Freshwater quality

A high proportion of New Zealand’s native freshwater fish fauna need to migrate to and from the sea.

Nutrients in waterways are essential for the growth of algae and aquatic plants but too much can destroy an ecosystem.

The condition of many NZ lakes is under threat from land-use changes and the invasion of alien aquatic plants.

NIWA is doing a nationwide study to discover what makes the best riparian projects. Help us give you the knowledge to make the best riparian management decisions possible by taking our 5 minute survey.

NIWA provides technical background information on "Clean Water" swimmability proposals.

New Zealand’s freshwater and estuarine resources provide significant cultural, economic, social, and environmental benefits. Competition for the use of these resources is intensifying, and many rivers, lakes and estuaries are now degraded.

The tools available for restoring kōura to lakes and streams depend on what is causing kōura to decline.

First, determine if kōura should be present in your stream.

Identifying the factors causing kōura numbers to decline will allow you to determine which restoration tools you need to employ.

Habitat degradation and the introduction of exotic plant and fish species have adversely affected kōura populations throughout New Zealand. However, there are a number of measures that we can use to restore kōura populations in lakes, rivers and streams.