As additional security for public securities issued or obligations incurred under this chapter, the municipality by the terms of the encumbrance may grant a purchaser under sale or foreclosure a franchise to operate the encumbered utility system, park, or pool for a term not to exceed 20 years from the date of purchase, subject to all laws regulating the operation of the utility system, park, or pool in force at the time of the sale or foreclosure.
Tex. Gov't. Code § 1502.053