Sydney Airport, the main gateway into Australia, is close to capacity with increasingly long delays forecast and a knock-on effect across the country, a new study showed Tuesday.
The report, conducted by consultants Booz and Company for a government inquiry into possible sites for a second airport, predicted five-hour delays within a decade without another facility.
It also highlighted the airport's limited ability to accommodate new flights, stifling growth.
Almost half of all scheduled flights in Australia land or take off at Sydney's Kingsford Smith Airport and there have been plans for a second site near the city for 30 years.
So far nothing has materialised with several areas proposed and rejected.
The federal government though has once again committed to nominating a site this year and Infrastructure and Transport Minister Anthony Albanese admitted it was becoming urgent.
"It's clear Sydney needs a second airport sooner rather than later," he said.
"Without action the national economy will be constrained with a negative impact on growth and jobs."
According to the airport website, during the period 2000-2009 the annual number of passengers passing through the facility increased 30.7 percent to 33 million. This represents an average annual growth rate of 3.1 percent.
The study, published in the Sydney Morning Herald, highlighted the burden on passengers through the day if morning flights were disrupted.
By 2015, it suggested that if flights were limited to 55 an hour in the 7am-9am peak due to bad weather, it would take three hours for the airport's schedule to recover.
The delays would have a knock-on effect at other airports whose flights link with Sydney.
By 2020, the same morning delay would set back the flight timetable by five hours, it said.
Despite the warnings and Albanese insisting a second airport was needed, New South Wales state Premier Barry O'Farrell on Tuesday made clear he is against the idea.
O'Farrell, who was elected last month when his right-leaning Liberal/National coalition crushed Labor to end the party's 16-year grip on the state, said such a project would cause enormous grief to local residents.
He favours developing fast train services to link the country's main east coast capitals to lesson the domestic flight burden at the airport.
"I cannot envisage where in the Sydney basin you'd put a second airport," he told local radio.
"Whether the Central Coast, the south west, or the western suburbs, find me an area that is not going to end up causing enormous grief to people who currently live around it.
"I've always believed... that the way to address this was through fast train links," he added.