Any license granted by the State of Alabama, either expressly or by implication, permitting the upland owner to occupy any part of the space between the channel of the Mobile River or the low water mark of the Mobile Bay and the high water mark, may be revoked by order of the director whenever said port authority shall determine to make use of such property for the purpose contemplated by this chapter, or may be suspended by order pending an investigation and decision as to whether or not such use shall be made; provided, however, that whenever such property has been or shall have been already improved by the upland owner, his license to maintain such improvements and to exercise such control thereover as may have been conferred upon him by a license from the state shall not be revoked or suspended otherwise than in the exercise of the right of eminent domain by condemnation proceedings as long as such owner shall occupy such property with improvements appropriate and devoted to the use of such property as a facility to commerce as is contemplated by such license. Whenever the port authority shall determine that any part of the property of the state above described is being occupied under a license from the state but that the improvements thereon are not being so maintained and used as facilities to commerce as reasonably to serve the purpose for which the license was granted and that it is desirable that this land should be improved by the port authority, then the director may call upon such owner of such improvements to put the same in such condition as reasonably to serve as such facilities to commerce within the purpose of the license under which they were erected, and if the said owner shall fail to comply within a reasonable time then the port authority may file a complaint in the circuit court of the circuit in which such land is situated for the cancellation of such license and if upon final hearing it shall be determined by the court that the said property is being occupied in violation of the intent and purpose of said license, then the court shall by its judgment cancel the same and the port authority shall then be entitled to proceed with the improvements thereof; provided further that the use of such improvement by the upland owner shall in no event be disturbed until the port authority is ready to begin the improvement of the land so occupied thereby under the terms of this chapter.