(a) A district may not issue bonds unless approved by the commissioners court of the county that created the district. Bonds may not be issued unless approved by a majority of the voters of the district voting in an election held for that purpose. A bond election under this subsection does not affect prior bond issuances and is not required for refunding bond issuances.
(b) A district may not issue a negotiable promissory note or notes unless approved by the commissioners court of the county that created the district.

(c) If the commissioners court grants approval under this section, bonds, notes, and other district obligations may be secured by district revenue or any type of district taxes or assessments, or any combination of taxes and revenue pledged to the payment of bonds.