MEGA Stream Act

Maximum Economic Growth for America Through Environmental Streamlining Act (MEGA Stream Act) - Directs the Secretary of Transportation to establish a program under which States carry out Federal responsibilities with respect to one or more highway or transit projects (or classes of projects) under the National Environmental Policy Act of 1969 (NEPA), provisions of this Act, or such other environmental review or decision-making authority of the Secretary as the Secretary deems appropriate.

Sets conditions regarding State assumption of responsibility for projects located within the State for which environmental impact statements are required.

Grants the U.S. district courts exclusive jurisdiction over any civil action against a State for failure to carry out any State responsibility under this Act.

Requires the Secretary to conduct audits to ensure State compliance.

Designates the Department of Transportation as the lead agency for purposes of compliance with NEPA. Sets forth provisions regarding statements of purpose and need for a highway or transit project, determination of alternatives, and public comment.

Makes the Secretary responsible for: (1) developing a schedule for the NEPA process; (2) coordinating efforts to identify and resolve issues that could cause any other Federal agency to oppose or deny project approval or cause delay in completion of the process; (3) developing an agency coordination plan; (4) requesting each relevant Federal agency to participate in the process; and (5) preparing or ensuring that any required environmental impact statement is completed in accordance with the NEPA process.