Toitū Te Whenua LINZ is undertaking lakeweed control work on Lake Benmore to target Lagarosiphon major. The herbicide diquat is used to control weed. As per the label recommendation, the public are advised to stay out of the treatment areas and refrain from taking water from the lake for any purpose for 24 hours after treatment. You can find out more about this here: LINZ lakeweed control work information.
Operational Period
- Dates: Helicopter control will be undertaken starting, Wednesday 18 February 2026.
- Duration: 1–2 days of spraying
- Weather-dependent: Operations will proceed only in suitable weather conditions
- Signage: Key public access points and boat ramps will have signs 24 hours before and after spraying.
Targeted Treatment Sites
- The Neck
- Ahuriri Arm and Delta
- Sailors cutting
Details on Treatment:
- Method: Diquat in gel form will be used to treat aquatic weeds.
- Conditions: This work depends on suitable weed, water, and weather conditions, so the schedule may change without notice.
Recommended stand-down period:
- Avoid swimming, fishing, or taking water for irrigation or domestic supply for 24 hours following treatment.
To confirm actual treatment dates, please refer to LINZ lakeweed control work information.