When the board has completed suitable plans, it shall adopt them as official plans and give public notice of such adoption in at least two newspapers in each county, wholly or partially within such flood control district, if so many are published therein, once a week for two consecutive weeks, which notice shall state that the official plans are on file in the office of the board. The board shall also give notice to all persons, whose property may be taken, damaged or destroyed in the completion of such plans, by registered mail to the last known post office address of the owner or reputed owner of the property. A certified copy of the completed suitable plans shall, upon their adoption, be recorded in the office of the recorder of deeds of each county, wholly or partially within a flood control district. Such recording shall be constructive notice to all owners whose property may be taken, damaged or destroyed in the completion of such plans.