The Queenstown Lakes District Council applied earlier this month for a five-year consent to undertake work within the riverbed to create a 200m to 300m diversion channel to allow discharge of treated effluent from the Shotover Wastewater Treatment Plant into an actively flowing channel of the internationally known braided river.
The QLDC has not yet applied for the emergency work now under way — the council is discharging treated wastewater into the river to reduce the risk of bird strike at nearby Queenstown Airport after birds gathered at the treatment plant’s failing disposal fields.
The Otago Regional Council has yet to say whether the application for the enabling works will be publicly notified, but on its website the ORC said it was following a step-by-step process to ensure its decision on whether to notify the application was consistent, fair, and based on environmental effects and planning rules.
The QLDC did not ask for its application for the enabling works to be publicly notified and said the environmental effects of creating the diversion channel were considered less than minor.
The district council has been releasing 12,000cu m of treated wastewater into the river per day since March 31.
Although the practice was used up to 2019, the emergency works have been controversial.
The QLDC’s application said since the discharge channel was last used more than five years ago the Shotover River had naturally shifted at the location of the outfall, and the main braid had moved more towards the east.
Works were required now to maintain a flowing braid past the outfall to improve the mixing of freshwater and effluent, the application said.
However, the application said refuelling would take place at least 20m from flowing water; machinery would be washed before entering the riverbed; "erosion and sediment control measures" would prevent uncontrolled contaminated runoff from entering the river — and "as much of the diversion works as possible" would be done in the dry, to minimise time spent working in actively flowing water.
"This will involve excavating most of the diversion channel and recontouring the surrounding area prior to connecting the final segment of the diversion channel to the wetted river channel."
The Otago Daily Times asked the QLDC yesterday if it would ask for its retrospective application for the emergency works at the Shotover treatment plant to be publicly notified, but no answer was provided.
At a council workshop yesterday, staff said the application was expected to be filed by the end of tomorrow.
