(a) The district is composed of the territory described by Section 3, Chapter 472, Acts of the 69th Legislature, Regular Session, 1985, as that territory may have been modified under:
(1) Section 7806.103 of this chapter or its predecessor statute, former Section 14, Chapter 472, Acts of the 69th Legislature, Regular Session, 1985;
(2) Subchapter J, Chapter 49, Water Code; or
(3) other law.
(b) The boundaries of the district form a closure. A mistake in the description of the district's boundaries does not affect:
(1) the district's organization, existence, or validity; or
(2) the exercise of a power, function, or purpose under this chapter.