The Wilderness Society challenged the decision to approve the hut and helipad project at Lake Malbena, arguing it should have been assessed against the Environmental Protection and Biodiversity Act.

Barrister Emrys Nekvapil said the impact of the development in the area had not been properly considered.

"Instead mitigation measures have been drawn in [to the proposal]," he said.

"You come out with measures unlikely to have a significant impact."

Mr Nekvapil presented photos to Justice Debra Mortimer of the Lake Malbena area.

"You can see that Lake Malbena is an area of relatively high wilderness value," he said.

"There are not many wilderness places left."

LAKE MALBENA STORY FROM NOVEMBER 2018:

Mr Nekavpil said it was unclear how many helicopter flights would be made.

Under the proponent's proposed package, there would be up to a maximum of 120 people on Halls Island out of about 240 days in the year, not operating in winter, 60 days of which the helicopter would be flying in and out, he said.

"Because of commercial realities it's likely these will coincide with times of popularity with anglers and bushwalkers who use the area," Mr Nekavpil said.

"The visitors will occupy the island to the exclusion of other visitors unless the proponent grants permission."

Mr Nekavpil said time remoteness was also central to many visitors' experiences, which was not factored into the proponent's application.

Anna Mitchelmore, who represented the Environment Department, said it could not address what was likely to be a significant impact of the development without additional information.

She said the department concluded there would be no significant impact on the Wilderness World Heritage Area from this proposal.

Justice Mortimer questioned how compliance with an approved proposal would be monitored.

She did not formally reserve her decision as she thought both parties would care to make additional submissions in reference to a Federal Court decision regarding a fish farm proposal near Triabunna.

Both parties will supply Justice Mortimer will additional written submissions for consideration.