Client: Auckland Council
Thomas Services: Riparian (stream) restoration coordination, liaison with community organisations, managing physical works
Year: 2008 – 2014
The Wirihana Wetlands Project originated from the extensive work that Thomas Consultants have done with Project Twin Streams (PTS).
PTS is a Waitakere City Council/ Auckland Council initiative that began in 2003 with the aim to improve the health of streams in the Waitakere area and to reduce the amount of sediment and contaminants being washed downstream to the Waitemata Harbour.
Wirihana Wetland is located within the designated PTS area along Bishop Stream and near the boundary between Glen Eden and Titirangi. The wetland is close to the foothills of the Waitakere Ranges, but still in a highly urbanised environment surrounded by residential development. The main challenges of the site are the widespread weed coverage, and the impact of the impervious surfaces in the area that results in large influxes of water to the wetland during rain events.
Engagement with community and ‘buy in’ from residents on the boundaries of the wetland was especially important in delivering a good result for this project, in particular to prevent continuing incursions of weed populations from neighbouring properties. As a result of the work doen in the wetland restoration species are now becoming well established, creating a much-improved habitat and improved stormwater management in the upstream reach of the wetland. Engineering solutions are also being assessed for downstream stormwater management issues.
Delivery of the project was a collaborative process involving other professional teams from EcoMatters Environment Trust, Morphum Environmental Ltd and Wildlands Consultants.