(a) The board by resolution may exclude from the district land that:
(1) is inside the district but was not included in the district when the district was created; and
(2) has been subdivided into town lots and blocks, with streets or other thoroughfares dedicated to the use of the public.
(b) A map and the dedication of the land must be filed for record with the county clerk of the county in which the land is located before the board adopts the resolution to exclude the land.