As part of the No More Glyphosate NZ Council Herbicide Transparency Project, we asked councils across New Zealand about herbicide use in public spaces, the products being used, the policies governing their use, and whether those practices have been formally reviewed.
Kaipara District Council provided information relating to herbicide use within parks, reserves, gardens, and the roading network. The response identified herbicides used in parks and reserves, outlined application frequencies, described the standards governing herbicide use, and provided additional information from the council’s roading team regarding vegetation management within road corridors.
Quick Summary
| Topic | Response |
|---|---|
| Glyphosate-based herbicides used? | Yes |
| Other herbicides used? | Yes |
| Product information supplied? | Yes |
| Application locations identified? | Yes |
| Application frequency supplied? | Yes |
| Policy information supplied? | Yes |
| Roading herbicide practices supplied? | Yes |
| Formal review information supplied? | Partial |
| Supporting documents supplied? | No |
What We Learned
Kaipara District Council confirmed the use of Glyphosate 510, Haloxyflop 100, and Tordon Brushkiller within council-managed parks and reserves.
The council advised that glyphosate is used for edge spraying around trees, boundaries, hard surfaces, and garden weed control. Applications are generally undertaken four times per year, although treatment frequency varies depending on site requirements.
Additional information provided by the council’s roading team confirmed that herbicide application is also undertaken throughout the road corridor to maintain safety, visibility, drainage, and infrastructure performance. Roading-related spraying is typically carried out three times per year.
The council advised that staff applying agrichemicals are Growsafe accredited and work within Growsafe, HSNO, and Health and Safety at Work requirements.
Where Herbicides Are Used
According to the council’s response, herbicides are used in:
- Parks and reserves
- Street gardens
- Around trees and boundaries
- Hard surface edges
- Road edges
- Watertables and roadside drains
- Around signs, guardrails, culverts, and other roadside assets
- Kerb and channel edges
- Footpath edges
- Areas not maintained by adjacent landowners
The council noted that larger weeds within gardens are generally removed manually.
Products Identified
| Product | Active Ingredient |
|---|---|
| Glyphosate 510 | Glyphosate |
| Haloxyflop 100 | Haloxyfop-P-methyl |
| Tordon Brushkiller | Not specified by council |
Note: Some products may exist in multiple formulations. Where the council has not supplied active ingredients or product registration details, NMGNZ has chosen not to infer product composition.
The council’s roading team advised that it does not prescribe specific herbicide brands or products under the roading contract. Product selection is undertaken by the contractor in accordance with contract requirements and approved operating procedures.
Application Frequency
The council advised that glyphosate applications are generally planned on a frequency of approximately four treatments per year, depending on site requirements and weed growth.
Haloxyflop 100 is used as required for grass control within shrub gardens, while Tordon Brushkiller is applied as needed for the management of noxious weeds.
Within the roading network, herbicide spraying is carried out as a cyclic activity, typically three times per year, with timing determined through the annual works programme.
Policies, Standards and Oversight
Kaipara District Council advised that staff applying agrichemicals are Growsafe accredited and operate within:
- Growsafe requirements
- Hazardous Substances and New Organisms (HSNO) requirements
- Health and Safety at Work requirements
The council also referenced internal training guidelines.
For the roading network, herbicide use is governed by:
- The Road Maintenance and Renewals Contract (2024–2027)
- Resource Management Act requirements
- Regional environmental standards
- The contractor’s Contract Environmental Management Plan (CEMP)
- Relevant NZ Transport Agency specifications where applicable
According to the council, these frameworks are intended to ensure herbicide use is undertaken safely and with consideration for environmental effects.
The roading contract also requires contractors to select unscheduled or low-toxicity herbicides where practicable and appropriate for the vegetation being controlled.
Review and Safety Considerations
The council advised that its herbicide-use guidelines are reviewed as required, following incident investigations, and at least annually.
The roading team indicated that it could not locate information relating to a formal review of herbicide use in public spaces. However, operational practices are reviewed through annual work programming, contract performance monitoring, and environmental management processes.
Observations
Kaipara District Council provided a relatively detailed response and subsequently supplied additional information from its roading team to ensure the response covered both parks and reserve operations and road corridor vegetation management.
The response identified herbicides used within parks and reserves, described application frequencies, outlined the standards governing herbicide use, and provided information about how herbicide decisions are managed within the roading contract.
An interesting distinction emerged between council-managed parks and reserves, where specific herbicide products were identified, and the roading contract, where contractors are responsible for selecting products that meet contractual requirements relating to effectiveness, toxicity, and environmental impact.
The council advised that its herbicide-use guidelines are reviewed as required, following incident investigations, and at least annually. This is one of the more clearly defined review schedules identified so far through the Council Herbicide Transparency Project.
Why This Matters
Councils manage parks, reserves, gardens, roadsides, footpaths, and other public spaces used by residents every day.
Understanding what herbicides are being used, where they are applied, and how those decisions are managed helps improve transparency around public-space weed management.
The Council Herbicide Transparency Project aims to build a nationwide public record of how herbicides are managed across New Zealand’s local authorities, allowing residents to better understand practices in their own communities.
Information Request Details
| Item | Details |
|---|---|
| LGOIMA Reference | Not supplied |
| Request Submitted | 5 May 2026 |
| Initial Response Received | 3 June 2026 |
| Additional Information Received | 4 June 2026 |
Information current as supplied under LGOIMA on 3–4 June 2026.
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