Auckland Council’s Wai Care team accepted the ‘Most Improved’ award at last night’s NZ River Awards, for its work to improve water quality in the Puhinui Stream.
The awards are run by the NZ Rivers Trust and the Morgan Foundation to recognise long-term improvement in waterways around the country.
An incredible transformation
Just six years ago, the former Auckland Regional Council considered Manukau’s 12km Puhinui Stream to be the dirtiest of all 31 streams that were monitored. It was also rated in the bottom 25 per cent of rivers for E. coli, ammoniacal nitrogen and total phosphorus levels.
Now, the Puhinui is the most improved of about 300 rivers monitored by regional councils in New Zealand. This is a huge achievement given the challenges of improving a river that is highly modified as it travels through urban and light industrial areas.
Auckland Council’s General manager for Environmental Services, Gael Ogilvie, says, “We are delighted to accept the NZ River Awards on behalf of all the people who have worked together to produce such an outstanding improvement.
"Huge thanks to our Wai Care team, Manukau Beautification Trust, The Botanic Gardens, and all the amazing community members, including local schools and Rotary members, who have given their time and energy to the clean-up.”
Well-coordinated plan of action
A well-coordinated plan over the past 15 years has seen some major changes being made to restore the Puhinui Stream.
This includes Auckland Council retiring 20ha of land from grazing to plant the riverbanks and wetlands, community groups eco-sourcing plants to grow alongside the river, and the Auckland Botanic Gardens introducing a sustainable water trail to remove sediment and heavy metals from the water, and reduce nitrates and phosphorus.
One of the biggest commitments has come from The Gardens School. They have been growing plants on the school grounds from seeds, then planting along the stream bank every year, keeping the water cool and clear.
The biggest thing that makes the difference to water quality is this kind of planting. More than 25,000 natives have been raised and planted to date.
In an impressive show of community spirit, the Manukau Beautification Trust held the largest clean-up in New Zealand history last year, focusing on the Puhinui. More than 1900 volunteers cleaned out an incredible 13 tonnes of rubbish, including 200 trolleys and 300 tyres.
About the Puhinui stream
The Puhinui stream runs 12km through Tōtara Park and the Auckland Botanic Gardens, through Manukau City urban and light industrial zones, and ends up in the Manukau Harbour, not far from the airport.
As a measure of assessing water health, the NZ River Awards uses the macro-invertebrate community index (MCI). This counts the number and type of macro-invertebrates present in the water, and includes aquatic animals such as insects, freshwater crayfish, snails and worms.
Their presence (or lack of) is a strong indicator of the health of a river.
If you’d like to get involved in improving waterways in your own area, contact Auckland Council’s Wai Care team.