3 Water Module
3.10 Lake Taupo Catchment
Environmental Quality Issues
Issue 1: Lake Taupo water quality decline - Effect on environmental values
Increases in nutrient discharges primarily from farming land uses but also wastewater disposal in the Lake Taupo Catchment have threatened the Lake’s water quality, resulting in:
- Increases in nitrogen in the surface waters of the Lake
- Increases in nitrate nitrogen in the bottom waters of the Lake
- More microscopic particles of nutrient dependant algae
- Increases in blue-green algae blooms
- Increases of algal slimes and other diatoms in shallow water
- Blooms of filamentous green algae along the Lake edge.
Expansion of settlements and associated sewage treatment facilities, and the resulting leaching of contaminants near the lakeshore, has had localised adverse effects on the shallow near-shore water environment including:
- Filamentous algae that coats rocks with a slippery surface
- Some nutrient dependent macrophytes, taking up clear swimming space close to the shore
- Periphyton that washes up on the shore, causing unpleasant odours
- Increased risk of adverse health effects when near-shore waters are used for recreation.
If nutrient discharges continue at the same level or increase, then the adverse effects will worsen and will result in a further decline in lake water quality.
Issue 2: Lake Taupo water quality decline - Effect on community values
The changes outlined in Issue 1 will be difficult to reverse, with the potential to significantly affect:
- Icon status of Lake Taupo and associated social and cultural value to local, regional and national communities
- Mana of Ngati Tuwharetoa as kaitiaki of the Lake
- Economic benefits to the local community from recreation and tourism activities
- Amenity and landscape values associated with the Lake
- Human health
- Natural character of the Lake
- The Lake’s trout fishery
- The Lake’s ecological health.
Social, cultural and economic effects
Issue 3: Social, cultural and economic effects associated with nitrogen management
Managing the discharges referred to in Issue 1 will have adverse social, cultural and economic effects on individuals and communities in the Lake Taupo Catchment, such as:
- Increased cost of compliance through new regulation and monitoring
- Nitrogen limits will reduce the range and types of land use options undertaken, particularly for pastoral, shrub land and forestry landowners
- Reduction in land values for some pastoral, forest and undeveloped land
- Reduction in farm income, to the point that farms may become unprofitable or not viable
- Preventing the opportunity to develop new or existing land uses where that development will result in a net increase of nitrogen to the lake
- Effects on the wider community and social and cultural structures such as declines in school rolls, rural services, and local businesses
- Limits on traditional Maori settlements of Papakainga or Marae buildings.