(a) Any water improvement district, water control and preservation district, fresh water supply district, levee improvement district, drainage district, or navigation district, after conversion under § 51.040 of this code, may continue to exercise all necessary specific powers under any specific conditions provided by the chapter of this code under which the district was operating before conversion.
(b) At the time of making the order of conversion, the governing body shall specify in the order the specific provisions of the chapter of the code under which the district had been operating which are to be preserved and made applicable to the operations of the district after conversion into a district operating under this chapter.

(c) A reservation of a former power under Subsection (a) of this section may be made only if this chapter does not make specific provision concerning a matter necessary to the effectual operation of the converted district.
(d) In all cases in which this chapter does make specific provision, this chapter shall, after conversion, control the operations and procedure of the converted district.