Property Rights Retained Even In Municipality

Texas Local Government Code Section 51.073 - The adoption or amendment of the municipality's charter does not affect any previously existing property, action, right of action, claim, or demand involving the municipality.  A right of action, claim, or demand may be asserted as fully as though the adoption or amendment of the charter had not occurred.

Texas Revised Civil Statutes Article 1178 – The adoption of any charter hereunder or any amendment thereof shall never be construed to destroy any property, action, rights of action, claims, and demands of any nature or kind whatever vested in the city under and by virtue of any charter therefore existing or otherwise accruing to the city, but all such rights of action, claims or demands shall vest in and inure to the city and to any persons asserting any such claims against the city as fully as though the said charter or amendment had not been adopted hereunder.

Texas Jur 52 § 296 – Planned unit development
An agreement governing the creation, development, and existence of a planned unit development district must be between the governing body of the municipality and the owner of the land subject to the agreement. The agreement is not effective until signed by both parties and any other person with an interest in the land, as that interest is evidenced by an instrument recorded in the deed records of the county or counties in which the land is located.