Stormwater conference 2019 WSP Opus

24 April 2019 Chloe Brigden

Until recently, there has been no set tool or process that can objectively assess and evaluate the suitability of Gross Pollutant Traps (GPTs) in the field of stormwater management. Now, a new methodology devised by WSP Opus and Auckland Council can assess GPTs as a retrofit opportunity at sub-catchment levels. The methodology is currently being tested in Wairau Valley, Auckland - but could be rolled out across wider New Zealand.

Speaking at the Stormwater Conference on Thursday 2 May, Jackie Zhou, WSP Opus Senior Water Resource Engineer will present his whitepaper: Delivering Value for Money - Water Quality Improvements - Evaluating the Retrofit Proprietary Treatment Devices.

In his paper, Jackie references WSP Opus’ work for Auckland’s most polluted waterway, the  Omaru Creek, a small heavily urbanised stream system draining to Tamaki Estuary in Glen Innes.  The paper focuses on the evaluation and assessment of a variety of GPTs in Glen Innes Town Centre - aimed at rectifying the water quality in Omaru Creek by improving the removal process of gross pollutants and coarse sediments.  

The paper elaborates on the development of an approach to proactively determine the drainage sub-catchments; that can calculate contaminant loading and their transportation and estimate removal rates of the range of retrofit options to the existing stormwater network informed by literature review.

Why you attend Jackies presentation

  • This solution can be part of your treatment suite for improved water quality for existing urban areas.
  • You will find out how this methodology works with retrofit scenarios - beneficial if you don’t have much space to manoeuvre.  
  • The methodology is aligned to the 2017 amended National Policy Statement for Freshwater Management (NPSFM) - meeting the targets set in the current National Standard.
  • Presently, councils do not have anything of a similar standard in place. You can refer to this methodology as a first example for the assessment of GPTs in New Zealand. 
  • Can’t make the event? Be the first to read our findings and suggested actions.  Click here & request to download the official whitepaper. 


Request Whitepaper

 Don't miss out

Jackie, along with Eight- WSP Opus experts will be presenting papers at this year's Stormwater Conference. Attend Jackie’s presentation on Thursday 2 May at 1:30. View the Stormwater Conference full programme here.