A parks, trails, and greenways district may be created, incorporated, and managed pursuant to sections 67.5000 to 67.5038 and once created may exercise the powers given to that district pursuant to section 67.5006. A district shall include a county with a charter form of government and with more than six hundred thousand but fewer than seven hundred thousand inhabitants. Any recreation system or public parks system that exists within a district established pursuant to sections 67.5000 to 67.5038 shall remain in existence with the same powers and responsibilities it had prior to the establishment of such district. Nothing in sections 67.5000 to 67.5038 shall be construed in any manner to limit or prohibit:

(1) Later establishment or cessation of any park or recreation system provided by law; or

(2) Any powers and responsibilities of any park or recreation system provided by state law.