(a) The provisions of this subchapter shall apply to:
(1) any district not participating with the United States in a navigation project; or
(2) a district participating with the United States in a navigation project if the commission by resolution adopts:
(A) this subchapter; or
(B) sections of this subchapter under which the district will operate.
(b) For the purposes of Subsection (a)(2), a district that contracts with the United States for a navigation project under Subchapter F is considered to be participating with the United States in a navigation project while the contract is in effect.