The governing body of any city annexing land pursuant to Kan. Stat. Ann. §§ 12-520 or 12-521, and amendments thereto, may enter into contractual agreements with the owners of land proposed to be annexed to guarantee the apportionment of the costs of improvements made in the area to be annexed between the city at large and the area to be annexed. The term of such agreements shall not exceed 10 years. In the event the city apportions the costs of improvements in a manner contrary to the contractual agreement, the owners of land may bring an action in the district court for deannexation, such action shall be subject to the provisions of Kan. Stat. Ann. § 12-533.

This section shall not preclude the formation of a benefit district to make such improvements upon petition by landowners in the area to be annexed.