Lake Tahoe WaterIn Sierra Club v. Tahoe Regional Planning Agency, the Ninth Circuit affirmed the district court’s summary judgment in favor of the Tahoe Regional Planning Agency (“TRPA”), finding that the TRPA’s final Environmental Impact Statement (“EIS”) for the agency’s Regional Plan Update (“RPU”) sufficiently addressed localized impacts on soil erosion and water quality. The 2012 RPU, among other things, restricted future development to areas that are already developed, and limited the extent of development in those areas. Plaintiffs, Sierra Club and Friends of the West Shore, challenged the RPU’s EIS, principally arguing that the RPU failed to adequately address the localized effects of the runoff created by the plan’s permitted development, and that the RPU improperly assumed that Best Management Practices (“BMPs”) would reduce water quality impacts of concentrated development.

Initially, the RPU was a requirement of a Congress-approved Regional Planning Compact (“Compact”) between California and Nevada. First approved in 1969, the Compact created the TRPA to serve as a bi-state land use and environmental resource planning agency for the Lake Tahoe Region, in response to the rapidly degrading clarity of Lake Tahoe. In 1980, responding to concerns that the 1969 Compact was “not sufficiently anti-growth,” Congress approved Compact amendments that required TRPA to adopt a Regional Plan and barred any development exceeding environmental threshold carrying capacities.

The 2012 RPU proposed to concentrate new and existing development into “community centers” and encouraged concentrated development by allowing the TRPA, or local governments through the use of “Area Plans,” to raise density, height, and coverage limits (i.e., coverage of land with impervious materials) in community centers. Area Plans, which would be adopted later, were to determine the precise nature of the development; and BMPs—described as “practices that reduce or prevent pollutants of concern” from entering surface and ground water—would be implemented and enforced to control potential increases in stormwater runoff and pollutant loading.

Plaintiffs alleged that the final EIS violated the Compact’s article VII (a)(2)(A)—a NEPA-equivalent requirement—by: (1) failing to take a “hard look” at impacts to water quality and soil conservation in the localized “community center” areas where concentrated development was directed, and (2) failing to adequately analyze whether the BMPs would reduce water quality impacts of concentrated development, based in part on an allegation that TRPA had a poor track record with enforcing BMPs. However, under the Compact’s “arbitrary and capricious” standard of review, the Ninth Circuit rejected the challenge.

Regarding water quality, the Ninth Circuit held that the Pollutant Load Reduction Model (“PLRM”)—a stormwater modeling simulation used to estimate localized water quality impacts—adequately addressed localized effects on parts of the lake near community centers. Specifically, the PLRM incorporated data “on land use types, impervious coverage, and BMP implementation to generate estimates of fine sediment, nitrogen, and phosphorous loading and stormwater runoff” in order to “estimate relative changes in pollutant loading that could occur within community centers.” The panel also found that the final EIS adequately explained the basis for its conclusion that concentrating development in community centers would not result in more concentrated runoff. Lastly, the Court held that the final RPU adequately responded to concerns in the draft EIR regarding “coverage transfers” across “hydrologically related areas,” by maintaining the prohibition already in place; namely, under the TRPA Code and final RPU, all transferred coverage must come from the same hydrologically related area.

Next, the Ninth Circuit rejected Plaintiffs’ assertion that the final EIS failed to adequately address the effects on soil conservation. The panel held that the RPU, as a region-wide plan, was not required to include a watershed or parcel-level analysis of soil conservation impacts. The court agreed with TRPA that evaluation of coverage at a more localized scale was appropriately reserved for the Area Plan process, which would occur prior to development. Moreover, the court noted that the PLRM simulation included soil conservation components. Lastly, the court found that the TRPA acted within its discretion in its choice of scientific methodology, and that “it was not required to conduct additional scientific studies to determine an environmental threshold for conservation of soil at a local or watershed level before analyzing the impacts of region-wide coverage changes.”

Finally, the Ninth Circuit found that TRPA had provided significant assurances of future enforcement of BMP requirements, rejecting plaintiffs’ contention that because TPRA had a poor record of BMP enforcement it improperly assumed that BMPs would be effective to reduce water quality impacts of concentrated development.

Specifically, the panel found that the final EIS detailed several new requirements that would address prior short-comings on BMP enforcement. For example, several provisions in the TRPA Code and Handbook require BMP maintenance, and TRPA’s enforcement of BMP programs. The Handbook also provides that building permits will require a BMP inspection and maintenance plan as a condition of approval, and that land owners and managers will be required to keep inspection and maintenance logs. Lastly, the final EIS also stated that TRPA had received grant funding for BMP inspections, enforcement of temporary BMP maintenance during construction projects, a residential BMP maintenance video, and the issuance of BMP maintenance reminders. Based on these added measures, the court held that TRPA had reasonably relied on its plan to better implement and maintain BMPs in concluding that the RPU would have a less-than-significant effect on water quality.

For these reasons, the Ninth Circuit concluded that the environmental analysis of the effects of concentrated development did not violate Compact article VII (a)(2)(A) by failing to address significant environmental impacts of the RPU.