Wetland for treatment plant

18:58, Feb 27 2014
PLANTING FOR CLEANER WATER: A contractor helps out with the development of the 10 hectare wetland at the site of the Aorangi Rd oxidation ponds.

A massive wetland is being created as Timaru's wastewater treatment plant upgrade nears completion.

More than 96,000 plants, mostly native reeds, will be laid out over a 10 hectare section at the Aorangi Rd site over the next two weeks.

Timaru District Council district services manager Ashley Harper said North Island-based KPN Nurseries began planting the site on Monday.

"It's a massive project, but it's absolutely necessary for the wastewater treatment project. It helps act as the final stage of cleaning, as well as creating a habitat for birds and insects," Mr Harper said.

He said the job would cost about $400,000. KPN was also responsible for maintaining the plants over the next year.

It was expected the last of the planting would be completed next week. KPN had about six staff on the job. "They're going through it really quickly," Mr Harper said.


The wetlands project is a key component of the $17 million upgrade, on which work began in April last year. Mr Harper expected construction to be finished within the next two months, while it would take another six to eight months to become operational.

To the north side of Aorangi Rd, 30ha of land are being sculpted into primary oxidation ponds and 8ha into maturation ponds.

"When you've got a project as big as this, everything has to be ticked off," Mr Harper said. "We've been lucky this summer with the weather. We had delays last year (due to high winds and flooding), but in the last couple of months, we've scarcely lost a day to rain."

Most of the clay and other material was sourced from near the site, but some came from a quarry in Rolling Ridges Rd.

Over the last decade, the council has been working through its wastewater management strategy, which has included a near-total overhaul of some systems.

Mr Harper estimated the total cost of all the strategy's projects was over $50m. This has included a new main sewer line from the Timaru Railway Station through three tunnels and out to Aorangi Rd, while piping was installed from Geraldine, Temuka and Pleasant Point to carry effluent to the Timaru treatment station.

The Timaru Herald