Notice of Weed Spraying in Lake Dunstan

8 June 2010

Property owners and users of Lake Dunstan, 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 Dunstan.

  • Bannockburn Inlet
  • Bendigo Boat Ramp and Approaches
  • Champagne Gully Ramp and Ski Lane
  • Pisa Moorings – Inlets, Public Boat Ramp and Shoreline
  • Cromwell Swimming Beach
  • Jacksons
  • Lowburn Inlet
  • McNultys Inlet and Boat Ramp
  • Northburn Ski Lane
  • Annan Inlet
  • Smiths Way
  • Old Cromwell Town and Boat Ramps (note this site may also be controlled by suction dredging).

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 16 November 2009 and may continue intermittently to Friday 18 December 2009, 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 Lake Dunstan to consume or for irrigation purposes from the vicinity of the treatment area, until 24 hours after treatment has been completed.

Notices will be placed at www.linz.govt.nz 24 hours prior to the planned spray dates. Warning signs will be placed at authorised public boat ramps during treatment and will be removed 24 hours after treatment.

A helicopter will be used to apply the herbicide over a 4 to 6 hour period when conditions are suitable.

A copy of Land Information New Zealand’s full annual control works programme is available. Further information is available from Boffa Miskell Ltd during office hours on 0800 638 943, by writing to PO Box 91250, Auckland 1142, or emailing tim.mckenzie@boffamiskell.co.nz

Media enquiries: Brad Young, Land Information New Zealand, phone +64 4 460 0147, mobile +64 27 277 1267, email
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