Tex. Local Government Code § 374.011

(a) Except as provided by Section 374.012, a municipality may not exercise a power granted under this chapter unless:

(1) the governing body of the municipality adopts a resolution that finds that a slum area or blighted area exists in the municipality and that the rehabilitation, the conservation, or the slum clearance and redevelopment of the area is necessary for the public health, safety, morals, or welfare of the residents of the municipality; and

(2) a majority of the municipality's voters voting in an election held as provided by Subsection (b) favor adoption of the resolution.

(b) Before adopting the resolution, the governing body must give notice of the proposed resolution and must hold an election on the question. The notice must be published at least twice in the newspaper officially designated by the governing body and must state that, on a date that is specified in the notice and that is after the 60th day after the date the notice is first published, the governing body will consider the question of holding an election to determine whether it should adopt the resolution. On the date specified in the notice to consider the question, the governing body may order an election on its own motion to consider the resolution. The governing body shall order an election on the question if it receives a petition during the notice period that is signed by at least five percent of the qualified voters of the municipality who own taxable real property included on the tax rolls of the municipality. If the governing body determines that it is necessary to order an election, it shall give at least 30 days' notice of the election.

(c) If a majority of the voters voting in the election are against the resolution, the governing body may not adopt it and may not propose the resolution again for a one-year period.