Assessing the performance of stormwater treatment

Stormwater treatment is becoming increasingly important as we learn more about the adverse effects of diffuse pollution on our receiving environments.

Stormwater treatment is becoming increasingly important as we learn more about the adverse effects of diffuse pollution on our receiving environments.

There is an array of different treatment devices available to manage peak flows and reduce contaminants. But how do we know if these devices work? Can we predict their effect on water quantity and quality? What happens if we change their design? And what will happen with changes in storm intensity anticipated due to climate change?

NIWA's scientists can assist in answering these questions and more through desktop and field studies. We have experience in designing and carrying out monitoring programmes to measure the performance of treatment systems, and in developing models for stormwater treatment devices to understand the processes and predict their operation.

Examples of NIWA's experience in assessing and modelling stormwater treatment include the following projects:

  • Assessing the performance of ponds and grass swales in removing contaminants from stormwater.

Read the full report - Research Report 395: Enhancing the control of contaminants from New Zealand's roads: results of a road runoff sampling programme (PDF 2.7 MB)

  • Investigating the performance of proprietary filter-based stormwater treatment devices installed in the field. 
  • Investigating the ability of ponds to reduce sediment from earthworks, with and without flocculation chemicals. 
  • Measuring the performance of a raingarden designed to reduce peak flows and improve stormwater quality. 
  • Developing floating wetland systems for stormwater ponds to provide additional water quality treatment (Click here for a link to the full report). 

Read the full report - Floating Vegetated Islands for Stormwater Treatment: Removal of Copper, Zinc and Fine Particulates (PDF 1.3 MB)

For further information on our services in stormwater treatment please contact [email protected]

Pond and swale performance assessment. Credit: NIWA
Performance of proprietary filter-based stormwater treatment devices investigation. Credit: NIWA
Pond reduction of earthworks sediment investigation. Credit: NIWA
Raingarden performance assessment. Credit: NIWA
Wetland systems for stormwater ponds development. Credit: NIWA