Digging up and relocating or securing underground waterworks and data cables along the route of the Capital Metro light rail network could cost taxpayers up to $200 million.
The ACT government has outlined new details of work on the Civic-to-Gungahlin tramway, which has been estimated to cost $614 million.
During an Assembly estimates committee hearing, Sustainable Development Minister Simon Corbell also said a light rail and bus interchange might be located at the present motor vehicle registry site in Dickson.
Mr Corbell said there was expected to be a major increase in property values along the light rail corridor, which will stretch from Civic down Northbourne Avenue and then along Flemington Road to Gungahlin.
Capital Metro acting project director Glenn Bain said $200 million had been set aside for the possible relocation or strengthening of utilities and other infrastructure that lay beneath the Northbourne Avenue median strip and along other parts of the light rail route.
An infrastructure audit would be conducted to determine in more detail what might need to be moved.
''We have broad indications for contingencies to move any utilities that need to be moved or otherwise protect them,'' Mr Bain said.
Mr Bain said early analysis indicated that the light rail system might cost about $7 million a year to run, but cautioned that this figure could not be relied upon. Opposition MLAs questioned the current costings, comparing the light rail to the Cotter Dam Extension.
Opposition Leader Jeremy Hanson said: ''Why is that you basically signed on to light rail before we've got any sense of mature costs? If you've got costs that we know based on the experience of this government have the potential to triple?''
The opposition also requested the public release of economic and engineering studies which had been undertaken.
The $614 million estimated project cost included $54.5 million for trackwork. Vehicles would cost about $11 million each.
Mr Corbell told the committee that a tram station could be located at or near the current motor vehicle registry site on Challis Street in Dickson, but more analysis needed to be done before this was confirmed.
''It also has the potential to be an interchange so that people can interchange between bus and light rail at that point,'' Mr Corbell said.
Mitchell was being considered as possible location for a ''park and ride'' facility for Gungahlin and motorists who wanted to catch the light rail.
Mr Corbell said there would be an ''uplift'' in property prices along the Northbourne Avenue corridor and intensification of development there.
''It is difficult to fully quantify what the exact level of uplift will be. But we do know there will be an increase of land value along the corridor, based on the experience of other projects
nationally and internationally,'' he said.
Mr Corbell said home owners living close to the light rail path would have to pay higher rates as their property values rose but would benefit from easy access to the service.
''Yes, they may see higher rates because they see higher property values. But there will be other savings accruing to those households. Those households may feel that they don't need to own two cars, or even one,'' he said
Liberal MLAs reacted with sarcasm when Mr Corbell said light rail would help create ''liveable human places'' in Canberra.
Mr Hanson asked: ''Can you give me an example of a city that you know that isn't a human city?''
''By human,'' Mr Corbell responded, ''I mean giving priority to people rather than cars''.