The Swiebodas are selling out and moving their business to Nagambie - 115 kilometres from Melbourne. They are hoping it will take the city a while to get that far. Melbourne's urban sprawl - the city is expected to expand by another 41,000 hectares in the coming weeks - is just one symptom of the creaking strains of massive population growth. Melbourne and Victoria are growing at record levels - Melbourne is increasing by up to 1800 people a week - driven by increased birth rates and people moving to the city. Last year, more than 71,000 babies were born in Victoria - the highest since 1971. A State Government report predicts that by 2036, Victoria will grow by 2.3 million people, with 1.8 million extra people in metropolitan Melbourne and about 477,000 in regional Victoria. An additional 600,000 dwellings will be needed over the next 20 years, of which 284,000 are anticipated in growth areas - 134,000 beyond Melbourne's current boundary. By 2049, Melbourne is expected to have close to 7 million people. But while proving an economic bonus for home builders and the Victorian economy, the state's population has pushed many services to the brink of collapse and threatens long-term environmental impacts.

This has led some, including former Australian of the Year Tim Flannery, to call for an independent board - simliar to the Reserve Bank - to monitor and determine population growth and immigration. The committee would be independent of government and politics and would consider economic, environmental and social factors - including birth rates and assistance for refugees - when setting immigration and population levels. Flannery says immigration is ''far too important to be left to government. Government will always want more taxpayers and business will always want more customers - so put the two together and you'll get a recipe for endless population growth.'' An Age/Nielson poll shows four in 10 Australians believe Australia's projected population of 35 million by 2049 will be too many. The effect of rapid population growth is something Victorians are increasingly familiar with - and frustrated by. Public transport and roads are crowded - public transport patronage has grown far more rapidly than the Government had planned.

Green wedges are being sliced up for development, and environmental flows to struggling rivers such as the Thomson and the Yarra cut to provide more water for Melbourne. The state's power supplies are at tipping point as air-conditioners are cranked up across the state. Last summer, during a trifecta of 40-plus-degree days, the power grid went into meltdown with electricity cut to many suburbs. The national energy industry body has predicted that without new power supplies, Victoria will be running dangerously low in a little more than three years. Water restrictions have been in place for years, childcare and kindergarten places are difficult to find in many places and public housing is in short supply. Melbourne is feeling the pressure of success.

Premier John Brumby is aware of the challenges posed by Victoria's population explosion. In a speech last week he warned: ''There are some clear and present threats to our liveability - none more than the challenge of managing population growth in the face of new pressure on resources and infrastructure.'' Australian Education Union Victorian president Mary Bluett says schools are already experiencing strong demand in many locations because of population growth. She warns that the baby boom which created long waiting lists at Melbourne's childcare centres and now kindergartens will hit schools soon. ''I think we are about three years away from the big wave coming into primary schools,'' she says. In health, Melbourne's public hospitals are also feeling the pressure. According to the Government's latest hospitals report, Victoria's hospital system passed five of the Government's nine performance benchmarks. About 86,000 people waited longer than eight hours in emergency departments before they were transferred to a bed - 2000 more than during the previous year - and nearly 22,000 patients on the elective surgery waiting list waited longer than they should to receive operations.

Opposition Leader Ted Baillieu believes inadequate planning for the massive population growth is leading to stretched services and anti-social behaviour. ''I think we are vulnerable in dislocation and disenchantment and that's manifesting in many ways. But I would suggest that is manifesting in the rising tide of anti-social behaviour,'' he says. Public Transport Minister Lynne Kosky yesterday pointed to Melbourne's growth and said that by 2036, there would be half a million more people in the city's west. The Government has proposed two rail projects to cater for the west's growth: a $4 billion rail line from Werribee into the CBD, allowing V/Line trains to run direct, and an $8.5 billion rail tunnel for metropolitan trains from Footscray to Caulfield. The rail tunnel, at this stage, is little more than a concept, with $40 million set aside for a feasibility study. The project is totally reliant on Federal Government funding and, even if it receives the cash, construction will not start until at least 2017. For Monash University's Professor Graham Currie, the way to cater for massive population growth is straightforward: pump money into new buses, train and tram lines instead of building new freeways in the city's inner suburbs.

He says the recent $1.4 billion M1 freeway widening project, which has seen a lane added in each direction to the Monash and West Gate freeways, will be seen by future generations as a terrible mistake. ''For a long time, we will look at these ugly flyovers and we will regret it,'' he says. Currie says a congestion tax applied to cars is essential, with the money to be then pumped into paying for better public transport. ''It's crucial for how we deal with growth, because anyone who is making inefficient use of the road will be charged, and the money can be used on making public transport better,'' he says. For instance, the $8.5 billion train tunnel from Footscray to Caulfield - an idea first proposed by Currie - would carry the equivalent of 24 lanes of freeway traffic, he says. Many also have environmental concerns with the huge growth. Green Wedges Coalition joint co-ordinator Rosemary West has called for a population summit to discuss a sustainable rate of growth and whether the public wants Melbourne to keep growing.

Australian Conservation Foundation president Professor Ian Lowe says Australia is living beyond its means and immigration levels need to be reduced to below a quarter of the current annual intake. He says Australia can still help refugees while managing an immigration intake that improves sustainability. Federal Labor MP Kelvin Thomson has backed the call for a population summit. He says Victoria's infrastructure and services are not coping with current growth and will struggle with forecast growth. STATE Treasurer John Lenders defends Victoria's growth. ''New Victorians mean more jobs for the Victorian construction, retail and manufacturing industries,'' he says. ''There is no doubt that Melbourne is a popular place to live with an attractive lifestyle, a resilient economy and the cheapest housing on the eastern seaboard.'' Water Minister Tim Holding also shrugs off any threat to Melbourne's water supply. He says major water projects that are complete or under way for Melbourne, such as the desalination plant and the north-south pipeline, will ensure that the city has enough water.

''Melbourne will have on average an additional 225 billion litres of water, which is about 50 per cent of our current water needs, so we have factored in a growing population in our long-term planning,'' he says. But others point to problems with Melbourne's development plans, predicting that if the current rate of growth continues, Melbourne will become a sprawling metropolis like Los Angeles. Planning Minister Justin Madden says the Government does not apologise for population growth and it is ''one of the reasons why Victoria has done so well in an economic sense''. He says as well as development in the growth areas and a renaissance in regional Victoria, Melbourne is already seeing ''intensification'', with taller buildings and developments along transport routes. Madden maintains that Melbourne benefits from some of the most affordable housing of any capital city in Australia. But, in a surprising move, the Planning Minister predicts that after the next 41,000-hectare expansion of the urban growth boundary, the boundary will not be moved again in his lifetime.

''I don't believe that we will need to make adjustments to the urban growth boundary again - certainly not in my life time,'' he says. But others say the 41,000-hectare expansion is already bad planning. Professor Kim Dovey of the University of Melbourne's school of design says it will leave Melbourne a ''a very unsustainable city''. Instead, he has called for boosting population in regional centres with faster links to the regions. Dovey says Melbourne can absorb population growth within current boundaries. ''Melbourne is a very, very low-density city and can absorb very large amounts of intensified development, on tram and rail lines and in activity centres, without damaging Melbourne's urban character,'' he says.

Loading Out in Mernda, the horses are long gone - off to Nagambie, where Melbourne's population boom and the urban sprawl is yet to reach. Jason Dowling is city editor. Clay Lucas is transport reporter.