A leading ecologist claims the ACT Government misled him over development plans for the Molonglo Valley when he was hired to provide an environmental assessment of the site.
University of New England bird expert Stephen Debus said he was not informed of plans to dam the Molonglo River and flood wedge-tailed eagle nests and habitat to form an artificial lake.
''If I had been told about the dam, I would have written a very different report,'' he said.
But a spokeswoman for the ACT Planning and Land Authority claims Dr Debus finalised his first report ''well prior to the technical reports that identified an online dam as a feasible option for stormwater management.''
Dr Debus, author of a field guide to Australian birds of prey, has accused the ACT Government of selectively cherry-picking science in the two reports he wrote to ''justify the proposed development or suggest minimal impact on raptors'' in the river valley.
In a six-page statement to be posted online later this week, he is urging Canberra residents to obtain his reports under freedom of information ''and compare what I said with what apologists for the development are saying''.
The ACT Government wants to build new suburbs to house up to 70,000 people in the Molonglo Valley area between Belconnen and Weston.
The Government has placed a 20-year moratorium on development in the central Molonglo region following community concerns over clearing of remnant native woodlands, but is currently considering a variation to the ACT Territory Plan so development can proceed in the eastern and western sections of the valley.
Dr Debus said his reports contained several warnings about the need to retain ''adequate foraging habitat around nest sites'' for birds of prey, but these were ignored by the ACT planning authority.
During his survey of the site, he was given the impression the Government ''was talking of building maybe a small pond to take some of the stormwater''.
Dr Debus said the Government ignored his recommendation for ''a much more in-depth study'' to assess the impact of the housing development on food sources and nesting sites of birds of prey across the region.
University of Canberra raptor ecologists Jerry Olsen and Esteban Fuentes surveyed the site in 2004 and were also not told of plans to dam the river.
Mr Olsen said, ''They kept it from us. The first we knew about it was from a glossy brochure in our letterbox.''
ACT Planning Minister Andrew Barr said the Government had ''no commitment'' to building a dam on the river.
''A lake is one of many water-management options under consideration. The Government has asked the Planning and Land Authority to undertake a thorough investigation of stormwater management options for the Molonglo.
''The analysis will include investigations from environmental, social and economic perspectives to compare the performance of these options. This information will inform the consequent environmental impact statement,'' he said.