An emergency shall be deemed to exist when flood control works private or public property and human life are threatened with impairment or destruction or have been impaired, damaged, or destroyed by reason of floods or high river stages. Whenever the Governor of the State of Illinois shall declare that such emergency exists, the Department of Natural Resources is authorized to make expenditures, from any funds appropriated by the General Assembly for the purpose of flood relief, for the reconstruction, repair or maintenance of flood control work on any of the rivers and waters of Illinois that may be threatened with impairment or destruction by flood or that may have been impaired or destroyed by flood, or, may authorize the reimbursement of any legally organized drainage district for any expenditures made for the repair, reconstruction or maintenance of any flood control work that may have been impaired or damaged by flood. Provided, that if there be an approved report of survey, as provided for in Section 5 of this Act, for the river or water, including the watershed thereof, on which the impaired or damaged flood control work is situated, no expenditures for the reconstruction, repair or maintenance of said damaged flood control work shall be lawful unless the plans for reconstruction, repair or maintenance of the said damaged flood control works be in conformity with the approved plans for flood control works on the river or water in question as contained in the report of survey. Provided further, that if there be no approved report of survey as provided for in Section 5 of this Act, then the reconstruction, repair or maintenance of damaged or impaired flood control works shall be limited to that necessary to restore the damaged or impaired flood control works to their original sections or designs and no change of location or alignment shall be made other than that necessary to protect the said flood control works from caving banks, to avoid unsatisfactory foundation conditions, and to afford the area the same protection as existed prior to the damage.