Fluorescent green water appeared at North Coogee after a plumbing dye entered the stormwater system, prompting safety warnings for beachgoers to stay clear of the affected section of the shoreline.
Investigation Into The Green Water
Bright green water was seen at North Coogee on the morning of 28 November 2025 after liquid flowed from a stormwater outlet and discoloured the surrounding area. Images shared online showed the fluorescent colour along the shoreline, drawing immediate attention from residents and swimmers.
Environmental Health Officers inspected the site shortly after the first reports were made, focusing on the northern end of the beach where the water appeared most concentrated.
Cause Identified As Plumbing Dye
The assessment determined that the substance was fluorescein, a water-soluble dye commonly used by plumbers to trace the movement of water through sewer and stormwater systems. The dye is designed to be highly visible so that leaks or flow paths can be located quickly.
Officers advised that fluorescein is considered non-toxic and odourless in the environment. However, it can cause skin irritation for some people, leading to safety advice for beachgoers to avoid touching the discoloured water.
Safety Advice And Beach Conditions
Council officers confirmed that North Coogee remained open during the incident, though lifeguards directed swimmers away from the green-coloured area as a precaution. Authorities explained that the dye typically disperses naturally within a few hours once it enters open water.
No further risks were identified during the investigation, and the discolouration was expected to fade without ongoing impact.
Community Reactions In North Coogee
Residents shared concerns online, linking the dye incident to broader frustrations about stormwater drainage and pollution at Coogee Beach. Comments noted recent occasions where storms had washed debris, rubbish and microplastics into the area.
Others remarked that similar dye-related discolouration had occurred previously. These remarks reflected community sentiment expressed through public comments rather than official findings.
Next Steps
The council indicated that no additional actions were required once the dye dispersed. The event renewed local discussion about how quickly substances can enter the water from stormwater systems at North Coogee, with community members continuing to raise wider environmental concerns.
Published 2-Dec-2025
