Section 819 - Applicability1. No provision of this article shall be construed to prohibit any local government from adopting and enforcing land use and development controls for lands, other than those owned by the state.2. Any local land use program which has been validly enacted or adopted by a municipality shall be valid and enforceable notwithstanding its not having been approved by the agency, and any new land use or development or subdivision of land shall be subject to the provisions of such local land use program and to the shoreline restrictions contained in section eight hundred six. If the agency has project review jurisdiction over any such land use or development or subdivision of land under section eight hundred nine, such land use, development or subdivision shall, in addition to its being subject to the provisions of any such local land use program, be subject to such agency jurisdiction. The project sponsor may not undertake or continue such land use, development or subdivision, however, or any part thereof, notwithstanding the granting of a permit therefor by the agency, unless such undertaking or continuance is also permitted by the municipality under and in accordance with the provisions of its local land use program.3. No provision of this article shall be deemed to prohibit any land use and development or subdivision of land existing prior to the effective date of this article, including those uses and development and subdivisions of land expressly not subject to agency review as provided in section eight hundred eleven.4. Nothing in this article shall be construed to empower the agency to acquire any interest in real property by purchase or condemnation. No right of first refusal or first option to purchase in favor of the agency, the department of environmental conservation or any other state agency shall in any way be created by this article or the land use and development plan.5. Nothing in this article shall be construed to supersede or replace or diminish in any way any regulatory or review authority of any other state agency.