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In September 2021, the Third District Court of Appeal in Sierra Watch v. Placer County(Cal. Jan. 19, 2022) reversed a judgement upholding Placer County’s Environmental Impact Report (EIR) for a resort development project in the Olympic (formerly Squaw) Valley area. In the published portion of the opinion, the court found errors in the EIR’s description of the environmental setting and related water and air quality impact analyses, as well as in the EIR’s analysis and mitigation for construction noise impacts.

The proposed resort project is located within the Olympic Valley area, the site of the 1960 winter Olympics, a few miles northwest of Lake Tahoe. The proposed project includes two components to be built over 25 years. First, an 85-acre parcel called the Village, which would include lodging units, commercial space, and parking. Second, an 8.8-acre parcel called the East Parcel, which would primarily encompass employee housing.

In 2016, Sierra Watch filed a petition for writ of mandate challenging the project’s EIR under the California Environmental Quality Act (CEQA) on multiple grounds. Following a hearing, the trial court rejected all of Sierra Watch’s claims and Sierra Watch appealed. The court of appeal reversed and found several errors with Placer County’s CEQA analysis.

Environmental Setting

As a threshold matter, the court of appeal found the EIR’s description of the environmental setting inadequate because it did not meaningfully address the Lake Tahoe Basin. In an EIR, the environmental setting is used as the baseline against which predicted effects of the project can be described and quantified. Usually an environmental setting describes the project’s immediate vicinity, but the CEQA Guidelines provide that the description should also place a special emphasis on “environmental resources that are rare or unique to that region and would be affected by the project.”

Although all parties agreed that Lake Tahoe is a unique and significant environmental resource that would be affected by the project, the draft EIR’s environmental setting description only had one parenthetical reference to Lake Tahoe. The draft and final EIR did not discuss the importance of Lake Tahoe, its characteristics, or its current condition. The analysis largely appeared to presume that Lake Tahoe needed no introduction, and so little needed to be said about it. Thus, the court found that the EIR failed to meaningfully discuss Lake Tahoe in its description of the environmental setting.

Specifically, the Court of Appeal took issue with the EIR’s discussion of water quality impacts on Lake Tahoe. The final EIR offered some figures about current and anticipated increase in vehicle miles traveled (VMT) around Lake Tahoe, but it never clearly explained how these figures related to the lake. Only after the final EIR was prepared, the County acknowledged that “VMT and its related effects – tailpipe emissions and crushed abrasives – have a direct role in lake clarity.” Since this was not disclosed in the EIR, the court found the public did not have a meaningful opportunity to evaluate the relevance of the increased VMT to Lake Tahoe, which rendered the EIR inadequate.

Additionally, the court found error in the EIR’s discussion of the project’s impacts on Lake Tahoe and the basin’s air quality. The EIR described several different VMT thresholds of significance Tahoe Regional Planning Agency (TRPA) has used when evaluating project-level impacts. However, rather than follow one of TRPA’s approaches, the EIR simply declared that TRPA standards were inapplicable without explanation. The court found this discussion inadequate because the EIR needed to determine whether the project’s impact on Lake Tahoe and the basin were potentially significant.

Construction Noise Impacts

In the final section of the published opinion, the court finds the EIR’s analysis and mitigation of construction noise impacts inadequate. Essentially, the EIR neglected to analyze the full geographic scope of noise impacts because it only evaluated impacts to sensitive receptors within a radius of 50 feet from expected construction activity, without explanation.

The court also found that one of the mitigation measures for noise impacts was too vague. The mitigation measure required operations and techniques to be “be replaced with quieter procedures (e.g., using welding instead of riveting, mixing concrete off-site instead of on-site) where feasible and consistent with building codes and other applicable laws and regulations.” While the example measures highlighted in the EIR were relatively specific, the mitigation itself was otherwise unspecific and undefined.


Sierra Watch v. Placer County highlights the importance of recognizing a project’s impacts on unique regional resources, like Lake Tahoe, when preparing and EIR. Of particular note, the court applied and expanded the relatively new and untested VMT approach to traffic analysis in implicating other impact areas in need of attention. Practitioners might expect a project’s impacts to VMT to result in complaints well beyond simple trip generation. The court’s analysis of construction noise impacts is also a reminder that mitigation measures cannot be so vague as to defer formulation of mitigation to a later date without specific guidance or standards.