How Much Uncertainty Does CEQA Allow? Court Upholds EIR's Practical Approach for Evaluating Uncertain Cumulative Impacts, but Invalidates Biological Mitigation and Water Supply Analysis as Too Uncertain

by Perkins Coie

In Preserve Wild Santee v. City of Santee, the court immersed itself in an EIR’s evaluation of the impacts of a large residential project proposing 1,395 homes and 1,400 acres of open space preserve. The court upheld the analysis of cumulative impacts to biological resources despite the uncertainty regarding the extent of those impacts, but struck down project-level mitigation and an analysis of water supply impacts as too uncertain.

The City’s Practical Approach for Addressing Unknown Cumulative Impacts Was Adequate.  The EIR acknowledged that because proposed development in the surrounding area was in the early planning stages, the cumulative biological impacts were unknown.  But it explained that the area is covered by a multi-jurisdiction Multiple Species Conservation Program that is designed to protect natural habitats.  Neighboring jurisdictions had adopted subarea plans to implement the Conservation Program, but Santee had completed only a draft subarea plan.  The EIR assumed that projects in nearby jurisdictions would be consistent with the applicable subarea plans, and that projects within Santee would be governed either by its own subarea plan (if completed in time) or the overarching standards of the Conservation Program.  The EIR concluded that the project would not make a cumulatively considerable contribution to biological impacts (except concerning one species that was not covered by the Conservation Program, which the EIR addressed separately).

In upholding this conclusion, the court explained that each development project would be required to do its part to meet the goals of the Conservation Program, thus implementing its share of mitigation designed to alleviate the cumulative impact.  The EIR was not required to address each species individually, as there was insufficient information to do so.  The EIR’s discussion was adequate "under a practicable and reasonable standard."

Mitigation That Relied on a Management Plan to Be Drafted Later Was Too UncertainThe court reached a different conclusion regarding the mitigation the EIR proposed to address the project's impact to the Quino checkerspot butterfly.  The mitigation measure called for an open space preserve that would be governed by a habitat plan that was to be approved by the city and the wildlife agencies.  The court emphasized the lack of standards for actively managing the butterfly within the preserve.  The EIR failed to explain why it could not specify performance standards or guidelines and “the fact that the City and wildlife agencies must ultimately approve the plan does not cure these informational defects.”  In addition, because the timing and details for implementing the plan were left to the discretion of the preserve manager based on prevailing environmental conditions, there was no guarantee that any of the measures would occur "at any particular time or in any particular manner." 

The Water Supply Analysis Failed to Acknowledge the Uncertainty of Providing Water to the ProjectThe court also struck down the EIR's water supply analysis, in part because it failed to consider the uncertainty of obtaining supplies from the State Water Project.  The project proposed to obtain water from a local district, which would obtain water from other agencies that ultimately relied upon the State Water Project.  The local water district prepared a water supply assessment for the project that concluded that if the agencies implemented their planned water development, delivery and conservation projects, adequate supplies would be available to serve the project.  The EIR relied on that conclusion in finding water supply impacts less than significant.

The court found three problems with this analysis.  First, the EIR projected a demand of approximately 1,446 acre feet per year, while the assessment projected 881 acre feet per year.  The EIR did not explain this discrepancy, and the court rejected the parties' attempts to explain it in their briefs.  "The question is . . . not whether the project's significant environmental effects can be clearly explained, but whether they were."

Second, the EIR failed to address the uncertainty arising from a court decision that ordered severe cutbacks in the amount of water the State Water Project could pump from the delta, in order to protect the delta smelt.  The water district had prepared its assessment before the court had issued its decision, and the district acknowledged in an addendum to the assessment that it could not "predict whether any mandatory cut backs will result from the court's ruling or what the impact of those cut backs would be."  According to the court, the analysis failed to comply with the Supreme Court's 2007 decision in the Vineyard Area Citizens case, which held that an EIR must discuss reasonably foreseeable alternatives and the impacts of those alternatives when it cannot confidently identify the project's future water sources. 

Third, the EIR did not adequately address the water supply for a proposed 10-acre lake on the project site.  The EIR specifically acknowledged a potential problem with using groundwater, requiring an alternative water source if monitoring showed that groundwater levels dropped below a certain point.  But the EIR failed to identify or study any alternative source.

Read about this and other legal developments in Perkins Coie's California Land Use & Development Law Report.

Please see our website for more information about our California Environmental, Energy, Resources & Land Use professionals:

Louise Adamson, 415.344.7036
Cecily Barclay, 415.344.7117
Marc Bruner, 415.344.7171
Marie Cooper, 415.344.7012
Matt Gray, 415.344.7082
Julie Jones, 415.344.7108
Steve Kostka, 415.344.7006
Alan Murphy, 415.344.7126
Geoff Robinson, 415.344.7174
Barbara Schussman, 415.344.7168
Chris Tom, 415.344.7047

Written by:

Perkins Coie

Perkins Coie on:

Readers' Choice 2017
Reporters on Deadline

"My best business intelligence, in one easy email…"

Your first step to building a free, personalized, morning email brief covering pertinent authors and topics on JD Supra:
Sign up using*

Already signed up? Log in here

*By using the service, you signify your acceptance of JD Supra's Privacy Policy.
Custom Email Digest
Privacy Policy (Updated: October 8, 2015):

JD Supra provides users with access to its legal industry publishing services (the "Service") through its website (the "Website") as well as through other sources. Our policies with regard to data collection and use of personal information of users of the Service, regardless of the manner in which users access the Service, and visitors to the Website are set forth in this statement ("Policy"). By using the Service, you signify your acceptance of this Policy.

Information Collection and Use by JD Supra

JD Supra collects users' names, companies, titles, e-mail address and industry. JD Supra also tracks the pages that users visit, logs IP addresses and aggregates non-personally identifiable user data and browser type. This data is gathered using cookies and other technologies.

The information and data collected is used to authenticate users and to send notifications relating to the Service, including email alerts to which users have subscribed; to manage the Service and Website, to improve the Service and to customize the user's experience. This information is also provided to the authors of the content to give them insight into their readership and help them to improve their content, so that it is most useful for our users.

JD Supra does not sell, rent or otherwise provide your details to third parties, other than to the authors of the content on JD Supra.

If you prefer not to enable cookies, you may change your browser settings to disable cookies; however, please note that rejecting cookies while visiting the Website may result in certain parts of the Website not operating correctly or as efficiently as if cookies were allowed.

Email Choice/Opt-out

Users who opt in to receive emails may choose to no longer receive e-mail updates and newsletters by selecting the "opt-out of future email" option in the email they receive from JD Supra or in their JD Supra account management screen.


JD Supra takes reasonable precautions to insure that user information is kept private. We restrict access to user information to those individuals who reasonably need access to perform their job functions, such as our third party email service, customer service personnel and technical staff. However, please note that no method of transmitting or storing data is completely secure and we cannot guarantee the security of user information. Unauthorized entry or use, hardware or software failure, and other factors may compromise the security of user information at any time.

If you have reason to believe that your interaction with us is no longer secure, you must immediately notify us of the problem by contacting us at In the unlikely event that we believe that the security of your user information in our possession or control may have been compromised, we may seek to notify you of that development and, if so, will endeavor to do so as promptly as practicable under the circumstances.

Sharing and Disclosure of Information JD Supra Collects

Except as otherwise described in this privacy statement, JD Supra will not disclose personal information to any third party unless we believe that disclosure is necessary to: (1) comply with applicable laws; (2) respond to governmental inquiries or requests; (3) comply with valid legal process; (4) protect the rights, privacy, safety or property of JD Supra, users of the Service, Website visitors or the public; (5) permit us to pursue available remedies or limit the damages that we may sustain; and (6) enforce our Terms & Conditions of Use.

In the event there is a change in the corporate structure of JD Supra such as, but not limited to, merger, consolidation, sale, liquidation or transfer of substantial assets, JD Supra may, in its sole discretion, transfer, sell or assign information collected on and through the Service to one or more affiliated or unaffiliated third parties.

Links to Other Websites

This Website and the Service may contain links to other websites. The operator of such other websites may collect information about you, including through cookies or other technologies. If you are using the Service through the Website and link to another site, you will leave the Website and this Policy will not apply to your use of and activity on those other sites. We encourage you to read the legal notices posted on those sites, including their privacy policies. We shall have no responsibility or liability for your visitation to, and the data collection and use practices of, such other sites. This Policy applies solely to the information collected in connection with your use of this Website and does not apply to any practices conducted offline or in connection with any other websites.

Changes in Our Privacy Policy

We reserve the right to change this Policy at any time. Please refer to the date at the top of this page to determine when this Policy was last revised. Any changes to our privacy policy will become effective upon posting of the revised policy on the Website. By continuing to use the Service or Website following such changes, you will be deemed to have agreed to such changes. If you do not agree with the terms of this Policy, as it may be amended from time to time, in whole or part, please do not continue using the Service or the Website.

Contacting JD Supra

If you have any questions about this privacy statement, the practices of this site, your dealings with this Web site, or if you would like to change any of the information you have provided to us, please contact us at:

- hide
*With LinkedIn, you don't need to create a separate login to manage your free JD Supra account, and we can make suggestions based on your needs and interests. We will not post anything on LinkedIn in your name. Or, sign up using your email address.