Spraying around Waterways: What you need to know
One of the most common questions we receive is: “What sprays can I use around my creek, pond, or water race?” Unfortunately there’s no single simple answer — but knowing the basics will help you make safe, effective choices.
The challenge with Waterways
Most products approved for use directly on water are designed for aquatic weeds - not for the gorse and brushweeds that typically plague lifestyle blocks and farms near waterways.
Products approved for Direct Water Application
| Active ingredient | Approved near water? | Conditions / notes |
|---|---|---|
| Triclopyr TEA | Yes (permit needed) | Approved as Garlon 3601 for wetlands |
| Imazapyr (isopropylamine) | Yes (permit needed) | Same council-held consents |
| Endothall (dipotassium) | Yes (permit needed) | Included in aquatic range |
| Diquat dibromide | Yes | Registered and widely used for submerged weeds |
| Glyphosate | Yes (permit needed) | Permitted in many regional plans |
Note: For gorse and many brush weeds, terrestrial products are often more effective than aquatic-approved products - and most of those terrestrial options are not legally approved for spraying on water. Councils sometimes issue permits for glyphosate use on water, making it the primary crossover option for both aquatic and many terrestrial weed control situations.
Key Safety Considerations
- Soil contamination - stay at least 5–10 metres from any water body.
- Spray drift – only spray on calm days; keep wind direction away from water.
Your Herbicide Options for Gorse Control
MSF600 (metsulfuron-methyl) - Most economical
Cheap and effective, but highly toxic to aquatic life, persists in soil (3–6 months), and slow-acting (6–8 months). Not our top pick near waterways.
GrassMate and Triclo - Premium priced
Fast-acting but expensive, ester-based (higher drift risk), and persistent in soil. Keep at least 10m from waterways.
Glyphosate 360 / Glyphosate 540 / Granny Herbicide
Mid-range cost and our preferred choice near waterways. Binds to soil (low leaching), breaks down faster, and lower drift potential. Always check local council rules and product label.
The Wetter Dilemma
Most gorse treatments require a wetter. Our standard SuperWetter is very effective, but can increase leaching. For safer use near waterways, choose BioWet, or even blend BioWet + SuperWetter for balance.
The Safest Approach: Cut and Treat
- Cut gorse at ground level.
- Treat stumps with Glyphosate 540 (130ml/L) + SuperWetter (10ml/L).
- Or use Cut’n’Paste Glimax Professional for even better results.
Before you spray
Always check your regional council’s rules. Read product labels carefully, and when in doubt, call us to discuss your specific situation. For full product details and pricing, visit the Rainbow & Brown site.
Need help choosing the right product?
Call us toll-free on (0508) 299 299 or browse our herbicide range.
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