Prior to recommending to the Legislature the approval for state assistance of any project, designed in whole or in part for flood control, adopted and authorized by Congress, and prior to the submission to the Legislature of an estimate of the total cost to the State, and prior to recommending an appropriation by the State in aid of any such project approved for state assistance by the Legislature, the department shall obtain from the appropriate agency of the Federal Government an estimate of the total cost of the project and the cost and benefit ratio, based upon then current construction costs and values, and shall submit the same to the Legislature.