The district is composed of the territory described by Section 1, Chapter 286, Acts of the 54th Legislature, Regular Session, 1955, as that territory may have been modified under:
(1) this subchapter or its predecessor statute, Section 4(a), Chapter 286, Acts of the 54th Legislature, Regular Session, 1955;
(2) Subchapter O, Chapter 51, Water Code;
(3) Subchapter J, Chapter 49, Water Code; or
(4) other law.