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On the Gold Coast, we have a diverse and well-managed water supply system, but have you ever wondered about the origin of your tap water? This guide will take you on a journey through the Gold Coast’s water supply, treatment procedures and whether the water is safe to drink!

Where does Gold Coast’s drinking water come from?

Gold Coast’s drinking water comes from a combination of sources, including bulk water collected from local dams within the South East Queensland (SEQ) Water Grid: the Hinze Dam and the Little Nerang Dam.

Seqwater, the region’s bulk water supply authority, then treats the water and ensures it meets the stringent standards set by the Australian Drinking Water Guidelines.

City of Gold Coast delivering water to the Gold Coast

Source: City of Gold Coast

What does the water treatment process look like?

Drinking water is cleaned and treated at water treatment plants situated across the region from Molendinar and Mudgeeraba. These water treatment plants are owned by the Queensland State Government, but the task of distributing water is entrusted to the City of Gold Coast who monitors for water quality issues across 65 reservoirs and regulates the water treatment process.

The basic water treatment processes include coagulation, flocculation, sedimentation, filtration and lastly, disinfection of water and pH correction. Let’s take a closer look at each step in the process:


Coagulation is the first stage, where specific chemicals such as liquid aluminium sulphate are added to the raw water to bind with dirt and other particles. These form larger particles called “flocs,” which are then simpler to remove by settling or filtration.

Flocculation & Sedimentation

After coagulation, the water is slowly stirred in the flocculation process. This encourages the newly-formed particles to gather into more substantial, thicker particles that can be more readily settled out. Following flocculation, sedimentation occurs where these large clumps settle to the bottom, leaving the clear water above.


After the initial stages of coagulation, flocculation and sedimentation, the water may appear clear, but it may still contain minute contaminants. These contaminants can include small particles, bacteria, viruses and other microorganisms that can cause diseases if not removed.

This is where filtration comes into play. The clear water is passed through layers of natural filtering materials such as sand, gravel or even activated charcoal. These materials act as a sieve, trapping and holding the remaining impurities, ensuring that even the tiniest contaminants are removed.

Disinfection & pH Correction

The final stage is disinfection, where substances like chlorine are added to kill any remaining germs. pH correction ensures that the water has a balanced pH level, typically adjusted to be between 6.5 and 8.5, that’s safe to consume and minimises corrosion or scaling in the water distribution system.

The following video is a great resource explaining Seqwater’s role in making the water supply for the Gold Coast safe for drinking.

Gold Coast Desalination Plant

A climate-resistant water source, the Gold Coast Desalination Plant plays a vital role in the region’s water supply. It uses advanced reverse osmosis technology to transform seawater into drinking water by first removing the salt then remineralising the water ready for distribution to homes, businesses and industries in the region.

During times of drought or when other water sources are strained, the plant ramps up production, ensuring a continuous water supply. And just with water treated from dams, desalinated is regularly tested to ensure it is clean and safe to drink.

safe tap water being poured from a jug into a glass

What’s in the tap water?

Other than the trace amounts of chlorine added during Gold Coast’s tap water contains essential minerals like calcium and magnesium, contributing to its taste.

Fluoride is also added to the water supply, a common practice in many parts of the world, endorsed by various health organisations. The fluoride helps to promote dental health by strengthening tooth enamel, reducing the incidence of tooth decay, especially among children.

Is Gold Coast water hard or soft?

Hardness in drinking water is mainly the result of the presence of large amounts of two minerals – calcium and magnesium. These hard minerals contribute to limescale buildup which can lead to pipe corrosion and reduced water pressure and flow. Hard water also has a negative impact on the lifespan and efficiency of certain appliances that need water to operate: kettles, dishwashers and water heaters, to name just a few.

The water in the Gold Coast is considered to be relatively soft, meaning it has fewer harsh minerals that can damage appliances and irritate skin. Having access to soft water can help extend the lifespan of water-using appliances and even increase the effectiveness of soap!

Water quality testing

Drinking water should be safe to use, clear and colourless, with no unpalatable taste or odour, and it should contain no suspended matter, harmful chemical substances or pathogenic microorganisms.

Regular and comprehensive water quality testing is conducted across the Gold Coast to ensure that the drinking water meets or exceeds the Australian Drinking Water Guidelines. These tests check for a wide range of factors, including microbial content, chemical levels and physical appearance. This rigorous monitoring ensures that the water remains safe and of high quality.

Is Gold Coast drinking water safe?

Yes, the drinking water on the Gold Coast is considered safe for consumption. The rigorous treatment process and regular testing ensure that all drinking water complies with strict quality standards. Any potential contaminants are removed or reduced to safe levels, providing confidence in the tap water’s safety.

The City of Gold Coast has even introduced its Choose Tap program that encourages locals to drink tap water as a convenient, environmentally-friendly and low-cost alternative to purchasing bottled water. The Choose Tap program offers access to free drinking water where people need it most and so far, over 30 permanent water refill points with water bubblers and two bottle-filling nozzles have been installed at prominent Gold Coast locations.

Gold Coast waterways and skyline

Keep a steady supply of water in your Gold Coast home or business

From natural sources like dams to the advanced Gold Coast Desalination Plant, the region ensures a reliable and robust water supply. Regular testing and adherence to national guidelines provide assurance that the water is not only safe to drink but also maintains its quality and taste.

For all your plumbing needs in the Gold Coast area, contact our friendly team at Ryan Old Plumbing. We can help answer your plumbing questions or arrange a visit to provide you with a quote.