On May 21, 2013, the California First District Court of Appeal certified for publicationNorth Coast Rivers Alliance v. Marin Municipal Water District, an important CEQA opinion that affirms a highly deferential interpretation of CEQA's substantial evidence standard and defers to agency decision-making on a wide range of CEQA issues.


Under CEQA, a court may only overturn an agency decision when there is a prejudicial abuse of discretion. Such abuse of discretion exists only when: (1) the agency has not proceeded in a manner required by law, or (2) the agency decision is not supported by "substantial evidence." According to the CEQA Guidelines, substantial evidence means "enough relevant information and reasonable inferences from this information that a fair argument can be made to support a conclusion, even though other conclusions might also be reached." Despite this highly deferential language, the substantial evidence standard has frequently been treated as a less deferential standard.

The North Coast Rivers Alliance case arose out of Marin Municipal Water District's certification of an environmental impact report (EIR) for a desalination plant in Marin County, a project pursued in response to a water shortage emergency in the District's service area. North Coast Rivers Alliance challenged certification of the EIR, alleging that the EIR failed to adequately analyze the project's adverse environmental consequences. The trial court found the EIR deficient on multiple grounds and set aside the approval.

The Substantial Evidence Standard

The Court of Appeal reversed in an extensive opinion, siding with the agency on each substantial evidence question raised. In each instance, the court concluded that the EIR's discussion of impacts (on aesthetics, land use, seismology, hydrology, biological resources and GHG emissions) contained adequate factual support and discussion, and that this constituted substantial evidence to support the agency conclusion. For example, while the trial court rejected the EIR's seismology analysis for insufficiently discussing earthquake liquefaction and potential health and safety impacts from structural earthquake damage, the court upheld the seismology analysis as supported by substantial evidence because the EIR included information on area-wide geologic conditions, potential for seismic hazards such as ground shaking and liquefaction, and several potential impacts associated with geology.

The court emphatically agreed with the statement from another recent First District Court of Appeal opinion that when evaluating an EIR for substantial evidence, "the issue is whether substantial evidence supports the agency's conclusions, not whether others might disagree with those conclusions."

An All-Around Deferential Approach

The court's deferential approach extended beyond when the substantial evidence standard was in play. In every instance where the trial court found the water district's CEQA process flawed, the Court of Appeal reversed and deferred to the agency:

  • The court upheld a mitigation measure obliging the agency to comply with a landscaping plan that the trial court found to be an improper deferral of mitigation.
  • The court upheld the agency's decision to deviate from the standard environmental protocol (as recommended by other agencies) for water sampling to determine biological resources impacts on the grounds that the agency's alternative method for water sampling met the substantial evidence standard.
  • The court upheld the agency's baseline description of the environmental setting for biological resources, despite that this description did not include precise information on the age and types of species found in the project area.
  • The court upheld a mitigation measure requiring monitoring and consultation with National Oceanic and Atmospheric Administration Fisheries staff, which the trial court found insufficiently specific.
  • The court upheld the agency's decision not to discuss a particular alternative (use of green energy credits to mitigate the project's energy impacts) because the agency concluded the project's energy impacts were insignificant and therefore discussion of alternatives was not required.
  • The court upheld the agency's decision not to recirculate the EIR after adding a new alternative because the alternative was neither considerably different from the alternatives in the previously circulated EIR nor feasible.


Although it is impossible to deduce trends from a single appellate opinion, this case may signal a return to a highly deferential interpretation of the substantial evidence standard, an interpretation more closely aligned with the CEQA Guidelines. CEQA litigants should see this opinion as a strong affirmation of judicial deference to agency decision-making in the CEQA context.