The Queensland state government has announced it is poised to construct a second shipping project in Gladstone harbour.

The $400 million worth project will allow two-way shipping traffic and effective use of the harbour, Deputy Premier Jeff Seeney said.

"The Gladstone Ports Corporation has identified this as a key component of a 50-year strategic plan to safely and sustainably accommodate future shipping requirements," Mr Seeney said.

The Queensland government at the same time assured the project will go through the process of a vigorous environmental assessment.

"The Port of Gladstone is Queensland's largest multi-commodity port, the world's fifth largest coal export terminal, and one of the busiest ports in Australia," Mr Seeney said.

The project, covering more than nine kilometres and depths of more than 16 metres, will employ 100 people over a 20-month construction period from 2014-2015, and a further 20 people as part of the ongoing maintenance dredging program.

This early, Mr Seeney expects opposition from environmentalists relative to the dredging activity.

"The project involves dredging and soil disposal and, therefore, the co-operation and timely responses from relevant Commonwealth agencies will be very important, to complement our own streamlined approval approached," he said.

The project's draft terms of reference will be open for public comment from October 8 to November 5.

"I encourage the community to participate in shaping the outcome of the EIS and provide input to the draft terms of reference," Coordinator-General Barry Broe said.