Appellate Court Clarifies Factors Upon Which A Lead Agency May Determine CEQA Mitigation Measures Infeasible

In Living Rivers Council v. State Water Resources Control Board (“Living Rivers Council“), a California court of appeal held that evidence of the low likelihood and severity of a potential indirect significant effect was permissible evidence to support a determination that  a potential mitigation measure was infeasible under CEQA.


In 2004, the State Legislature enacted Water Code section 1259.4, requiring the State Water Resources Control Board (“the Board”) to adopt principles and guidelines for maintaining instream flows in Northern California coastal streams. The Board noticed and distributed a draft “Policy for Maintaining Instream Flows in Northern California Coastal Streams” (“the Policy”) and “Substitute Environmental Document” (“the SED”) focused on measures to protect native fish populations. Appendix D of the SED was a consultant’s report (“Expert Report”), which found the Policy’s proposed restrictions on surface water diversion from streams could cause  increased diversions from other water sources such as groundwater. Appendix D estimated the demand for future diversions and the indirect environmental impacts of such diversions. At the Board’s request, the Expert Report also included maps delineating subterranean streams in the policy area (“Subterranean Streams Delineations”), but these maps were not included in the Board’s disclosures. The Board adopted the Policy and the SED on May 4, 2010.

Living Rivers Council (“Living Rivers”) challenged the Policy based on alleged CEQA violations. The trial court found the SED deficient because it did not include the Subterranean Streams Delineations as a potential mitigating measure in anticipation of increased use of groundwater pumping, and did not present sufficient information to enable the public to understand the full legal options facing the board to mitigate the expected increase in the use of groundwater. Accordingly, the trial court ordered the Board to vacate its approval of the Policy and remanded the issue to the Board for reconsideration consistent with its opinion.

The Board subsequently published a Revised Substitute Environmental Document (“RSED”). It concluded that increased groundwater pumping was entirely speculative and unlikely, and listed a number of reasons why the SED inadequately addressed the issue. The RSED concluded that adopting the Subterranean Streams Delineations as a mitigation measure was not feasible because it would be ineffective and inefficient. The RSED was adopted by the Board in October 2013.

In March 2014, Living Rivers filed a petition for writ of mandate, alleging a CEQA violation based on conflicting signals given by the RSED because of the Board’s previous estimated environmental impact. Living Rivers also contended that the decision not to adopt the Subterranean Streams Delineations as a mitigation measure was based on an impermissible rationale. The trial court denied the petition and this appeal followed.

Court’s Decision

The Court of Appeal (“Court”) affirmed the trial court’s ruling. The Court first found that the 2013 RSED was not misleading because it sufficiently explained in detail why the 2010 SED was misleading. The RSED fulfilled its informational purpose on the subject of groundwater pumping as a potential significant effect by revising and clarifying certain conclusions made in the SED, and each change was internally consistent. A stakeholder wishing to comment would have understood from the RSED that while groundwater diversions could result, they were unlikely given the information available.

The Court also found the RSED’s description of the Subterranean Streams Delineations to be sufficient for the purposes of public comment, and accepted the Board’s rationale for concluding that it was an infeasible mitigating measure. The Court emphasized that the definition of “feasible” in legislation allowed the Board to consider the likelihood and severity of groundwater pumping in its determination. The Board reasoned that since groundwater pumping was unlikely to occur, the measures advocated by the Subterranean Streams Delineation were also unlikely to be effective in achieving their goal of protecting the environment. The Court found this reasoning to be sound. Moreover, the likelihood and severity of groundwater pumping as a result of the Policy is relevant to whether a mitigation measure is desirable to pursue when balanced against its costs and difficulty of implementation.

What This Means for Public Agencies

The core of the Court’s ruling further details the kinds of factors public agencies can and should consider when determining whether a particular proposed mitigation measure is “feasible” for purposes of CEQA. As a result of this ruling, public agencies considering the feasibility of potential mitigation measures may use the likelihood and severity of the potential impact in their determinations of whether certain mitigation measures are infeasible. If you have any questions about this legal development, please contact the following from our office, or the attorney with whom you normally consult.

Mona Ebrahimi | 916.321.4597

Hanspeter Walter
h | 916.321.4535