Senate Bill 692 applies to a river authority created by special law under Section 59, Article XVI, Texas Constitution, whose enabling statute authorizes property tax imposition, specifies a maximum tax rate, and specifies a maximum fee that the authority may pay for assessment and collection of the tax. The bill amends the Tax Code to clarify that if the county tax assessor-collector handles assessment and collection for the river authority pursuant to certain code requirements, then the fee charged for that service may not exceed the maximum specified in the river authority's enabling statute.