Any license heretofore granted by the State of Alabama, either expressly or by implication permitting the upland owner to occupy any part of the space between the high-water mark and the low-water mark of any navigable waterway of this state or along the banks of any river, stream or waterway now or hereafter along the waterway of this state, may be revoked by the State Docks Department whenever the department shall determine to make use of such property for purposes contemplated by this article or may be suspended pending investigation and decision as to whether such use shall be made; provided, that when such property has been or shall have been already improved by the upland owner, his license to maintain the improvement and to exercise such control thereover as may be conferred upon him by a license from the state shall not be revoked or suspended otherwise than by exercise of eminent domain as long as such owner shall occupy such property with improvements appropriate to and devoted to the use of such property as a facility to commerce as contemplated by the license. Whenever the State Docks Department shall determine that any part of the property of the state 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 it is desirable that this land should be improved by the State Docks Department, then the State Docks Department may call upon such owner of the 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. If the owner shall fail to comply with such request within a reasonable time, then the State Docks Department may file a complaint in the circuit court of the circuit in which the land is situated for the cancellation of such license. If, upon final hearing, it shall be determined by the court that said property is being occupied in violation of the intent and purpose of the license, then the court shall by its judgment cancel the same, and the State Docks Department shall be entitled to proceed with the improvement thereof; provided, that the use of such improvement by the upland owner shall in no event be disturbed until the State Docks Department is ready to begin the improvement of the land so occupied thereby under the terms of this article.