The entire project - also including a memorial, visitor centre, garden, hotel, convention centre, amusement park and research institute - is estimated to cost Rs. 2,500 crore.
It has now emerged that the Gujarat government did not seek statutory approvals from the Centre's environment ministry for the grand project, and started preparatory work it near the Sardar Sarovar Dam.
"This is clearly illegal," says a letter by a group of environmentalists from Gujarat and other states to environment secretary V Rajagopalan. They say that laying of the foundation stone for the project and starting the work without social and environmental impact assessments violates the Environment Protection Act, 1986.
"We are looking into the issue," a senior environment ministry official said. The ministry will decide in a couple of days whether to send an inquiry team to Gujarat or issue a notice to the state government.