Tex. Water Code § 60.039

(a) Except as provided by Subsection (c), the commission may lease the surface of land for not more than 50 years by the entry of an order on the minutes of the commission and the execution of a lease in the manner provided by the original order. The lease may not be extended beyond the 50-year period by renewal, extension, or otherwise.

(b) The commission or the executive director of the district, or a person authorized by the commission or the executive director, may enter into a lease for a monthly tenancy or a tenancy from month to month. The lease term may only exceed one year if:

(1) the commission enters an order on the minutes; and

(2) the execution of the lease is in the manner provided by the original order for the lease.

(c) This subsection applies only to a district that operates a port in this state that is wholly located in a county that borders the Gulf of Mexico and that is adjacent to a county that contains an international border and borders the Gulf of Mexico. The district may lease the surface of land for not more than 99 years or may extend a lease to a period not to exceed 99 years only if:

(1) the lease conveys an interest in the surface of the land for residential purposes only;

(2) at the time the lease will be entered into or extended, the district has not less than 50 leases in effect that convey an interest in the land surface for residential purposes only; and

(3) any part of the land owned by the district is subdivided into lots intended for residential use.