Ala. Code § 11-47-15

The council or other governing body of any town or city may alter and change the channel of any watercourse in the police jurisdiction of the city or town and may construct and maintain wharves and construct buildings and other improvements on and near wharves and wharf sites and may collect wharfage dues and other charges thereon and rentals with respect thereto. Said council or other governing body may lease to others all or any part of wharves or sites for wharves constructed, maintained, or owned by such town or city and any buildings and other improvements so constructed on or near any wharf or wharf site for public or private use for a period or periods not exceeding 40 years from the completion of such construction or for a period or periods not exceeding 40 years from the delivery of the lease if such construction shall have been completed before the date of delivery of the lease, and may authorize the lessees in such leases and their sublessees to construct or maintain buildings and other improvements upon the properties so leased and collect wharfage due thereon and to sublet all or any part of said wharves, buildings and other improvements.