Freshwater

NIWA is involved in research and consultation' aimed at improving the health of our freshwater systems.

A project funded by West Coast Regional Council has increased our knowledge of the role of phosphorus in determining water quality in Lake Brunner.

Many New Zealand lakes are suffering from nutrient enrichment, causing potentially toxic blooms of blue-green algae. NIWA is testing a range of methods to manage phosphorus release from lake sediments – including sediment-capping agents.

Gathering, eating and sharing wild kai (food) has always been a very important part of Māori culture and wellbeing - this research project aimed to characterise the risks associated with consuming kai collected from rivers, lakes and coastlines.

This project involves the development of a computer-based framework for freshwater models. The framework will be tested to proof-of-concept stage.

NIWA has produced revised safe levels of dissolved oxygen for fish, which will help inform future environmental planning and resource consents and help to keep New Zealand rivers full of healthy fish.

Streams play a key role in the ecosystems of New Zealand’s unique landscape. They feed and link together freshwater sources, maintain good water quality and support habitats that sustain our biodiversity.

The giant kōkopu is a native whitebait species considered rare and vulnerable. NIWA is working with Mahurangi Technical Institute and environmental consultancy Boffa Miskell to test the feasibility of reintroducing giant kōkopu to Nukumea Stream, north of Auckland.

This project was undertaken for Auckland Regional Council to identify significant sources of contaminants in the central Waitemata and southeastern Manukau Harbours.

This project will demonstrate the commercial feasibility of producing bio-oil by the conversion of algae biomass that has been grown in wastewater treatment facilities. In particular we aim to maximise algae production in High Rate Algal Ponds (HRAP) by adding carbon dioxide, and demonstrate energy efficient conversion of algal biomass to bio-oil.

Estuaries are highly valuable systems that provide enormous economic and cultural benefits to all kinds of people. However, expanding human populations and urban development around estuaries is increasing contaminant loads, with metals and polycyclic aromatic hydrocarbons (PAHs) accumulating in sediments.

Farmers rely on irrigation, but water is a limited resource and little is know about how to manage it best. NIWA has developed a hydrology and soil science model to show how much to water, and when, to get the best results.