The department of Business Enterprise and Regulatory Reform (BERR) requires the SEA as a vital part of its two-year long feasibility study for the project, first announced in January.
Secretary of state for energy, John Hutton, said: "A Severn tidal power project could be larger in size, output and cost than any other energy project in this country. It has the potential to generate up to 5% of the UK's electricity demand and contribute significantly to the proposed EU renewable energy targets."
"It is therefore vitally important we undertake the most thorough and exhaustive study and contract the right companies to take this work forward," he added.
The 5% figure is based on various studies undertaken in the 1980's which showed that a tidal barrage constructed between Cardiff and Weston could produce up to 17 Tera Watt Hours of electricity a year.
Within the week, the consortium is expected to issue a Call for Evidence to request any proposals or existing data which could help develop the project and elucidate its possible impact on the environment.
Other members of the consortium also include Black & Veatch, the Environment Council, Environ, ABPmer, HR Wallingford, Hartley Anderson and George Corderoy.
The Welsh Assembly's minister for the environment, Jane Davidson, said: "I am very much aware of the estuary's environmental importance and the environmental protection legislation that, quite rightly, will need to be taken fully into account."
"There is a great deal at stake and our assessments during the feasibility study must be rigorous and based on sound science."