Water quality is important for sustaining the freshwater plant and animals that live in Lake Taupō. Clear ‘bug-free’ water enhances the value of Lake Taupō as a safe place for swimming and other recreational activities. Also, the knowledge that the lake’s water quality is excellent is important to many people for aesthetic, cultural and spiritual reasons. Lake Taupō has become a symbol of near-pristine environmental conditions, and is seen as a national treasure.
In recent years the lake’s water quality has deteriorated slightly. This is an early warning that there may be issues that need managing. The change in water quality is thought to be due to land development in the catchment. By monitoring water quality, Waikato Regional Council can determine whether waters are safe for contact recreation and can track other water quality trends important for the ecology and appearance of the lake. The detection of any decrease in water quality can trigger discussion and possible action to remedy these changes.
Changing catchment land use can affect the amount of nutrients, sediment and ‘bad bugs’ (harmful bacteria and viruses) entering the lake. Waikato Regional Council monitors Lake Taupō’s water quality by measuring water clarity, chlorophyll a, oxygen, bacteria and nutrient levels. This information tells us about the health of the lake.
Lake Taupō is an oligotrophic lake. This means it has low concentrations of nutrients and so biological productivity is relatively low. Plants, such as algae, require nitrogen and phosphorus to grow. Low nutrient levels in the lake mean that the amount of microscopic algae the lake can support is low. This in turn means the water is particularly clear and blue, and dissolved oxygen levels are not seriously depleted (through decaying plant matter).
Lake Taupō’s water quality for ecological health is generally satisfactory to excellent. However, a few measurements of nitrogen (a plant nutrient) and chlorophyll a (an indicator of the total quantity of algae in a lake) have exceeded our very high standards for this lake.
Water quality for contact recreation is generally excellent. However, sites sampled near urban centres (Taupō foreshore, Te Moenga Bay and Acacia Bay) sometimes have raised bacterial levels.
You can also find out more about our river and catchment management programmes, which include soil conservation schemes designed to reduce sediment loads to the lake and protect the lake’s water quality.
Ministry for the Environment (external link) website - Water, Sustainable Land Management, and Managing Waterways on Farms.
Documents available from Waikato Regional Council
NIWA produces annual reports on the deep-water site monitoring results. A copy of each annual report is lodged with the Waikato Regional Council library. Of particular interest are:
Gibbs, M. 1995: Lake Taupō long-term monitoring programme. NIWA Consultancy Report EVW60203/1. NIWA, Hamilton. (First annual data report)
Verburg, P., Albert, A. 2016: Lake Taupō long-term monitoring programme 2014-2015. Waikato Regional Council technical report 2016/13. (Twenty-first annual data report)
This indicator will be updated annually (where the data is available).
Lakes Scientist/Programme Manager - Science and Strategy Directorate