The Kaipara: big research for a big place
Fine sediment runoff from deforested and disturbed catchments is recognised by management agencies as being the principal threat to New Zealand's estuarine ecosystems.
Rivers
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Catchment modelling of sediment loads to estuaries
Estuary sedimentation is a continual natural process. Land slope, land use, soil type and rainfall all have significant impacts, and form a complex spatial pattern of sediment generation.
Multiple effects of fine suspended sediment from the Kaipara Harbour catchment
Our research aims to link measurements of fine sediment and water quality to advance our understanding of the multiple environmental effects of fine sediment.
NIWA initiates new information system for urban stormwater quality
Urban runoff is a major source of contamination for streams and estuaries, and can result in the accumulation of metal and organic contaminants in sensitive environments.
Tracking water age in hydrological models
Building a hydrological model
Hydrological models enable us to predict river flows and floods,
River flows - April to June 2012
River flows - April to June 2012
The three month picture (on the right) shows the extreme dryness across most of the country, and the after effect of a wet April over East Cape and Hawkes Bay.
Water quality maps and information, April to June 2012
River temperatures April to June
Autumn river water temperatures were mostly in the range 8 to 16oC and tended to be slightly higher in the north and at lower altitude.
River flows - January to March 2012
Observed flow Jan-Mar 2012:
River flows were far above normal in most of the North Island and in Central Otago, and far below normal on the West Coast of the South Island.
Water quality maps and information, January to March 2012
River Temperatures, January to March
Clear as mud? Predicting water clarity and light penetration in estuaries
Fine sediment loads delivered to estuaries by rivers are higher today than prior to catchment deforestation due to increased soil erosion. The effects on water clarity, which then impact sensitive estuarine ecosystems, are significant.
Novel tool for weed control
NIWA research on Mycoleptodiscus terrestris (Mt) shows the fungus could potentially be used as an environmentally safe "natural" herbicide.
Water Quality maps and information, October to December 2011
River Temperatures (OND)
Understanding contaminant loads in farm runoff
NIWA and AgResearch are working together to develop and test practical approaches for farmers to meet environmental targets.
Street sweeping - A stormwater best management practice
A study on the benefits of street sweeping for reducing stormwater contaminant loads to streams has been completed for Nelson City Council (NCC). The study found that properly designed street-sweeping programmes can reduce contaminant loads in catchments by approximately 30 per cent.
Emerging contaminants – a trendy catch phrase or an issue worth pursuing in New Zealand aquatic environments?
A recent study by NIWA has identified levels of some emerging contaminants around the Auckland marine environment that are similar to those measured in other industrialised countries.
What are emerging contaminants?
Constructed Wetlands for household wastewater
On-site disposal of poorly treated household wastewater can be a significant source of pollution in ground and surface water.
Water quality maps and information, April to June 2011
River Temperatures
Water quality maps and information, July to September 2011
Our latest water quality data from around the country, showing results from July to September 2011.
Retrospective river flows, July to September 2011
What we predicted for July 2011 to September 2011
River flows are likely to be normal in the North Island and north of the South Island, and normal or below normal in the rest of the South Island.
What actually happened during July 2011 to September 2011
River flows were normal to below normal for most of the country, with some above normal river flows in the eastern North Island, eastern Southland and coastal Otago.
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Coastal and Estuarine Physical Processes Scientist
