Stanislaus Natural Heritage Project v. County of Stanislaus

The “tiering” provisions (Pub. Resources Code, §§ 21068.5, 21093, 21094—see fn. 5, post) of the California Environmental Quality Act (Pub. Resources Code, § 21000 et seq., or CEQA) enable a public agency to avoid, under some circumstances, having to undertake a repetitious analysis of significant environmental effects of a project when those effects have previously been addressed in an earlier environmental impact report (EIR). In the case before us a public agency approved an environmental impact report for a project calling for the creation of a 29,500-acre, 5,000-residen-tial-unit destination resort and residential community without an on-site water source, but deferred any analysis of significant environmental effects of supplying that water with the understanding that any such effects would be addressed in a later EIR to be prepared after the project was approved. In the published portion of this opinion, we hold that the tiering provisions of CEQA do not exempt a public agency from the Public Resources Code section 21100, subdivision (b)(1) requirement that an EIR shall include a detailed statement setting forth “[a]ll significant effects on the environment of the…