Carterton District Council infrastructure, planning and regulatory manager Dave Gittings on site at Daleton Farm. PHOTO/GIANINA SCHWANECKE
GIANINA SCHWANECKE
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Motorists driving along State Highway 2 north from Greytown will have noticed an increasingly large hole south of Carterton.
It’s not a new subdivision, but the next stage in construction of Carterton District Council’s new wastewater treatment plant on Daleton Farm.
Planning began in 2014 as part of the council’s long-term plan to improve the treatment of urban wastewater in a sustainable way.
The new treatment plant will allow the council to irrigate most of its wastewater on to the surrounding 40 hectares of farmland, limiting the amount of wastewater and nutrients discharged into the Mangatarere Stream.
With a budget of $6 million, it’s the council’s second biggest spending project after construction of the Carterton Events Centre in 2012, which cost close to $9 million.
The project is expected to take about five years to complete.
Work was delayed after the discovery of native mudfish in November which prompted the council to organise a relocation project – but less than 200 of the original 900 fish survived the move.
Stage two began earlier this year with construction of the three 200,000m3 storage reservoirs.
With a footprint of about eight hectares, the new reservoirs are certainly unmissable for motorists on SH2.
Council infrastructure, planning and regulatory manager Dave Gittings said the site was chosen because of the “natural banks” in the land, which allowed the council to cut down construction costs.
Construction work was contracted out to Central Hawkes Bay [CHB] Earthmovers Ltd, of Waipukurau, with work expected to be completed in the coming months.
The reservoirs will store treated wastewater effluent allowing control of discharge levels when it is too wet to irrigate to land or when the stream is in high flow.
The council’s consent allows a maximum of up to 10 million litres a day to be discharged to land, with the existing pivot irrigator operating about 30 days each year over 20 hectares of land.
The consent also allows discharges to Mangatarere Stream when the flow is three times above the median rate, and occasionally of discharge to the stream during flows below three times the median.
Gittings said annual discharges would vary due to weather conditions and population.
Over the next few months, he said, those passing by the site would start to see the framing of the three storage ponds develop more clearly.
“Reservoir construction started in January and is expected to be completed early next year. The installation of associated pipework and a second [irrigation] pivot is planned over the next two years.”
He said progress on the reservoir’s construction would depend on the weather.
“The dry has been really good.”
Next year work will begin redirecting water from an unnamed tributary above the original wetlands to lower reaches of the Mangatarere Stream when it is at high flow.
Stage 2 facts:
- 3 kilometres of pipes to be installed
- 5 kilometres of strip drains to be installed
- $6 million spending budget
- 200,000 tonnes of earth moved
So why not put in bio gas plant like all the other forward thinking countries and reduce outflows into the mangatarere