Broadbrush push for spray consent

22:30, Nov 12 2012

Government agencies and the regional council want a regionwide consent to spray agrichemicals on Waikato waterways, sparking concern from iwi and some fruit growers.

This week an independent hearings committee will hear a resource consent application to aerially apply agrichemicals to waterways and Waikato's coastal marine area.

The application is a joint initiative between the Waikato Regional Council, the Conservation Department, Primary Industries Ministry, and Auckland-Waikato Fish and Game. Under the Biosecurity Act, the two government agencies and the council are responsible for controlling pest plants.

The parties hold 20 resource consents to discharge agrichemicals to waterways and the coastal marine area, targeting specific pest plants.

The application seeks to consolidate the "myriad of existing consents" held by the parties into a single regionwide consent as well as to ensure eradication activities are done in a timely manner.

In a staff report, regional council principal project leader Sheryl Roa said aquatic pest plants had the ability to recolonise quickly and current restrictions on spraying meant additional plant infestations outside defined areas could not be targeted immediately.


Targeted pest plants include alligator weed, manchurian wild rice, saltwater paspalum and emergent grasses.

The applicant proposes to use aerial spray via aircraft together with handheld operations from land and boat.

The report says weed control options such as hand weeding alone were not feasible, given some pest plants spread by breaking up and colonising new areas through viable fragments.

Seventeen submissions have been received on the application, including seven in opposition.

Several kiwifruit growers have opposed the application, concerned by the impact on their businesses.

The Tuwharetoa Maori Trust Board and the Maniapoto Maori Trust Board have also raised concerns, with the latter seeking ongoing research to ensure no adverse effects on non-target organisms.

Ms Roa said it was unlikely aerial spraying would contribute toward a decline in the water quality of the Waikato River or its tributaries, provided recommended consent conditions were complied with.