Residents fear North Stradbroke Island's sacred lagoons drying

An online petition calling for increased management and assessments on the island attracted more than 500 signatures.

It said harsh weather conditions had led to concern about the affects of water shortages on island ecosystems and townships, especially in fire season.

Resident Dale Ruska said residents had noticed decreasing water levels at spots including Eighteen Mile Swamp and Brown Lake.

"We're sitting on the island watching our sacred water holes and sacred lakes drying up before our eyes," he said.

"This causes a lot of concern for the Aboriginal people and it's something we'll be fighting really strongly for, because our island needs water."

A Seqwater spokesperson said earlier this month that the company was using about 50 per cent of its water allocation on the island.

Groundwater extractions on the island averaged 1.6 megalitres a day for supplying the island community, while about 25 megalitres was taken for supplying the south-east water grid.

The island provides up to 60 per cent of the Redlands' water supply.

"Currently, the amount of water taken from Minjerribah is directly related to how much water is used in the Redlands Coast community," the spokesperson said.

Water restrictions would not be considered unless south-east Queensland experienced a failed wet season.

"Based on current modelling the earliest restrictions would need to be considered is mid-2020," the spokesperson said.

Mr Ruska said many people were concerned about saltwater encroachment.

"That would have devastating effects on the environmental qualities and integrity of this place."

Cr Peter Mitchell said science behind sustainable water use on the island was robust and residents should be alert, not alarmed.

"I strongly encourage residents to ask questions through the right authorities," he said.

A Quandamooka Yoolooburrabee Aboriginal Corporation spokesperson said QYAC had worked with the state government to understand better the current state of inflows, extraction and interactions with the environment.

"Minjerribah has the most stable body of freshwater, Kaboora, also known as Blue Lake, on the planet," the spokesperson said.

Cr Mitchell said council had also been facilitating communication between residents and Seqwater, including at a township meeting in September.

He understood Seqwater would soon be briefing councillors about their plans for water extraction from the island.

Mayor Karen Williams said in November that she would work to ensure the state government understood the importance of water security and its cultural connection to the island.

But Mr Ruska said a review was needed of water extraction on the island.

"The country's already in drought, it's already burning and we've experienced that over here as well," he said.

"If they want to ensure that this island's integrity is going to be safeguarded....they need to more or less turn off the taps for a while."

The Seqwater spokesperson said reducing demand was a key way to reduce water supply off the island, particularly through the peak summer holiday and tourism season.

"Seqwater will continue to monitor water supply on the island closely."

Seqwater's drought response plan includes a water conservation campaign.