Sec. 8. All of the area:
(1) within the corporate boundaries of a city; and
(2) in unincorporated areas of the county to which the district has been extended;
constitutes a taxing district for levying special benefit taxes for park purposes as provided in this chapter. Area added to the district under section 5 of this chapter is considered to have received a special benefit from the park facilities of the district equal to or greater than the special taxes imposed on the area by this chapter in order to pay all or a part of the cost of the facilities.