(a) This section applies to a regional water authority that:
(1) was established after January 1, 1999;
(2) is located entirely within a county with a population greater than 3.4 million according to the 2000 federal decennial census; and
(3) has a population greater than 375,000 according to the 2000 federal decennial census.
(b) Notwithstanding any other law, except to the extent an authority to which this section applies agrees in writing, a municipality’s annexation of territory within the authority has no effect on the authority’s ability to assess and collect inside the territory annexed by the municipality the types of fees, rates, charges, or special assessments that the authority was assessing and collecting at the time the municipality initiated the annexation; provided, however, that the authority’s ability to assess and collect such fees, rates, charges, or special assessments shall terminate on the later to occur of (i) the date of final payment or defeasance of any bonds or other indebtedness, including any refunding bonds, that are secured by such fees, rates, charges, or special assessments or (ii) the date that the authority no longer provides services inside the annexed territory. An authority to which this section applies shall continue to provide services to the annexed territory in accordance with contracts in effect at the time of the annexation unless a written agreement between the governing body of the authority and the governing body of the municipality provides otherwise.