An urban Auckland waterway said to be "in pretty bad nick" is to be the focus of a massive winter riparian planting project involving hundreds of volunteers.
More than 12,000 native plants and trees are to be planted between now and August along a stretch of the 63km-long Papakura Stream, which has been rated as among the worst 25 per cent of all urban sites in New Zealand for levels of E.coli (bacteria) by Land Air Water Aotearoa (LAWA).
The Papakura Stream Restoration Project is being led by Conservation Volunteers NZ (CVNZ) in partnership with the Franklin, Papakura and Manurewa local boards, landowners (including dairy farmers, a beef farmer and an equestrian centre) and local companies.
CVNZ's strategic partnership manager Siobhan O'Grady says the catchment around the stream was once covered in lush forests of kauri, taraire, tawa along its upper reaches and kahikatea swamp forests in the lower reaches. But over many decades its habitat has deteriorated due to the impact of agriculture, industry and urban development.
"This has led to a massive reduction in forest cover and water quality and this in turn reduces habitat for native species and increases the sediment, pollution and nutrients entering the stream and making their way to the precious Manukau Harbour.
"To be honest, it's in pretty bad nick," O'Grady says. "High levels of E.coli have been recorded and we find all kinds of waste - lots of kids bikes, shopping trolleys, bottles and items like pie wrappers and chip packets - submerged or floating in the water."
O'Grady says the area is also home to several species of endangered wildlife such as the kaka, longfin eel and long-tailed bats. "Something really has to happen as quickly as possible while we still have time to protect these species and there is no time like the present."
She says the aim is to restore and protect at least a 5km stretch of the stream in the next five years through both an extensive planting programme and fencing with recycled plastic fence posts around the stream and fragile wetland areas. Already 1000 plants have been put in along its banks in work carried out when the project launched in May.
Between now and August O'Grady says a further 11,000 natives will be planted including grasses and tree varieties such as kanuka, kahikatea, manuka and cabbage trees. Up to a 1km area around wetlands will be fenced off and many litter clean-ups undertaken.
"All up, we'll have about 500 volunteers helping with planting over the winter including at least two school groups," O'Grady says.
The stream runs from its headwaters in Brookby and enters the Manukau Harbour at the Pahurehure inlet. Its catchment covers an area of just over 4000 hectares.
An Auckland Council report, River Water Quality in Tamaki Makaura/Auckland released in February, classed water in the lower stream as poor and marginal in its upper reaches. It also established that the upper regions of the stream "occasionally exceeded the total oxidised nitrogen guideline."
The stream was one of 36 city waterways monitored for water quality between 2017 and 2019. More than 60 per cent were assessed as being marginal to poor with less than 14 per cent rating good to excellent (most of these are in native forest areas).
And in data published on LAWA website, the stream was rated among the worst 25 per cent of all urban sites for levels of E.coli and the worst 50 per cent for levels of total nitrogen in the water.
O'Grady says the project aims to educate and encourage landowners to restore their riparian margins, the community on how to protect waterways and to identify public spaces such as council reserves for planting events.
One of the landowners involved is Andrew Hogan who runs a herd of 40 beef cattle on a 60-acre lifestyle block at Brookby along the upper reaches of the stream. He and wife Lyndelle took over the property about four years ago and were told about the project after clearing a lot of dead and rotting poplar and gum trees near the water.
"I spent about $30,000 of my own money doing this," says Hogan. "A lot of trees had fallen into the middle of the stream and I thought someone could get killed if we didn't do something. I like things nice and I decided unless I re-planted, the ground would be taken over by weeds."
He initially started planting himself but is now part of the restoration project. So far around 1000 native trees and plants have gone in on his land (the stream runs for about a kilometre through the middle of his property) and there are plans to plant another 3000 this year.
"We are very happy to be part of this project," he says. "It can only be good for the wildlife and I'm sure in a couple of years we'll start to see native birds coming back."
Along with landowners, the project is also aiming to encourage community groups, schools and businesses to get involved in helping with tree planting, pest plant control, plant maintenance and litter clean-ups.
For more information go to: conservationvolunteers.co.nz