Seaplanes on Lake Burley Griffin are a step closer following support from lake users for this month's trial landing and taking off from the Central Bank, with the trial also used to assess the heritage and environmental impacts of permanent flights.
The National Capital Authority said independent experts were commissioned to assess various aspects including environmental matters.
Asked to elaborate, NCA chief executive Sally Barnes promised several thorough environmental assessments were undertaken over the five days.
"Environmental assessments are taken on noise, displacement - any other environmental impact - for example, any birds and threatened species, all of that," Ms Barnes said.
Ms Barnes said the NCA expected to receive the reports in coming weeks and the aim was to have seaplanes operating by spring.
The NCA's previous environmental assessment was during a demonstration flight in 2021. A noise assessment concluded it met the ACT regulations and an observation of bats concluded they were not disturbed.
Despite the NCA suggesting otherwise ahead of the most recent trial, the environment assessment did not address concerns from ACT ornithologist group Canberra Birds on the impact to bird life.
Member Chris Davey, a retired CSIRO bird research officer, said there didn't appear to have been any environmental impact assessment done on safety or noise issues concerning birds.
Mr Davey said the main concern was for bird populations on Lake Burley Griffin, the Jerrabomberra wetlands and Fyshwick ponds.
He said seaplanes potentially posed a risk to silver gulls migrating to Spinnaker Island and pelicans, cormorants and swans on the lake.
Mr Davey said a trial flight in March wouldn't produce any evidence of what impact seaplanes might have from August through to December.
"It has to be done during the breeding season of the silver gulls," he said.
"It'd be pointless doing it now because this is about birds using the island."
In response to questions from The Canberra Times the NCA said seaplanes will primarily operate around Acton Peninsula and away from Spinnaker Island where silver gulls are known to migrate.
"South Coast Seaplanes have advised that NSW National Parks and Wildlife Service have conducted observations of the birds during take-off and landings in Moruya and no reaction from the shorebirds species were observed," a spokeswoman said.
"The NCA is aware of the migratory silver gulls on Spinnaker Island and is committed to ensuring that they are protected during the nesting season.
"The seaplane operators will be provided with the location where the silver gulls nest so that this is incorporated into their operating manuals, the same procedure as they would for other areas."
The ACT Greens have confirmed they share some of the community's concerns about introducing seaplane flights from the lake to Sydney and the South Coast.
Greens leader Shane Rattenbury said early-round consultation on the proposal suggested seaplanes might be electric and, given that now seemed not to be the case, the Greens were concerned about the amount of emissions generated.
"While the seaplanes might seem like a fun and novel idea, the reality is that they will generate more emissions and potentially impact the enjoyment of the lake had by the many Canberrans who row, swim, sail and paddle on it every day," he said.
"With only a small number of passengers on each flight, it would be interesting to know what the emissions per head is compared to regular commercial flights.
"If we really want to boost tourism and create better connection between Canberra and Sydney we'd much rather see improvements to our existing rail network."
Zena Assaad is from the Australian National University's School of Engineering and specialises in air traffic efficiency and fuel consumption.
She said it was difficult to quantify the emissions for a seaplane flight between Canberra and Sydney or Canberra and the South Coast because there were too many variables.
Dr Assaad said the number of passengers and how long aircrafts were made to wait for take-off or to land would influence fuel consumption from flight to flight.
She said aircraft had become more fuel-efficient over time and the age of the vehicle would also impact emissions.
"But by comparison to a car or a train or an electric vehicle - they're not very fuel-efficient," Dr Assaad said.
Dr Assaad agreed with Mr Rattenbury that investment in transport between Canberra and Sydney could be better directed elsewhere.
"Honestly, the east coast is in dire need of a high-speed train system," she said.
Dr Assaad said opponents' arguments the cost was too great were irrelevant.
"Do we have to make our money back? I think a high-speed train system across the east coast would be considered critical infrastructure," she said.
"If you could get on a train and get from Canberra to Sydney in an hour or an hour-and-a-half - instead of having the highway or having flights between the two - I imagine that that would be a lot more efficient than trying to add additional seaplanes."
We've made it a whole lot easier for you to have your say. Our new comment platform requires only one log-in to access articles and to join the discussion on The Canberra Times website. Find out how to register so you can enjoy civil, friendly and engaging discussions. See our moderation policy here.
