Texas Local Government Code - LOC GOV'T § 43.0691. Authority to Annex

(1) the municipality holds an election in the area proposed to be annexed at which the qualified voters of the area may vote on the question of the annexation and a majority of the votes received at the election approve the annexation; and

(2) if the registered voters of the area do not own more than 50 percent of the land in the area, the municipality obtains consent to annex the area through a petition signed by more than 50 percent of the owners of land in the area.