Key points
This indicator measures the physical and chemical characteristics of our rivers and streams (such as temperature, acidity, nutrients). This tells us how suitable the rivers and streams are for freshwater plants and animals.
- River and stream water quality for ecological health is better in some parts of the Region (eg, the Upper Waikato River) than in others (eg, Hauraki and the lowland tributaries of the Waikato River), mainly because of agricultural runoff and rural land use.
- Monitoring of regional rivers over the past 20 years shows mixed results, with slight improvements in Lowland Waikato monitoring area but a deterioration in some other regional rivers (eg, upland Waikato, Coromandel). Overall, 24% of water quality measures improved at individual sites and 29% deteriorated over the period 1991 to 2010.
- Biochemical oxygen demand has improved along the entire length of the river, probably at least partly due to changes in the management of sewage and industrial wastewaters. At the same time, levels of both total phosphorus and nitrate increased at most sites along the river, probably as a result of land use changes over recent decades. Pressures from wastewaters have generally decreased over the past 20 years, but farming has continued to intensify.
- The recent increases in levels of phosphorus and nitrogen are of concern. As the region continues to grow and develop, putting pressure on the river's catchment, careful management is needed to maintain and improve the quality of the Waikato River.
Proportion of all samples collected during 2006-2010 which met the ‘excellent’, ‘satisfactory’ and ‘unsatisfactory’ standards for ecological water quality in Waikato rivers and streams
Source: Waikato Regional Council
Water quality trends in the Waikato River between 1991 and 2010
Source: Waikato Regional Council
What agencies are doing
- Environment Waikato has classified different waterbodies into different management classes. We have established these classes to manage water use and protect water quality values.
- Environment Waikato manages and requires the monitoring of resource consents to take water or discharge wastewater to rivers, or to dam or divert rivers and streams.
- We track changes in water quality for ecological health to update this indicator and to assist policy making and consent decisions.
- We support voluntary guidelines and codes of practice such as the New Zealand Fertiliser Manufacturers' Research Association's Code of Practice for Fertiliser Use - aimed at minimising fertiliser runoff.
- Environment Waikato's Clean Streams project provides advice and financial support to encourage and support farmer efforts to reduce the impacts of farming on waterways through fencing and planting waterway margins.
- We support care groups in the region that are involved in riparian management such as planting and fencing through staff time and expertise.
- Over 200 River and Us programmes involving more than 100 schools have been run.
What you can do to help
- Fence off streams, rivers, swamps, wetlands and seeps to prevent stock access.
- Plant banks of waterways to help stabilise them, trap contaminants and provide shade for aquatic life.
- Make sure dairy shed effluent irrigators are operating effectively and are moved frequently to prevent ponding and runoff.
- Avoid break-feeding or mob-stocking close to waterways, especially in wet weather.
- Join or form a Landcare group in your area.
- Install stormwater detention areas in new subdivisions to improve water quality. Find out more about activities requiring consents from Environment Waikato.
- Prevent contaminated water going into stormwater drains by washing your car on the grass, not on paved surfaces, fixing oil leaks and being careful not to put paints or solvents down stormwater drains.
More information
More detail on this indicator, including how and where this information is collected, is available here.
What we want to achieve
The community outcomes we are seeking to achieve by improving river water quality for ecological health are:
- The iconic landscapes and natural features of our environment define and sustain us. We respect and celebrate them as taonga.
- Our natural environment is protected and respected. Its ecological balance is restored, its air, soil and water quality is improved and its native biodiversity is enhanced.
- The traditional role of iwi and hapu as kaitiaki is acknowledged, respected and enabled.
- Our region’s waterways have consistently high water quality.