ANNEXATION OR ADDITION OF TERRITORY.

(a) Territory annexed or added to the district is sufficient to avoid an impairment of the security for payment of an obligation of the district if:

(1) the taxable value of the additional territory is equal to or greater than the taxable value of the excluded territory, as determined by the most recent certified county property tax rolls; and

(2) the estimated cost to provide district facilities and services to the additional territory is equal to or less than the estimated cost to provide district facilities and services to the excluded territory, as determined by the district's engineer.

(b) In addition to the requirements of Subsection (a), if the district's outstanding bonds or contract obligations are wholly or partly payable from or secured by the net revenues from the ownership or operation of the district's waterworks or sewer systems, the projected net revenues to be derived from the additional territory during the period ending on the anniversary of the date on which the territory is added must be equal to or greater than the projected net revenues that would be derived during that period from the excluded territory, as determined by the district's engineer.