Tex. Utilities Code § 37.101

(a) If an area is or will be included within a municipality as the result of annexation, incorporation, or another reason, each electric utility and each electric cooperative that holds or is entitled to hold a certificate under this title to provide service or operate a facility in the area before the inclusion has the right to continue to provide the service or operate the facility and extend service within the utility's or cooperative's certificated area in the annexed or incorporated area under the rights granted by the certificate and this title.

(b) Notwithstanding any other law, an electric utility has the right to:

(1) continue and extend service within the utility's certificated area; and

(2) use roads, streets, highways, alleys, and public property to furnish retail electric utility service.

(c) The governing body of a municipality may require an electric utility to relocate the utility's facility at the utility's expense to permit the widening or straightening of a street by:

(1) giving the electric utility 30 days' notice; and

(2) specifying the new location for the facility along the right-of-way of the street.

(d) This section does not:

(1) limit the power of a city, town, or village to incorporate or of a municipality to extend its boundaries by annexation; or

(2) prohibit a municipality from levying a tax or other special charge for the use of the streets as authorized by Section 182.025, Tax Code.