The Queensland Government's environmental application for approval of the Traveston Dam will only allow it to be half filled, according to evidence heard at today's Senate hearing in Canberra.

Queensland Nationals Senator Barnaby Joyce pursued the legality of building the dam to Stage 2 when the State Government was only seeking environmental approval under the EPBC Act for Stage 1.

Bureaucrats from the Commonwealth Department of Environment and Water confirmed today that the Beattie Government was only applying for approval to build the dam to Stage 1, even though the dam wall and properties acquired indicate construction to Stage 2, Senator Joyce said.

"What is the problem with this? Well, just that it is misleading, dishonest and socially brutal to the lives of people in the area."

According to the bureaucrats, the Traveston Dam would only be allowed to half fill until such time as the Government received EPBC approval for Stage 2.

"This is like building a two-lane road and then only applying to use the left hand lane. This is complete incompetence or government-led misleading of the state.

"The evidence has clarified that on completion, which currently will be well after Brisbane runs out of water, the Qld govt has only done the paper work to half fill it.

"Although nothing about this fiasco is no longer surprising, the Queensland Government is buying land and building a wall that will be for a volume that even if what they apply for is granted will only be half legal.

"Why should people have their properties compulsorily acquired and be turfed out of their homes now for Stage 2 when the Government has no legal approval to fill the dam to Stage 2?

"If the Government is applying for environmental approvals for Stage 1, it should not be allowed to build the dam wall to Stage 2 height and displace people for a Stage for which it has no EPBC approval. Maybe the EPBC act has to be amended to stop people being treated like this by State Governments in the future.

"That the dam will only be allowed to be half full is a metaphor for the current attitude and operation of the Queensland Labor Government in so many areas - it is only half honest."