Native water rat, rakali, under threat from Brisbane southside residential development

2021-07-15

A draft plan for more apartments and industry in a southside Brisbane suburb may put the home of one of Australia’s most elusive aquatic creatures at risk, a freshwater scientist says.

Key points:

• A secretive native water rat lives in a southside Brisbane creek

• A council plan to increase suburban density may affect the creek, one scientist says

• That could put the rat’s home at risk

Brisbane City Council’s draft neighbourhood plan for the suburbs of Moorooka, Salisbury and Nathan proposes to increase industrial, commercial, and residential development in parts of the suburbs.

A secretive creature

But freshwater scientist and long-term Salisbury resident Alisha Steward has raised concerns the proposed density increase could impact upon creeks flowing through the suburbs.

That includes Rocky Waterholes Creek, which is home to a surprising urban population of Australian native water rats, spotted by locals on more than one occasion.

“You could almost call it the Aussie otter,” Dr Steward told ABC Radio Brisbane.

“It’s just a beautiful creature, it’s got water-repellent fur, it’s got partially webbed hind feet and it’s quite large, it’s about the size of a platypus.”

The stocky, water-loving rat is a far cry from the typical brown rat living in waterways across much of eastern Australia in its own territories.

The native water rat is also known as the rakali, an Indigenous name.

A top-flight predator, the rakali is easily identified by its white-tipped tail and, as an aquatic rodent, spends most of its time in and around creeks, living off crustaceans, insects and fish.

“It’s found throughout Australia, really, but it’s a very secretive creature so not many people have seen one,” Dr Steward said.

A suburban home

Dr Steward said, despite the existing industrial precincts around the creek, the rakali must have found a good mix of habitat, shelter, and food to have such a strong population.

Water samples showed a strong mix of insects and bugs and even freshwater prawns, she said.

Dr Steward said she was concerned the council’s proposed suburban infill could create ‘urban stream syndrome’.

“We see more and more development gobbling up backyards, gardens, [and] these areas are really important for the filtration of rainwater,” Dr Steward said.

“You can imagine rain falling down and it’s hitting the garden soaking in … and getting into the groundwater.

“But when you get … more roofs and driveways, that’s all capturing that water, creating overland flow and we’re getting these really flash flows into the creek.

“If we’re getting an increase in all these hard surfaces that rainwater can’t get through, then we’re really going to see impacts with the creek.”

Brisbane City Council Deputy Mayor and city planning chair Krista Adams said ecologically significant areas within the draft plan were highlighted, including Rocky Waterholes Creek.

“Once the latest round of community feedback is received, technical studies and targeted investigations, including into stormwater, will be completed,” Cr Adams said.

“The findings of these environment assessments and community feedback will be considered during the preparation of the neighbourhood plan.”

Public consultation on the plan is open until July 26.

abc.net.au, 15 July 2021
; https://www.abc.net.au