At such time as a project is found by the Secretary and the Governor of the State in which it is located (or an appropriate State agency designated by him) to be financially feasible, is determined by the Secretary to constitute a reasonable risk under the provisions of this subchapter, and is approved by the Secretary, such findings and approval shall be transmitted to the Congress. Each project proposal transmitted by the Secretary to the Congress shall include a certification by the Secretary that an adequate soil survey and land classification has been made, or that the successful irrigability of those lands and their susceptibility to sustained production of agricultural crops by means of irrigation has been demonstrated in practice. Such proposal shall also include an investigation of soil characteristics which might result in toxic or hazardous irrigation return flows. The Secretary, at the time of submitting the project proposal to Congress or at the time of his determination that the requested project constitutes a reasonable risk under the provisions of this subchapter, may reserve from use or disposition inimical to the project any lands and interests in land owned by the United States which are within his administrative jurisdiction and subject to disposition by him and which are required for use by the project. Any such reservation shall expire at the end of two years unless the contract provided for in section
422e of this title shall have been executed.