Warning signs will be positioned at recreational areas around the reservoir and will remain in place while high levels of blue-green algae are present.

GMW Water Quality co-ordinator Bianca Atley said the reservoir would not be closed to the public and visitors could still sightsee and enjoy other activities that did not involve direct contact with the water.

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"If people are near the water or on a boat, they should take care to avoid direct contact with the water," she said.

Blue-green algae occur naturally in waterbodies and contain toxins harmful to humans and animals.

Characteristic signs of algae contact are skin rashes or itchiness; sore eyes, ears and nose; or if swallowed, nausea or vomiting.

GMW recommends:

It is not possible to predict how long the algae will remain at high levels, but GMW will continue to monitor the situation.

It has been four years since such a high level of blue-green algae was detected at Laanecoorie Reservoir and this is the eighth warning issued at the waterway in the past 20 years.

Water supplied by GMW is not suitable for human consumption without first being properly treated.

OTHER STORIES:

Human consumption includes showering, bathing, washing, cooking, ice making and drinking.

Keep up to date with current blue-green algae warnings at g-mwater.com.au/news/bga or by ringing 1800 013 357.

For more information about blue-green algae and your health, visit health.vic.gov.au or phone NURSE-ON-CALL on 1300 606 024.

For advice on eating fish from affected waters, go to betterhealth.vic.gov.au/health/healthyliving/Harmful-algal-blooms

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