The Second District Court of Appeal upheld  the County of Santa Barbara’s Final Revised Environmental Impact Report for a 30-year conditional use permit (CUP) for the Diamond Rock mine project. Save Cuyama Valley v. County of Santa Barbara (2013 2d Dist., Div. 6), ___ Cal.App.4th ___, 2013 WL 541581 (filed 1/10/13, modified 2/8/13). The CUP allowed excavation of 500,000 tons of sand and gravel each year by real party Troesch Materials, Inc. from the often dry bed of the Cuyama River. Save Cuyama Valley lost its writ of mandate challenge to the EIR, and the Court of Appeal affirmed.

The main issues in the case concerned adequacy of the EIR’s analysis and mitigation of (1) the mining project’s hydrological impacts on the river, and (2) its impacts on basin-wide water usage and quality.

On the first topic, the EIR identified potential hydraulic impacts of (1) downstream channel degradation (i.e., downstream riverbed scouring due to pit sediment capture), (2) headcutting, and (3) bank erosion, but found these impacts unlikely to occur. The County relied on evidence showing channel degradation had not occurred in decades of operation of a similar mine; flood waters bearing sediment would flow over filled mine pits and fill in downstream scouring; and headcutting was unlikely due to the riverbed’s low slope and armoring effect of the large riverbed material on the upstream lip of mine pits. Citing but eschewing CEQA Guidelines Appendix G’s suggested 10 factors for assessing hydrology/water quality impacts, the EIR adopted a more tailored, project-specific threshold of significance for the above adverse impacts, considering them significant if they would (1) damage infrastructure (e.g., bridges, pipelines), (2) damage or destroy adjacent developments or structures by flooding or bank erosion, (3) disturb or destroy valuable in-channel riparian habitat, or (4) expose people to new flooding hazards.

The EIR concluded impacts were expected to be minor, and secondary impacts to infrastructure, adjacent developments or habitats unlikely, and thus concluded the project’s hydrological impacts “appear to be less than significant.” Nonetheless, it conservatively acknowledged “the inherent uncertainty of simulation models” and potential for underestimating effects, and deemed the impacts to be “potentially significant but mitigable.” It thus proposed (and County adopted as a condition of CUP approval) mitigation measure MM W-2 requiring (1) semi-annual river bottom surveys at, upstream, and downstream of the mine, (2) submission of the data to be State Office of Mine Reclamation (OMR), and to the other County agencies, for review, and (3) should “adverse hydraulic conditions [be] evident, or appear to be developing, which could result in offsite impacts,” to confer with County agencies to modify pit layout, width and/or depth to avoid the impacts.

The Court of Appeal upheld this analysis and mitigation against Save Cuyama Valley’s various challenges. It reached (among others) the following conclusions:

  • The County’s threshold of significance was proper, and did not need to be “formally adopted” under Guidelines § 15064(b) since it was project-specific and not for general use.
  • The “adverse hydraulic impacts” threshold adopted by County was clear, and unambiguous, distinct from the Appendix G factors, and properly adopted under CEQA.
  • CEQA Guidelines Appendix G’s thresholds of significance were only suggested, not presumptive or mandatory, and County was not required to explain why it didn’t use them.
  • Despite the differing expert opinions of the U.S. EPA and Save Cuyama’s experts, substantial evidence supported the EIR’s findings of hydrological impacts of minor magnitude. The EIR explained in detail why sediment deficiency does not necessarily equate to adverse impacts, and gave reasoned explanations for its conclusions.
  • The EIR was not “internally inconsistent” because of its conservative approach to hydrological impacts: “The report frankly acknowledges no present or likely impacts of any significant magnitude, but out of an abundance of caution and due to the uncertainties of predicting and quantifying these impacts, elects to treat the impacts as more significant than they currently appear to be.”
  • MM W-2 was a sufficient mitigation measure since County demonstrated a commitment to mitigation by adopting it as a condition of the CUP, the measure’s trigger properly incorporated the EIR’s definition of adverse hydraulic impacts, and the measure required compliance with SMARA; the Court cited case authority for the principle that: “A condition requiring compliance with environmental regulations is a common and reasonable mitigating measure.”
  • The performance standards MM W-2 was to meet were adequately spelled out by the definition of “adverse hydraulic conditions … which could result in offsite impacts” that Troesch was to avoid, and substantial evidence supported its effectiveness since the required measure addressed those impacts.

The Court of Appeal also upheld the EIR’s water impacts analysis as supported by substantial evidence, notwithstanding its unsupported conclusion that the mining project’s impact on water quality would not be significant. The EIR’s statement that groundwater under most conditions would be located below the maximum 90-foot mining depth, which formed the basis for the “not significant” conclusion, was “in tension with the data showing that the groundwater in nearby wells is found anywhere between 40 and 110 feet below ground, as well as other statements in the [EIR] itself recounting the underlying well data.” Nonetheless, Save Cuyama failed to show the unsupported “not significant” conclusion was a prejudicial error, as required by Public Resources Code § 21005(a) to obtain relief. Simply put, the error didn’t matter because CUP condition 64 required Troesch to ensure that no groundwater was exposed by its mining operations at whatever depth it was encountered. Thus, the EIR’s erroneous conclusion had no effect on its informational content or recommendations, and did not preclude informed decision making; therefore, there the inconsistency was not prejudicial.