TetraTrap
At a glance
Protecting Auckland’s beaches, harbours, and waterways is vital for maintaining a world-class coastal city. In partnership with Auckland Transport, GHD has developed the TetraTrap, a simple yet innovative device that reduces contaminants entering Auckland’s waterways.
The challenge
A significant percentage of the water that ends up in Auckland’s marine environment comes from the roads, either through the stormwater system, or via lakes and streams. But without filtering or treatment, this often carries rubbish and pollutants with it, which end up in our waterways.
Our response
To combat this, TetraTraps are retrofitted into roadside stormwater catch pits, providing an at-source barrier that collects gross pollutants and contaminants like litter, sediment, and heavy metals.
Made from stainless steel and with no moving parts, TetraTraps are low maintenance, cost effective, and completely recyclable. They are quick and easy to install, and can last up to 30 years. GHD has created a range of designs, to fit different catchpit configurations.
In collaboration with Auckland Transport and Auckland Council, a prioritisation and implementation programme is improving Auckland’s road stormwater quality. This considers priority areas for treatment, including public transport facilities, high volume roads, town centres, and commercial and industrial areas surrounded by sensitive environments.
The impact
Over 3,500 TetraTraps have been installed, and have already collected tonnes of refuse that would otherwise end up in Auckland’s waterways. Throughout 2020 and beyond, we have proposed to install more in priority areas, including Auckland Viaduct Basin and Wynyard Quarter.
Creating healthier waterways for future generations, TetraTraps are helping Auckland live up to its reputation of one of the world’s most liveable cities.