Exclusive : discovery comes as authorities investigate tonnes of sediment choking creek near development site

This article is more than 11 months old

This article is more than 11 months old

Contaminated water has been discovered spilling from a luxury Gold Coast estate development into a Ramsar-listed wetland site, amid a broader investigation into an unfolding “environmental catastrophe” at the once-pristine waterway.

On Thursday the Gold Coast council notified the Queensland Department of Environment and Science that a “private recycled water main” at the Serenity Cove site had broken. Guardian Australia understands the contamination is likely grey water, which authorities advise has the potential to turn septic or breed micro-organisms.

The developer of the Serenity Cove estate, joint-venture company Sime Darby Serenity Cove, was recently listed as “discontinued” by one of its Malaysian co-owners and is in the process of cutting its physical and corporate links to Australia.

The discovery comes as city and state environmental authorities investigate tonnes of sediment choking nearby Coombabah Creek, which locals say has settled in the waterway since the same developer conducted dredging and lake expansion works associated with the Serenity Cove development.

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A resident, Steve Jeffery, told Guardian Australia that dolphin pods used to come up the waterway along Coombabah Creek, which is part of the Moreton Bay Ramsar wetland of international significance. Now he can walk across the creek at low tide.

“This catchment used to be alive, the noises at night sometimes would keep you awake, it was a beautiful sound. The fish jumping, the sharks, the giant rays.

“It’s all blocked now. There has been a significant drop in fish and crabs. There are no more waterbirds here. It has absolutely become an environmental catastrophe.”

Jeffery said he had concerns the sediment build-up would compound the impact of the recycled water leak by restricting tidal flows and the ability of contaminants to disperse.

The Australian Conservation Foundation has raised concerns about the situation and says the construction of canals and dredging – the same work undertaken by the developer at Serenity Cove in recent years – is “highly likely to lead to downstream damage” in a sensitive environment.

“I’m sickened to learn of the environmental disaster unfolding at Coombabah Creek,” the ACF nature campaigner Jess Abrahams said.

“A thorough investigation is urgently required.”

Abrahams said the situation pointed to the “gross failure” of federal environmental laws to protect internationally significant areas like Coombabah Creek. The development was approved in 2004 by the federal government, which decided at the time it did not require assessment under the Environment Protection and Biodiversity Conservation Act.

“The disaster unfolding at Coombabah is a direct consequence of this terrible failure (to properly assess the project),” Abrahams said.

“Australia is in the midst of an extinction crisis. Inappropriate commercial projects like these, which destroy the habitat threatened species need to survive, must be reined in for our unique wildlife to have a future.”

In a statement last week, before the leak was discovered, the Queensland Department of Environment and Science said the investigation into the sediment was ongoing.

“DES is continuing to research historical data, including historical aerial photos, and is working with … engineers to determine relevant coastal processes.”

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Malaysian conglomerates Sime Darby and Brunsfield International developed the Serenity Cove estate through a joint venture company, Sime Darby Serenity Cove. The company is registered in Australia but is the wholly-owned subsidiary of another entity registered in the British Virgin Islands.

In 2017 and 2018 Serenity Cove made about $19m selling individual lots, filings to the Australian Securities and Investments Commission show.

Documents from Malaysia show the developer was listed as being “under discontinued operations” in 2018. Internet archives show that late that same year, a marketing website for Serenity Cove was taken down.

The remainder of the undeveloped land has since been listed for sale in a single parcel. Guardian Australia has confirmed that agents do not have an Australian point of contact and are liaising directly with sellers in Malaysia.

The development company’s only current Australian-based director, a Sime Darby employee based in Western Australia, did not respond to repeated calls. Calls to Sime Darby, Brunsfield International and the Serenity Cove sales office – the developer’s registered address – were not returned.

The Gold Coast council said: “The owner of this private main is responsible for the situation and is progressing repairs.”