Winton and Manapouri residents are in line for upgrades to their wastewater treatment systems, following the expiry of existing consents in 2023 and 2024 respectively.

Discharging treated wastewater to the current water sources is no longer a viable option due to recent regulatory changes, forcing options for only land based discharge to be considered. 

The Southland District Council (SDC) has contracted GHD Limited and Harrison Grierson Limited to identify viable options for wastewater treatment systems for both towns. 

However in the meantime SDC will apply for an extension or amendment to the existing discharge consents to allow time for investigations to be undertaken and decisions on the best options to be made.

From a shortlist of ten options for Winton's wastewater, one is considered the most viable according to a SDC statement.

This would be to construct a treatment facility at the existing Winton ponds and pump the treated wastewater for disposal to land near Winton.

This project is estimated to cost between $27 million and $66 million.

Five wastewater options, with projected costs of between $6.1 million and $10 million, have also been identified for Manapouri.

These include;

• Option 1: treatment plant at Manapouri – new pipeline to Kepler
• Option 2: treatment plant at Kepler – new pipeline from Manapouri pump station
• Option 3: pumped to Te Anau wastewater treatment plant
• Option 4: treated effluent from Manapouri plant pumped to Te Anau
• Option 5: treated effluent from Manapouri wastewater treatment plant pumped to new plant at Kepler.  

Options 1, 2 and 5 appear to be preferred with more investigation on each being recommended, the SDC statement said. Each of these options would involve treatment facilities located at either the Manapouri ponds site or the Kepler sub-surface drip irrigation (SDI) disposal fields.

SDC said two further options based on pumping Manapouri wastewater to Te Anau have been abandoned due to cost. 

The final solution would need to meet criteria related to treatment quality matching or exceeding Te Anau’s wastewater, ability to fit within the available land, noise limits, odour control and value for money, the statement said.

SDC will be holding a community drop-in session for residents in both Winton (Memorial Hall, 2-6pm, 25 July) and Manapouri (Te Anau Manapouri Airport, 2-6pm, 15 July).