What is a weed boom?
A Weed Boom is used to intercept free floating aquatic vegetation and surface blooms in still or slow moving waters, and is commonly applied to invasive floating weeds such as water hyacinth, salvinia, water lettuce and blue-green algae.
Below are the invasive plants and blooms that weed boom can contain.
1) Free floating aquatic weeds (best fit)
Free floating aquatic weeds float at the surface, drift with wind and flow, build up at outlets, narrow points and windward shorelines, and can spread quickly once they enter connected waterways.
COMMON EXAMPLES:
Salvinia (Salvinia molesta)
Salvinia is an aquatic free floating fern and is listed as a Weed of National Significance (Weeds Australia 2026a). Because it floats, it is well suited to interception and collection using a weed boom.
Source: Lucid Key Server (Identic Pty Ltd), “Salvinia molesta”. Photo: Sheldon Navie.
Water hyacinth (Pontederia crassipes, formerly Eichhornia crassipes)
Queensland guidance describes water hyacinth as a major invasive plant of creeks, rivers and dams in Australia (Business Queensland 2026a). Floating infestations are commonly pushed by wind and flow into narrow points, which makes interception valuable near outlets, culverts and infrastructure.
Source: Queensland Government (Business Queensland), “Water hyacinth”. © Queensland Government.
Water lettuce (Pistia stratiotes)
Water lettuce is described as a free-floating weed introduced to Australia for aquariums and ponds that has spread into waterways, and it is a restricted invasive plant under Queensland legislation (Sunwater 2025; Business Queensland 2026b). Its free-floating nature makes it a strong fit for boom interception.
Source: Queensland Government (Business Queensland), “Water lettuce”. © Queensland Government.
2) Floating fragments of certain invasive weeds
Some invasive weeds spread when pieces break off and float downstream. A weed boom can help intercept those fragments.
Alligator weed (Alternanthera philoxeroides) NSW guidance notes that alligator weed spreads naturally in water when stem or root fragments float downstream (NSW Department of Primary Industries 2026a). Where fragments are drifting at the surface, a weed boom can reduce downstream spread risk by creating a containment line.
Source: Queensland Government (Business Queensland), “Alligator weed infestation”. © Queensland Government.
3) Visible surface accumulations during blue green algae events
Blue green algae are cyanobacteria, which are true bacteria, although they are often called blue green algae because they resemble algae and can photosynthesise (NHMRC 2022). Under bloom conditions they can form visible surface accumulations that shift with wind and surface conditions.
Source: Wikimedia Commons. Photo: Mary Cousins (Mmelugin). Licensed under CC BY-SA 3.0.
A weed boom may help by:
- keeping visible surface accumulations from drifting into offtakes, access points, and downstream waterways
- supporting operational management by defining a containment line
A weed boom cannot:
- remove dissolved toxins
- replace public health guidance, monitoring programs, or management recommended by health authorities and water utilities
Why containing these weeds with a weed boom is important
1) Prevent downstream spread and reinfestation
Once floating weeds move into connected waterways, the affected area expands and control becomes harder. For weeds that spread by fragments, containment reduces the chance of new infestations forming downstream.
2) Protect infrastructure and reduce operational disruption
Weed booms are used to prevent floating weeds and debris from spreading downstream and to enable collection at a controlled point. This supports protection of culverts, drains, pumps, screens, and offtakes.
3) Support faster, safer removal
Containment concentrates floating loads so removal crews can work from one access point rather than chasing scattered material across a waterbody. This improves efficiency and reduces the chance of accidental spread during removal.
4) Improve incident response during cyanobacteria events
During cyanobacteria events, a weed boom may help manage where visible surface accumulations drift, particularly around priority assets and access points. It must not be described as treatment or toxin control.
Practical checklist for using a weed boom
- Choose an interception point near an outlet, narrowing, or downwind accumulation zone.
- Plan removal access first so intercepted material can be collected safely.
- Install and tension the boom so floating loads do not bypass the containment line.
- Inspect more often after storms, strong winds, and operational flow changes.
- Remove intercepted weeds promptly and secure them to prevent re entry.
Partner with us to supply weed booms for irrigation channels, farm dams, and pump intakes. We’ll support you with product selection, sizing guidance, and reseller pricing.
