The California Environmental Quality Act (CEQA) requires a lead agency, as defined, to prepare, or cause to be prepared, and certify the completion of an environmental impact report on a project that it proposes to carry out or approve that may have a significant effect on the environment or to adopt a negative declaration if it finds that the project will not have that effect. CEQA also requires a lead agency to prepare a mitigated negative declaration for a project that may have a significant effect on the environment if revisions in the project would avoid or mitigate that effect and there is no substantial evidence that the project, as revised, would have a significant effect on the environment. CEQA requires that an action or proceeding to attack, review, set aside, void, or annul specified acts or decisions of a public agency on the grounds of noncompliance with CEQA be commenced in accordance with specified timeframes. Existing law, the Subdivision Map Act, vests the authority to regulate and control the design and improvement of subdivisions in the legislative body of a local agency and sets forth procedures governing the local agency's processing, approval, conditional approval or disapproval, and filing of tentative, final, and parcel maps, and the modification thereof. The act requires an action or proceeding against a decision of a local agency taken pursuant to that act to be commenced within a certain time period, as specified. This bill would prohibit an action or proceeding to enforce the Subdivision Map Act from being maintained if certain criteria exist, including that the action or proceeding to enforce the Subdivision Map Act includes substantially similar claims or issues to claims or issues raised in an action or proceeding to enforce CEQA and the defendant in the action or proceeding to enforce the Subdivision Map Act was the defendant in the action or proceeding to enforce CEQA. The bill would provide that its provisions do not prohibit or abrogate specified actions, including the filing of timely objections to an agency's return to a writ seeking to enforce its specific mandates or timely filing of a separate action relating to the same project, as specified. The bill would repeal these provisions on January 1, 2032.