(a) When any county has adopted planned residential development provisions in accordance with the terms of this article, a certified copy of such provisions shall be sent to every municipality within the county. All amendments shall also be sent to the aforementioned municipalities.

(b) The powers of governing bodies of counties to enact, amend and repeal planned residential development provisions shall not supersede any local planned residential development, zoning or subdivision and land development ordinance which is already in effect or subsequently becomes effective in any municipality within such county, provided that a certified copy of such provision is filed with the county planning agency, if one exists. However, all applications for tentative approval of planned residential development of land located within a municipality having adopted planned residential development provisions as set forth in this article shall nevertheless be referred to the county planning agency, if one exists, for study and recommendation and such county planning agency shall be required to report to such municipality within 30 days or forfeit the right to review.