Consultancy Report 2007/23.
Allibone, R., David, B., Hitchmough, R., Jellyman, D., Ling, N., Ravenscroft, P. & Waters, J. (2010). Conservation status of New Zealand freshwater fish, 2009 in New Zealand Journal of Marine and Freshwater Research, 44:4, pp.271-287, available at http://www.tandfonline.com/doi/abs/10.1080/00288330.2010.514346.
Land and Water Forum (2010, September). Report of the Land and Water Forum: A Fresh Start for Freshwater, available at http://www.landandwater.org.nz/land_and_water_forum_report.pdf.
Land and Water Forum (2011, April 5). Report to the Minister for the Environment and the Minister of Agriculture and Forestry, available at http://www.landandwater.org.nz/index_files/releases.htm.
Sinner, J. (2011, June 29). Implications of the National Policy Statement on Freshwater Management, Prepared for Fish & Game New Zealand. Cawthron Report No. 1965, available at http://www.fishandgame.org.nz/.
Walker, S., Brower, A.,Stephens, T., & Lee, W. (2009). Why bartering biodiversity fails. Conservation Letters, Vol 2, Issue 4, pp.149-157.
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