Improvements are in the pipeline for the way treated wastewater is managed at the Banks Peninsula settlement of Duvauchelle.
The treated wastewater is currently discharged to Akaroa Harbour. The Christchurch City Council’s consent to do this expires in 2023. It is a condition of that consent that the Council explores all feasible alternatives to sending treated wastewater to the harbour – a practice that is deeply offensive to Māori.
The Council is now seeking community feedback on two options, both of which involve using treated wastewater to irrigate the Akaroa Golf Course at Duvauchelle.
The golf course land is owned by the Council and leased to the Akaroa Golf Club. It is the only land area at Duvauchelle large enough to receive the treated wastewater.
The Council’s Head of Three Waters, Helen Beaumont, says finding a land-based alternative was crucial, and staff have been working with the Akaroa Golf Club, the Duvauchelle Working Party and Ngāi Tahu to identify feasible options for about 12 years.
“It’s been a long process,” Ms Beaumont says. “We identified and investigated 12 feasible options and gradually whittled those down to two that were acceptable to Council, the golf club, the working party and Ngāi Tahu.”
Upgrading the harbour outfall was not short-listed as it would be highly unlikely to get resource consent if there are viable land-based alternatives.
The first option the Council is seeking feedback on is using treated wastewater from Duvauchelle to spray irrigate the golf course tees, greens and fairways in dry weather (summer) and to drip irrigate the planted course margins and uphill areas of trees on the golf course property in wet weather (winter).
This is the option preferred by staff as it is a true example of beneficial reuse of treated wastewater.
The wastewater would be treated to the standard required for use as irrigation to a golf course, which would require a major upgrade of the treatment plant and new pipes and drainage at the golf course. The estimated capital cost is $13.1 million.
The second option is to drip irrigate the planted areas, course margins and uphill areas of trees on the golf course property year-round. However, this would not use all the treated wastewater so another property would need to be bought or leased to irrigate native trees.
The wastewater would not need to be treated to as high a standard as in the other option so the plant upgrade would be minor and there would be less drainage and pipe work needed at the golf course. The estimated capital cost for this option is $8.2 million.
More information about the options is on the Council’s website at ccc.govt.nz/Duvauchelle. Consultation is open until 5pm on Tuesday 7 June 2022.