1.2.WATER QUALITY, ECOSYSTEMS AND HUMAN HEALTH By world standards New Zealand’s freshwater bodies are of good quality. They support a unique array of flora and fauna and are highly regarded internationally for their recreational value. However, water quality in urban and rural areas is degraded, and is coming under increasing pressure as land use intensifies. This has worrying implications for aquatic life, drinking water supplies, cultural values and water-based recreation. More than 800 sites on New Zealand’s rivers and streams are regularly monitored for water quality by regional councils and the National Institute of Water and Atmospheric Research (NIWA). Of these sites, 77 are located on 35 rivers throughout New Zealand which collectively make up the National River Water Quality Network operated by NIWA. The remaining sites, located on both rivers and streams, are part of monitoring networks operated by regional councils. State of river water (2003-2007) Country Overview - New Zealand -The state of water quality and recent trends in New Zealand’s rivers is highly variable around the country. -Areas where river water quality is significantly deteriorated include lowland areas of Northland, Auckland, Waikato, the east coast of the North Island, Taranaki, Manawatu-Wanganui, Canterbury and Southland. -Rivers in urban and rural areas generally have poorer water quality compared to native forest. Rural areas in particular are under increasing pressure as land use intensifies. Results for 2003- 2007 indicate that median levels of total nitrogen are five times worse in pasture and nine times worse in urban areas than in areas of native forest. -Also, on average, between 2003 and 2007 the water was half as clear in areas of pasture compared to areas of native forest. Clear water is important for aquatic life and recreation. -Based on the river water quality data for 2003-2007, over half of sites in Auckland, Waikato, Canterbury and Southland regions had median total nitrogen levels that exceeded New Zealand guidelines and over half of sites in Northland, Auckland, Waikato and Southland had median total phosphorus levels that exceeded the guidelines. Recent trends (1998-2007) -A previous study covering a longer time period (1989-2007) showed nationally that nutrient levels increased (deterioration in water quality) and clarity improved. -However, the recent findings show that changes in water quality at the national scale over the 10 years are varied. Between 1998 and 2007 national water quality deteriorated for total nitrogen, total phosphorus, conductivity and clarity but improved for bacterial and ammoniacal nitrogen levels. -There were, however, many river sites that showed no significant change between 1998 and 2007. For example, total phosphorus concentrations showed no significant change at 77 per cent of monitored sites around the country. -The reports also show sites where there is declining water quality. For example, 23 per cent of monitored sites showed a significant increase in total nitrogen levels between 1998 and 2007 and 26 per cent of sites showed a significant decrease in clarity. Both of which are a deterioration in water quality. -Between 1998 and 2007 national water quality deteriorated for clarity, total phosphorus, total nitrogen, oxidized nitrogen and conductivity in rivers with catchments dominated by pastoral land cover.

(Water Risk Filter)