Notwithstanding any other provision of this Act, the District may not regulate the operation, conduct, or navigation of any riverboat gambling casino licensed under the Illinois Gambling Act, and the District may not license, tax, or otherwise levy any assessment of any kind on any riverboat gambling casino licensed under the Illinois Gambling Act. The General Assembly declares that the powers to regulate the operation, conduct, and navigation of riverboat gambling casinos and to license, tax, and levy assessments upon riverboat gambling casinos are exclusive powers of the State of Illinois and the Illinois Gaming Board as provided in the Illinois Gambling Act.