Tex. Local Government Code § 43.055: MAXIMUM AMOUNT OF ANNEXATION EACH YEAR.

(a) In a calendar year, a municipality may not annex a total area greater than 10 percent of the incorporated area of the municipality as of January 1 of that year, plus any amount of area carried over to that year under Subsection (b). In determining the total area annexed in a calendar year, an area annexed for limited purposes is included, but an annexed area is not included if it is:

(1) annexed at the request of a majority of the qualified voters of the area and the owners of at least 50 percent of the land in the area;

(2) owned by the municipality, a county, the state, or the federal government and used for a public purpose;

(3) annexed at the request of at least a majority of the qualified voters of the area; or

(4) annexed at the request of the owners of the area.

(b) If a municipality fails to annex in a calendar year the entire 10 percent amount permitted under Subsection (a), the municipality may carry over the unused allocation for use in subsequent calendar years.

(c) A municipality carrying over an allocation may not annex in a calendar year a total area greater than 30 percent of the incorporated area of the municipality as of January 1 of that year.

Acts 1987, 70th Leg., ch. 149, Sec. 1, eff. Sept. 1, 1987. Amended by Acts 1989, 71st Leg., ch. 1, Sec. 3(e), eff. Aug. 28, 1989.