Property owners and users of Lake Wanaka, including for recreation, are advised that the herbicide diquat will be applied in gel form to control lake weed (Lagarosiphon) at the following sites in Lake Wanaka:
- Glendhu Southern End
- Glendhu Bay
- Glendhu Bluff
- Paddock Bay
- Parkins Bay
- Stevensons Arm
- Stevensons Island
- Mt Burke to Quartz Creek
- Bishops Bay
The spray operations may involve the discharge of harmless tracer dye during and/or prior to the spray operations. The dye is used to mimic the discharge of herbicides in order to obtain information about the dilution and dispersion characteristics after it has been sprayed on the target weeds. The key adverse effect of the use of the dye will be the temporary visual impact of the dye plume in the water. The dye is harmless, there will be no adverse effects on the aquatic ecology of the water body, and the dye will continue to be diluted until it is no longer visible.
The work is scheduled to begin from Monday 21 May 2012 and may continue intermittently to Friday 8 June 2012, as weather and water conditions permit. Treatment will not take place during weekends or on public holidays.
As a precautionary measure only, Land Information New Zealand advises users not to take water from the Lake Wanaka to consume or for irrigation purposes from the vicinity of the treatment area, until 24 hours after treatment has been completed.
A helicopter and boat will be used to apply the herbicide when conditions are suitable.
Weed control on Lake Wanaka is overseen by the Wanaka Lagarosiphon Management Committee which includes representatives from Queenstown Lakes District Council, the Guardians of Lake Wanaka, Otago Regional Council, Land Information New Zealand and the Department of Conservation.
View Land Information New Zealand's full annual control works programme.
Further information is also available from Boffa Miskell Ltd during office hours on 0800 638 943, by writing to PO Box 110, Christchurch, or emailing firstname.lastname@example.org