Canberra cannot rely on building bigger dams or piping water from the Murrumbidgee to ''create a buffer'' for future urban growth, a leading environmental scientist says.

University of NSW ecologist Professor Richard Kingsford said the city's growth would inevitably be curbed by climate change, and a rapidly rising level of increased water scarcity across the Murray-Darling Basin.

''We have to get serious about reducing water urban use, and we also have to lose the fudge factor around population and unchecked urban growth. We can't just think in terms of building more dams and pipelines to capture and store water. That's outdated thinking,'' he said.

Speaking in Canberra last night, Professor Kingsford said the basin - Australia's biggest food production region injecting $15 billion into the national economy - had ''dodged an environmental bullet'' with recent floods.

Delivering the Eric Rolls memorial address at the National Library in Canberra, Professor Kingsford said all Australians had to face the challenge of learning to live with less water in future.

''The choices are stark - be clever and reduce our demand for water and protect our rivers or build more dams and develop more rivers,'' he said. ''The former will be a path to sustainability and the latter will just increase our water footprint. It's high time we learned to adapt to our land of droughts and flooding rains, rather than failing time and time again to try to make it adapt to us.''

Speaking before the memorial address, which honours NSW farmer and award-winning environmental writer Eric Rolls, Professor Kingsford said Canberra could not expect to increase its take of water from the basin's river systems.

''After Adelaide, it's the second biggest city in the basin, and any water it takes from the rivers means less water for wetlands, flood plains and food production. More water for Canberra's new suburbs means less water for farmers further down the Murrumbidgee at Coleambally and less water for the low 'bidgee wetlands,'' he said.

The CSIRO has previously warned worsening climate change would force farms and towns along the Murray and lower Darling rivers to live with 41 per cent less water within 20 years.

''We live in the world's driest inhabited continents and so we should be leading the world in water management but we are profligate with our water use,'' Professor Kingsford said.

''We have the second highest per capita level of water use in the world, topped only by Turkemenistan - we use more than two and half million litres a year.''