Current alert level: Red
The lake is unsuitable for swimming or any other activities that involve direct contact with the water in the lake. The causes of elevated levels of cyanobacteria are being investigated.
Lake Hugh Muntz in Mermaid Waters was constructed in the early 1980s as the first lake in the Robina Masterplan. It is about 17 hectares in area. Lake Hugh Muntz was one of the first urban lakes constructed in Queensland.
The lake often has blue-green algal blooms. Some of these algal blooms affect water quality and can be harmful to you. Care must be taken with any intended use of the lake. We conduct regular laboratory testing of the lake water and provide notices via:
- regular updates on this website
- regular updates in our email newsletter
- signs next to the lake.
Management plan
Download the Lake Hugh Muntz management plan(PDF, 3MB)
Report pollution in the lake
Act now and report a problem using our online form:
REPORT WATER POLLUTION
Email any questions about the lake to lakehughmuntz@goldcoast.qld.gov.au or call us on 07 5667 5988
Lake Hugh Muntz newsletter
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Water quality monitoring
The City undertakes multiple water quality programs at Lake Hugh Muntz.
Environmental water quality monitoring
The lake has two dedicated monitoring locations which are used to examine water quality from the surface down to the deeper sections. This monitoring program is used to inspect parameters such as nutrient levels at multiple depths.
Algae monitoring
There are four dedicated monitoring locations for algae around the lake. Blue-green algae can move with the wind so it is important that each side of the lake is monitored to give a complete picture of the total blue-green algae concentration at the lake.
Mapped monitoring results
Use the following interactive map for the latest monitoring results. Navigate the map by clicking on the blue marks to display the data collected at the site. To learn more about the parameters we use to test and manage water quality, go to Water quality monitoring parameters.
Please also refer to 'Use of interactive maps' in our Terms of use.
Alerts guideline
Water quality monitoring of the lake and reporting is conducted under the guidelines of the National Health and Medical Research Council (NHMRC).
Red Level Alert
Level 1 guideline: ≥10µg/L total microcystins or ≥50,000 cells/mL M. aeruginosa or biovolume equivalent of ≥4mm3/L for the combined total of all cyanobacteria where a known toxin.
Level 2 guideline: ≥10mm3/L for the total biovolume of all cyanobacterial material where known toxins are not present, or cyanobacterial scums are consistently present.
Our action
We will take measures to warn the public that the waterbody is considered unsuitable for primary contact recreation*.
*Primary contact recreation is defined by the NHMRC as 'whole-body contact with recreational activities'. Examples include swimming, snorkelling, children's exploratory activities and wading.
Amber Level Alert
≥5000 to <50,000 cells/mL M. aeruginosa or biovolume equivalent of >0.4 to <4mm3/L for the combined total of all cyanobacteria where a known toxin producer is dominant in the total biovolume or ≥0.4 to <10mm3/L for the combined total of all cyanobacteria where known toxin producers are not present.
Our action
We will investigate the causes of the elevated levels and increase sampling to enable the risks to recreational users to be more accurately assessed.
Green Level Alert
≥500 to <5000 cells/mL M. aeruginosa or biovolume equivalent of >0.04 to <0 4mm3/L for the combined total of all cyanobacteria.
Our action
We will continue routine sampling to measure cyanobacterial levels.
Health guidelines
Swimming at the lake
Lake Hugh Muntz was designed as part of the area's stormwater drainage system, not as a recreational lake. The lake receives runoff from 16 stormwater pipes as well as ground flows. We conduct water quality monitoring regularly and provide health alerts as required.
Safe water quality cannot be guaranteed.
Blue-green algae (Cyanobacteria bloom)
Blue-green algae is a tiny micro-organism that belongs to the cyanobacteria family. The algae can be found in freshwater lake systems when there is an increase in nutrient level, sunlight and stable water columns. Lake Hugh Muntz experiences blue-green algae blooms. To learn more about algal blooms go to Blue-green algae.
You should exercise caution and avoid contact with water:
- where scum or floating debris is visible
- that looks discoloured, murky or smells unpleasant
- near stormwater drains
- for up to 3 days after heavy rainfall
- if you have an open wound or infection.
About the lake
Material extracted from the 17 hectare site was used to build up the surrounding area, providing flood protection for the subdivision. The lake is up to 12 metres deep and has a volume of approximately 280 Olympic swimming pools.
Lake Hugh Muntz is a retention basin for stormwater from 16 pipe outlets. It also receives an exchange of water from the nearby canal. During high tides, this water comes through a pipe under Barrier Reef Drive. More than 4 decades ago when the lake was first constructed, it was freshwater.
During the first decade the lake experienced very low pH. This prevented the growth of aquatic plants in the lake, but the construction of adjacent canal systems changed groundwater in the area from freshwater to saline. This intrusion of saline water helped the system become more pH neutral and aquatic life began to flourish.
Periods of drought have caused water salinity levels to fluctuate. This means that the lake can alternate between freshwater and brackish water (neither saltwater nor freshwater). These changes in salinity can affect aquatic plant growth which is important for water quality.
City of Gold Coast commissioned Griffith University to investigate the use of a one-way valve on the pipe under Barrier Reef Drive as a possible means of reducing inflow of saltwater from the canal system. However, the investigation determined the one-way value would be detrimental to overall water quality as it would create a stagnant environment. Stagnant environments are ideal for blue-green algae growth. Groundwater and water quality monitoring has also proven that tidal canals connect to the lake through groundwater.
The lake's challenges
Lake Hugh Muntz is a dynamic living environment. It has experienced periods of fluctuating water quality including blue-green algal blooms. Therefore, the lake cannot be maintained as a swimming area because water quality cannot be guaranteed.
As with all lakes and waterways in our city, we work to support a healthy ecosystem in Lake Hugh Muntz. There are many factors beyond our control that make it impossible to maintain suitable water quality for such recreation.
These factors include:
- the general design of the lake to depths of up to 12 metres
- the lake receiving inflows from 16 stormwater pipes and urban runoff
- limited tidal exchange
- groundwater inputs
- overland runoff from the surrounding area
- changing and unpredictable climatic conditions.
Due to these factors, maintaining the general water quality of the lake is an extremely complex task. Learn more about who we are working with to take on the challenge.
We only recommend swimming in patrolled beaches, dedicated swimming enclosures and public swimming pools. Miami Aquatic Centre is just a five-minute drive from Lake Hugh Muntz.
Griffith University partnership
We have a proactive approach to addressing Lake Hugh Muntz's challenges.
Our partnership with Griffith University enables us to take on the complex water quality challenge at Lake Hugh Muntz. The university's Australian Rivers Institute has investigated options for reducing future algal blooms at this lake, and across our city's other urban lakes.
For more information, visit our Lake Hugh Muntz water quality project page.
A multi-criteria assessment of 31 potential remedial measures to reduce the reach and frequency of algal blooms has been conducted.