Fla. Stat. § 153.18

As proper facilities for the furnishing of water for human consumption and fire protection and proper facilities for the treatment, purification and disposal of sewage are essential for the health of the inhabitants of the county and for its industrial and commercial development, and as the exercise of the powers conferred by this chapter to effect such purposes constitutes the performance of essential county functions, and is hereby declared to be a county purpose, and as the facilities constructed under the provisions of this chapter, constitute public property and are used for county purposes, the county shall not be required to pay any taxes or assessments upon any such facilities or any part thereof.