Texas Natural Resources Code - NAT RES § 21.012. Surveys on Navigable Streams

(a) If the circumstances of the lines previously surveyed under the law will permit, land surveyed for individuals, lying on a navigable stream, shall front one-half of the square on the stream with the line running at right angles with the general course of the stream.

(b) A navigable stream may not be crossed by the lines of a survey.