Eutrophication Explorer

A web application tool to explore monitoring data and model predictions related to stream and estuary eutrophication

A web application tool to explore monitoring data and model predictions related to stream and estuary eutrophication

The Problem

Eutrophication is an increase in the nutrients in a water body, which can increase growth of primary producers (e.g., aquatic plants, stream periphyton, estuarine algae) to nuisance levels and degrade water quality (e.g. reduced oxygen levels and visual clarity).

Eutrophication is a widespread problem in freshwater bodies in New Zealand and it impacts values such as recreation, the life-supporting capacity of waterways, and food-gathering. Regional Councils are obliged to monitor and manage eutrophication in catchments and estuarine environments under the National Policy Statement for Freshwater Management (NPS-FM) which came into effect in 2020.

NIWA research aims to enhance robust and precise limit setting, thereby leading to improved economic, cultural and environmental outcomes. The creation of Eutrophication Explorer is part of NIWA’s initiative to address multiple eutrophication issues.

The Solution

The Eutrophication Explorer web-based tool was developed to help identify eutrophication drivers and risks across a catchment and estuary. It is anticipated that this tool will enable communities and regional councils to explore where the eutrophication risks are in a catchment, what is driving the risks, and potential solutions.

The Eutrophication tool can:

  • Map predictions of eutrophication drivers across streams, lakes and estuaries in a catchment e.g., nutrient concentrations, flows, shade, etc.
  • Include historical observations (e.g. nutrients, macrophytes, periphyton, estuary water quality) for comparison with the models.
  • Use built-in models of risk for macrophytes, periphyton and Estuary Trophic Index.
  • Look downstream for the location most affected by eutrophication.
  • Undertake simple scenario testing, i.e., change inputs and estimate change in risk.

Testing of Eutrophication Explorer is currently underway with Environment Southland and the demonstration tool can be viewed here  -

Here is a video of the Eutrophication Explorer demonstration tool in action:

Eutrophication Explorer tool demonstration