Russian Riverkeeper v. County of Sonoma

1
Filed 8/4/26
CERTIFIED FOR PUBLICATION
IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA
FIRST APPELLATE DISTRICT
DIVISION TWO
RUSSIAN RIVERKEEPER et al.,
Plaintiffs and Respondents,
v.
COUNTY OF SONOMA,
Defendant and Appellant.
A172760
(Sonoma County Super. Ct.
No. SCV-273415)
In 2023, the County of Sonoma amended its local ordinance regulating
approval of groundwater well permits. Russian Riverkeeper and California
Coastkeeper Alliance (together, Keepers) challenged the amendments in
superior court, arguing that in amending the ordinance Sonoma failed to
fulfill its duties under the public trust doctrine and also failed to comply with
the California Environmental Quality Act (Pub. Resources Code, § 21000 et
seq.; CEQA). The superior court agreed with Keepers on both points and
issued a writ of mandate, setting aside the amended ordinance. On appeal,
Sonoma asks us to reverse.
We conclude Keepers failed to satisfy their burden of showing Sonoma’s
public trust analysis was arbitrary, capricious, or entirely lacking in
evidentiary support, but we agree with the superior court that substantial
evidence does not support Sonoma’s claimed exemptions from CEQA review.
As we will discuss, the distinct burdens of proof and standards of review
applicable to each claim require this split. Therefore, we reverse the superior

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court’s determination that Sonoma violated the public trust doctrine but
affirm the court’s conclusion that Sonoma failed to comply with CEQA.
BACKGROUND
“ ‘By the law of nature these things are common to mankind—the air,
running water, the sea and consequently the shores of the sea.’ ” (National
Audubon Society v. Superior Court (1983) 33 Cal.3d 419, 433–434 (National
Audubon), quoting Institutes of Justinian 2.1.1.) The public trust doctrine
evolved from the concept that “the sovereign owns ‘all of its navigable
waterways and the lands lying beneath them “as trustee of a public trust for
the benefit of the people.” ’ ”1 (National Audubon, at p. 434.) In California,
the public trust doctrine imposes “an affirmative duty” upon the state “to
take the public trust into account in the planning and allocation of water
resources, and to protect public trust uses whenever feasible.” (Id. at p. 446.)
The events in this appeal were set in motion by a 2018 Court of Appeal
decision, which held that counties, as subdivisions of the state, share the
state’s “responsibility for administering the public trust.” (Environmental
Law Foundation v. State Water Resources Control Bd. (2018) 26 Cal.App.5th
844, 855, 868 (Environmental Law Foundation).) Specifically, the Third
District determined in Environmental Law Foundation that “the public trust
doctrine impose[d] a fiduciary duty on the County” of Siskiyou to consider the
public trust in permitting groundwater wells that impacted navigable
waterways (i.e., public trust resources). (Id. at pp. 855, 861.) To comply with
its public trust duties, Sonoma amended its well permitting ordinance;
Keepers challenge that amendment in these proceedings.
1 Navigable waters are those “which are capable of being navigated by
oar or motor-propelled small craft.” (People ex rel. Baker v. Mack (1971)
19 Cal.App.3d 1040, 1050; see also Harb. & Nav. Code, § 100 [navigable
waters defined].)

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I. Factual Background
In Sonoma, the main stem of the Russian River is considered a
navigable waterway protected by the public trust doctrine. (See Hitchings v.
Del Rio Woods Recreation & Park Dist. (1976) 55 Cal.App.3d 560, 570–571
[“the Russian River from Alexander Valley Bridge to the Del Rio Dam” is
“navigable in law”].) The Russian River also serves as a critical habitat to
threatened and endangered species like the Central California Coast Coho
salmon, the California Costal Chinook salmon, and the Central California
Coast steelhead trout (collectively, salmonids). However, “[g]roundwater
extraction has the potential to impact groundwater dependent ecosystems”
such as those of anadromous salmonids, which “require sufficient water
depths . . . in order to reach spawning areas.”
Sonoma relies on more than “45,000 water wells, the most per capita in
any county in California,” to supply water for agriculture, residential,
commercial, and industrial users in unincorporated areas. Consequently,
between 2017 and 2022, Sonoma issued an average of 320 permits for
groundwater wells each year.
Sonoma regulates the “procedures, construction standards and
setbacks, destruction, and water treatment” of groundwater wells through
Chapter 25B of the Sonoma County Code (Chapter 25B). The 2015 version of
Chapter 25B allowed Sonoma to issue groundwater well permits on a “purely
ministerial basis,” meaning permit applications were “subject to objective
codified standards, which, if met, result[ed] in permit.”2 Thus, according to a
2 In 2015, Sonoma amended Chapter 25B to comply with Water Code
section 13801, which, in relevant part, requires counties to “adopt a water
well . . . drilling and abandonment ordinance” that meets or exceeds certain
requirements. (Wat. Code, § 13801, subd. (c).) Sonoma requests we take
judicial notice of an earlier version of Chapter 25B, which purportedly

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report prepared by Sonoma, between 2015 and 2023, Chapter 25B did not
“explicitly require consideration of impacts to public trust resources for
individual well permits.”
In 2023, in response to Environmental Law Foundation and an ensuing
lawsuit by the California Coastkeeper Alliance, Sonoma amended Chapter
25B in an attempt to comply with its public trust duties.
A. The Amendment Process
The Sonoma Board of Supervisors (the Board) held its first hearing on
potential amendments to Chapter 25B on August 9, 2022. Sonoma staff
presented on the public trust doctrine and the proposed amendments, and
members of the public, including Keepers, offered comments in response.
After the hearing, the Board sought more information and directed staff to
coordinate with the relevant governmental agencies and engage in public
outreach.
In September 2022, Sonoma released a revised version of the proposed
amendments to Chapter 25B for public review and held four outreach
meetings to explain the revisions, solicit feedback, and answer questions. On
October 4, 2022, Sonoma held a noticed public hearing on the proposed
amendments. After the hearing, the Board requested more analysis and
demonstrates that Sonoma “had issued well permits on a purely ministerial
basis since 1972.” Keepers oppose the request because (1) Sonoma did not
make the request for judicial notice below, and (2) the 1972 version is not
relevant to this appeal. Because Sonoma’s groundwater well permitting
process in 1972 is not relevant to this appeal, we deny the request for judicial
notice. (See, e.g., San Francisco Baykeeper, Inc. v. State Lands Com. (2015)
242 Cal.App.4th 202, 231 (San Francisco Baykeeper) [declining request to
take judicial notice of California Coastal Commission letter as not relevant];
Roth v. Jelley (2020) 45 Cal.App.5th 655, 678, fn. 10 [declining judicial notice
request because the documents “are not relevant to the issues raised in this
appeal”].)

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directed staff “to convene a Technical Advisory Committee to advise on
proposed amendments to Chapter 25B.” The Board planned to revisit the
matter in six months (April 2023); however, to prevent “an undue rush on
well permitting” during the intervening period, the Board imposed a
temporary moratorium on new well permits from October 4, 2022, to April
2023, except for emergencies.
The Board convened a policy working group and a separate technical
working group to report on the “best available science and policies for
development of a well ordinance.” Members of the policy working group
“represent[ed], solicit[ed], and integrate[d] community and stakeholder
interests into recommendations on the revised well ordinance,” while the
technical working group “advise[d] on the analytical processes necessary to
implement any potential policies,” focusing on “technical development
through data compilation, modeling, and other measures to better
understand the interconnection of public trust surface waters and
groundwater.”
The working groups were comprised of scientific experts, public
agencies, conservation groups, and community members, and each group
considered and evaluated well classifications, monitoring and metering
requirements, adverse impacts, conservation measures, and medium- and
long-term policy options. The working groups engaged in six independent
meetings and three joint meetings between November 2022 and March 2023.
Additionally, the groups meet weekly with Matthew O’Connor, Ph.D., a
hydrologist with O’Connor Environmental, Inc., who provided technical
support services and helped working group members review and interpret
hydrological data.

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In March 2023, O’Connor issued a report, titled “Sonoma County Well
Ordinance Public Trust Review Area Delineation” (the O’Connor report). The
O’Connor report identified areas where groundwater pumping (“streamflow
depletion”) could affect navigable waters and salmonid habitats,3 which it
designated as “Public Trust Review Area” (PTRA). The PTRA was identified
using a “risk-based approach” that considered “two primary factors”:
“Significant Resource Sensitivity” and “Significant Existing Streamflow
Depletion.” Waterways within Sonoma, including non-navigable waterways,
were ranked from “low” to “high” or “very high” based on the sensitivity of the
salmonid habitats and the level of existing streamflow depletion. Areas that
ranked as “moderate risk” to “high risk” in either habitat value or streamflow
depletion were included in the PTRA, while areas that were classified as “low
risk” for both habitat value and streamflow depletion were excluded from the
PTRA. In high risk areas, the PTRA included the entire sub-watershed “to be
protective of both acute and cumulative streamflow depletion impacts.” In
moderate risk areas, the PTRA “consists of stream buffers,” which are areas
that extend anywhere from 100 feet to 750 feet from the stream based on “the
transmissivity and storativity of the aquifer and the distance of the well from
the stream.”
Also in March 2023, the working groups issued an “Outcome and
Recommendations Report” that provided “recommendations and options of
how” Sonoma could satisfy its public trust obligations that included
“[c]umulative impact considerations.” Using the PTRA framework, the
working groups recommended categorizing well permit applications by level
3 Salmonids were used as “indicator species” because they are “sensitive
to streamflow depletion” and “represent overall sensitivity of [public trust
resources].”

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of review; permits would be subject to either “ministerial (routine)” review or
“discretionary (more tailored) review” based on location and well type. Wells
outside of the PTRA would be subject to ministerial review. Wells within the
PTRA would be subject to discretionary review unless the well “fit into
defined ministerial well classes.”
The working groups also recommended two levels of water conservation
requirements that would be applicable to “[n]early all wells in the public
trust review area,” “except public water wells, which fall under local
government and/or State Water Board jurisdiction.” Additional metering and
monitoring requirements were recommended “to increase data collecting to
improve water use estimates.”
After considering the working groups’ recommendations and additional
comments from the public, the Board adopted the proposed amendments on
April 18, 2023. The Board did not conduct an independent environmental
review under CEQA because it determined the Class 7, Class 8, and the
common sense exemptions applied. (Cal. Code Regs., tit. 14,4 §§ 15307,
15308, 15061, subd. (b)(3).)
B. The Amendment of Chapter 25B5
The purpose of the amendments, as stated in Chapter 25B, “is to
protect the environment, public health and safety, and groundwater
resource[s]” and “to address the County’s public trust obligation.” (Ch. 25B,
§ 25B-2, subds. (a), (b).) As amended, Chapter 25B provides: “All water well
4 We refer to the CEQA guidelines (Cal. Code Regs., tit. 14, §§ 15000–
15387) as the Guidelines.
5 Further references and citations to Chapter 25B are to the version
amended in 2023 unless otherwise noted.

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applications shall be reviewed for potential adverse impacts on public trust
resources, except as provided in this Chapter.” (Id., § 25B-4, subd. (d)(1).)
Adopting the PTRA framework set forth in the O’Connor report,
Chapter 25B created a “Public Trust Review Area,” which it defined as “the
area estimated to be where the underlying aquifer is interconnected with
navigable surface waters or a tributary stream that flows to a navigable
water and which is based on available information indicating groundwater
extraction may impact public trust resources including instream habitat of
anadromous fish.”6 (Ch. 25B, § 25B-4, subd. (d)(2).)
Consistent with the working groups’ recommendations, Chapter 25B
created two categories of permit applications: “Discretionary” permit
applications and “Ministerial” applications. (Ch. 25B, § 25B-5, subd. (d)(1),
(2).) For discretionary permits, the applicant must provide “sufficient”
information to determine whether issuing a permit will “cause or exacerbate
a substantial adverse impact on public trust resources after imposition of
feasible mitigation measures.”7 (Id., § 25B-4, subd. (d)(3).) “Applications not
subject to the [discretionary] public trust limitation are subject to ministerial
review,” meaning the application “shall be approved” if it otherwise complies
with the Sonoma County Code. (Id., § 25B-5, subd. (e)(1), (2).)
Certain categories of wells were “exempt from the discretionary public
trust review,” and thus subject to ministerial approval, because they pose a
“low potential for impacts to public trust resources” or involve an “overriding
6 Chapter 25B includes a “map of the Public Trust Review Area,” which
may be updated “[f]rom time to time,” at the Board’s discretion. (Ch. 25B,
§ 25B-4, subd. (d)(2).) As initially adopted, the PTRA “covers 313 square
miles (19% of the County).”
7 In their briefing to us, Keepers represent that the discretionary
review process “is not at issue in this lawsuit.”

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public interest in favor of ensuring adequate water supply for existing and
domestic uses.” (Ch. 25B, § 25B- 4, subd. (e).) As relevant, these exemptions
include: (1) “water well[s] outside the Public Trust Review Area”; (2) “Low
Water Use” wells, “where the cumulative groundwater use from all wells on a
parcel” is limited to two acre-feet per year (AFY), and the well owner
complies with metering and monitoring requirements and Level 1
conservation measures8; (3) “Existing Use” wells, “where the cumulative
groundwater use from all wells on the parcel” is limited to amounts
historically used as of October 4, 2022 (the start of the mortarium), provided
the owner complies with metering and monitoring requirements and Level 1
and 2 conservation measures9; and (4) “Net Zero Groundwater Increase”
wells, “where the proposed use of water may increase but not result in a net
increase in groundwater use from the local aquifer through implementation
of water conservation measures . . . or participation in a streamflow
augmentation project authorized by the California Department of Fish and
Wildlife or National Marine Fisheries Service, provided that” the well
complies with metering and monitoring requirements and Level 1 and 2
8 Level 1 water conservation requirements include efficient faucets and
showerheads; leak and water conservation audits; water efficient
landscaping; a limit on “irrigated grass lawns”; disconnection of downspouts
and redirection of roof rainwater to a location that “maximized infiltration
and minimizes erosion”; and compliance with applicable water conservation
requirements “that are consistent with or more protective than the
requirements of this Chapter.” (Ch. 25B, § 25B-13, subd. (b).)
9 Level 2 water conservation requirements include efficient water
closets and urinals; a water conservation plan “to reduce groundwater use to
the maximum extent feasible” for commercial, industrial, and institutional
sites; a conservation plan and “a frost protection plan” for agricultural sites
using greater than two AFY of water; and “growing season” use limits for
vineyards. (Ch. 25B, § 25B-13, subd. (a).)

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conservation requirements, and the applicant demonstrates through a
hydrogeologist prepared “groundwater recharge plan and report” that
“enhanced ground water recharge” fully offsets “the proposed net increase in
water extraction.” (Ch. 25B, § 25B-4, subd. (e)(2), (6)–(8).)
To comply with the meeting and monitoring requirements, well owners
were required to install, maintain, and report to Sonoma’s “Permit and
Resource Management Department” monthly readings from “totalizing water
meters” that “measure[d] all groundwater extracted from the well,” and
monitor and report on “water levels within the well . . . at least monthly.”10
(Ch. 25B, §§ 25B-5, subd. (a); 25B-12, subd. (a).) Sonoma “anticipated” and
“expected” that net groundwater use by existing users would decrease over
time through the implementation of Level 1 and Level 2 conservation efforts
but could not “quantify” any water savings due to “uncertainty” in its
estimates.
Under the amended Chapter 25B, Sonoma retained the right to inspect
well sites before and after permit issuance, to deny noncompliant
applications, and to revoke or modify permits if “circumstances under which
the permit was granted have changed and the public health, safety, and
welfare require” or if the permitted work violated applicable ordinances.
(Ch. 25B, §§ 25B-5, subd. (e)(7); 25B-10, subd. (d).) “Any interested person”
could appeal the discretionary approval or rejection of a well application to
the Board, which, if requested by the permitting agency, could approve a
10 Certain wells were exempt from the metering and monitoring
requirements. Wells that serviced a single parcel of land for solely
residential purposes with a cumulative groundwater use of two acre-feet per
year (AFY) or less of water were exempt from both the metering and
monitoring requirements. (Ch. 25B, § 25B-12.) Wells with a “cumulative
groundwater use of 5.0 acre-feet or less of water per year” were exempted
from only the monitoring requirement. (Id., § 25B-12, subd. (b).)

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permit where the “overriding considerations that balance the protection of
public trust resources with the health, safety and welfare needs of the
community, including the need for drinking water” warranted. (Id., § 25B-4,
subd. (d)(6), (7).)
II. Procedural Background
In May 2023, Keepers filed a petition for writ of mandate and
declaratory and injunctive relief, seeking to invalidate the amended
ordinance and enjoin Sonoma from issuing groundwater well permits. In
August 2024, after briefing and a hearing on the merits, the superior court
granted the petition in full. Specifically, the court found that the Keepers
satisfied their burden of showing the amendments lacked evidence in support
of the public trust because “there is no evidence or analysis supporting the
Amendment and that such evidence or analysis is necessary in order to
determine the efficacy of the Amendment’s terms as well as what is feasible.”
The court further found that Sonoma failed to support its finding that the
amended ordinance was exempt from CEQA review.
On October 30, 2024, the court entered judgment, setting aside the
amendments to Chapter 25B, rescinding the categorical exemptions to CEQA
review, and suspending the issuance of non-emergency well permits “unless
and until [Sonoma] has complied with the requirements of the Public Trust
Doctrine.” Sonoma filed a notice of intent and motion for new trial, which the
court denied.
Sonoma filed a timely notice of appeal from the October 2024 judgment.
DISCUSSION
On appeal, Sonoma asserts three grounds for reversal. With regard to
the public trust doctrine, Sonoma argues that we should “decline to follow”
Environmental Law Foundation and reverse judgment because Keepers did

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not satisfy their burden of proof in challenging the amended ordinance.
Regarding CEQA, Sonoma claims that substantial evidence supports its
determination that the amended ordinance is exempt from review and
Keepers failed to demonstrate otherwise. Lastly, Sonoma argues the
judgment must be reversed because it is procedurally and substantively
defective.11
I. Public Trust Doctrine
“The public trust doctrine has been part of California law since the
state’s admission to the Union in 1850.” (World Business Academy v.
California State Lands Com. (2018) 24 Cal.App.5th 476, 508 (World Business
Academy); see also Pub. Resources Code, § 6009, subd. (a) [“California
received title to the tidelands, submerged lands, and beds of navigable lakes
and rivers . . . subject to the public trust”].) While initially dedicated to
tidelands and navigable waters, the public trust doctrine now “extends to
nontidal bodies such as inland waterways and lakes, the lands beneath them,
as well as any streams and tributaries that affect any navigable waters.”
(Personal Watercraft Coalition v. Marin County Bd. of Supervisors (2002)
100 Cal.App.4th 129, 144 (Personal Watercraft).) Under the doctrine, the
11 We granted leave for five amici curiae to submit briefs in support of
the parties. In support of Sonoma, California Water Agencies and California
State Association of Counties filed briefs generally arguing we should not
follow Environmental Law Foundation. In support of Keepers,
Environmental Law Foundation and California Law Professors argue in favor
of following Environmental Law Foundation; California Law Professors also
“explain[ ] the relevant legal standards” for reviewing compliance with the
public trust doctrine but does not take a position on “whether [Sonoma]
satisfied this duty.” Each party submitted a consolidated brief in response to
these amici. Additionally, Endangered Habitats League filed a brief in
support of Keepers, arguing Sonoma failed to comply with CEQA, to which
Sonoma responded in a separate brief.

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state owns public trust resources “ ‘as trustee for public purposes’ ” and “has
an obligation to regulate the use of these lands for the general benefit of the
community.” (World Business Academy, at p. 509.)
The public trust doctrine is “more than an affirmation of state power to
use public property for public purposes.” (National Audubon, supra,
33 Cal.3d at p. 441.) It also imposes an affirmative “duty . . . to protect the
people’s common heritage” and specifically “to take the public trust into
account in the planning and allocation of water resources, and to protect
public trust uses whenever feasible.” (Id. at pp. 441, 446 [requiring public
agency to consider public trust in diverting water from streams running into
Mono Lake].)
A. Environmental Law Foundation v. State Water Resources
Control Board
In Environmental Law Foundation, the Court of Appeal answered the
“extraordinarily narrow” question of “whether the County and the Board
have common law fiduciary duties to consider the potential adverse impact of
groundwater extraction on the Scott River, a public trust resource, when
issuing well permits.” (Environmental Law Foundation, supra,
26 Cal.App.5th at pp. 851–852.) The Environmental Law Foundation court
concluded the County of Siskiyou did bear such public trust duties but
declined to “attempt to define the common law public trust duties of the
Board or the County” in “any hypothetical factual scenarios.” (Id. at p. 852.)
“Although the state as sovereign is primarily responsible for
administration of the trust,” Environmental Law Foundation held, “the
county, as a subdivision of the state, shares responsibility for administering
the public trust and ‘may not approve of destructive activities without giving
due regard to the preservation of those resources.’ ” (Environmental Law
Foundation, supra, 26 Cal.App.5th at p. 868, quoting Center for Biological

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Diversity, Inc. v. FPL Group, Inc. (2008) 166 Cal.App.4th 1349, 1370, fn. 19
(Center for Biological Diversity) [“If plaintiffs believe that the board of
supervisors or any other agency or subdivision of the state has failed to
discharge its responsibilities under the public trust, they may bring an
appropriate action against those agencies”].)
We are not persuaded by Sonoma’s argument that Environmental Law
Foundation “is flat wrong.” As Sonoma frames the issue, the state has “sole
authority to administer the public trust,” and “the only way that a county can
‘share’ in the State’s responsibility to administer the public trust is if the
Legislature expressly delegates its affirmative duty.” “Such a delegation
never occurred here,” says Sonoma, which describes Environmental Law
Foundation as “an anomaly” that we should not follow. Although not
binding, “we ordinarily follow the decisions of other districts without good
reason to disagree,” and we see no reason to disagree with Environmental
Law Foundation. (Greyhound Lines, Inc. v. County of Santa Clara (1986)
187 Cal.App.3d 480, 485.)
First, Environmental Law Foundation builds upon Center for Biological
Diversity, supra, 166 Cal.App.4th at page 1369, in which Division Three of
this appellate district explained that “plaintiffs have the right to insist that
the state, through its appropriate subdivisions and agencies, protect and
preserve public trust property.” Notably, Center for Biological Diversity
rejected the argument that Sonoma asserts in this appeal—“that the absence
of legislation explicitly delegating to the counties the responsibility for
enforcing the public trust over birdlife means that the Alameda County
Board of Supervisors cannot be held accountable for authorizing conduct
unjustifiably detrimental to these natural resources.” (Id. at p. 1370, fn. 19.)

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We disagree with Sonoma’s attempt to minimize Center for Biological
Diversity’s conclusion as dicta. The Court of Appeal affirmed the dismissal of
the public trust claim on the alternative ground that Alameda was “a
necessary and indispensable party.” (Center for Biological Diversity, supra,
166 Cal.App.4th at p. 1372.) “When an appellate court bases its decision on
alternative grounds, none is dictum.” (Greyhound Lines, Inc. v. County of
Santa Clara, supra, 187 Cal.App.3d at p. 485; McClain v. Alameda County
(1962) 209 Cal.App.2d 73, 76 [“Where two independent reasons are given for
a decision, . . . neither one is to be considered mere dictum”].)
Second, we are not persuaded by Sonoma’s legal authority purportedly
requiring a “delegation of the State’s public trust obligations.” Sonoma
claims, “California courts universally acknowledged the state as the sole
trustee of the public trust doctrine,” citing Gray v. Reclamation Dist.
No. 1500 (1917) 174 Cal. 622, 636; Colberg, Inc. v. State ex rel. Dept. of Public
Works (1967) 67 Cal.2d 408, 416; Personal Watercraft, supra, 100 Cal.App.4th
at page 145; and National Audubon, supra, 33 Cal.3d at page 424. While
these cases do recognize “[t]he supreme control of the state over its navigable
waters” (Gray, at p. 636), it is in the context of other rights (e.g., the rights of
private parties) “yield[ing] without compensation to a proper exercise of the
power of the state over its navigable waters,” which is “absolute except as
limited by the paramount supervisory power of the federal government over
navigable waters.” (Colberg, at pp. 416–417, citing Gray, at p. 637.) Thus,
the words “supreme” and “absolute” as used by Gray, at page 637, and
Colberg, at page 416, are not reasonably construed as meaning “sole” or
exclusive, as Sonoma argues. Rather, supreme and absolute are more fairly
read as meaning primary, as used in Environmental Law Foundation.
(Environmental Law Foundation, supra, 26 Cal.App.5th at p. 868 [“the state

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as sovereign is primarily responsible for administration of the trust” (italics
added)].)
Personal Watercraft, supra, 100 Cal.App.4th at page 146, also cited by
Sonoma, rejected an argument analogous to the one Sonoma asserts here. In
Personal Watercraft, plaintiffs claimed that the state’s public trust power was
“exclusive,” but the Court of Appeal clarified: “The State may be preeminent,
but it has not preempted the field to itself,” and thus the plaintiffs “failed to
persuade [the court] that the County usurped powers belonging solely to the
State.”12 (Id. at pp. 146, 153.)
Thus, Gray, Colberg, and Personal Watercraft stand for the same
proposition acknowledged by Environmental Law Foundation: “the state as
sovereign is primarily responsible for administration of the trust.”
(Environmental Law Foundation, supra, 26 Cal.App.5th at p. 868, italics
added.) We reject the idea that the state cannot share public trust duties,
because “shar[ing] responsibility for administering the public trust” (ibid.) is
different from “abdication” of public trust rights and responsibilities (Illinois
Central Railroad v. Illinois (1892) 146 U.S. 387, 452–453), or improper
“ ‘delegat[ion]’ ” of those responsibilities by placing them “ ‘entirely beyond
the direction and control of the State’ ” (National Audubon, supra, 33 Cal.3d
at p. 438).
To the contrary, and consistent with Environmental Law Foundation,
courts have recognized that “there may be circumstances in which [the public
12 Sonoma argues, on reply, that “Personal Watercraft involved the very
delegation by the Legislature to the county” that is presently missing.
However, the statute at issue in Personal Watercraft, Harbors and
Navigation Code section 660, defined the county’s ability to regulate
“ ‘vessels’ ” on its navigable waters much in the same way that Water Code
section 13801 defines Sonoma’s ability to regulate groundwater wells.
(Personal Watercraft, supra, 100 Cal.App.4th at p. 146.)

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trust] affirmative duty also belongs to other state agencies.” (Planning &
Conservation League v. Department of Water Resources (2024) 98 Cal.App.5th
726, 769, italics added.) In such circumstances, the duty “under the public
trust doctrine is triggered . . . where [the county] is taking an action with an
impact on public trust uses.” (Id. at p. 770.) Accordingly, Sonoma’s
regulation of well permits “carries with it an ‘affirmative duty to take the
public trust into account.’ ” (San Francisco Baykeeper, supra,
242 Cal.App.4th at p. 234, italics added.)
Therefore, considering California case law on the public trust doctrine,
we see no reason to depart from Environmental Law Foundation’s holding
that counties like Sonoma “share[ ] responsibility for administering the
public trust” with the state in permitting groundwater wells. (Environmental
Law Foundation, supra, 26 Cal.App.5th at pp. 867–868.)
B. Compliance with the Public Trust Doctrine
For its second argument, Sonoma asserts that Keepers did not show the
amendment of Chapter 25B was arbitrary, capricious, or entirely lacking in
evidentiary support. Considering the “deferential” standard of review and
contours of the public trust doctrine, we agree with Sonoma. (American
Coatings Assn. v. South Coast Air Quality Management Dist. (2012)
54 Cal.4th 446, 461 (American Coatings); National Audubon, supra,
33 Cal.3d at p. 446 [“As a matter of practical necessity the state may have to
approve appropriations despite foreseeable harm to public trust uses”].)
The parties dedicate large portions of their briefs to discussing the
superior court’s analysis. However, under the applicable standard of review,
we “perform the same function” as the superior court and “therefore do not
undertake a review of the [superior] court’s findings or conclusions.” (Kahn v.
Los Angeles City Employees’ Retirement System (2010) 187 Cal.App.4th 98,

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105–106.) Accordingly, our discussion begins with the appropriate standard
of review and explains why Sonoma’s amended ordinance withstands judicial
scrutiny before turning to Keepers’ arguments since Keepers bear the burden
of proof in challenging the amendments. (Id. at p. 106.)
“Code of Civil Procedure section 1085 permits judicial review of an
agency’s quasi-legislative act of adopting a regulation.” (Western States
Petroleum Assn. v. California Air Resources Board (2025) 108 Cal.App.5th
938, 957.) But to start, we must presume the legislative act is valid. (San
Francisco Tomorrow v. City and County of San Francisco (2014)
229 Cal.App.4th 498, 509 (San Francisco Tomorrow).) The legislative body
“ ‘need not make explicit findings to support its action’ ” (id. at p. 509);
instead, “to overcome the presumption of validity, the petitioner must
produce evidence ‘compelling the conclusion that the ordinance is, as a matter
of law, unreasonable and invalid.’ ” (Corona-Norco Unified School Dist. v.
City of Corona (1993) 17 Cal.App.4th 985, 993 (Corona-Norco).)
As the parties agree, “ ‘it is petitioner’s burden to establish that [the
county’s] decision was arbitrary, capricious, entirely lacking in evidentiary
support, unlawful, or procedurally unfair.’ ” (American Coatings, supra,
54 Cal.4th at p. 460, italics added.) Importantly, this “entirely lacking”
standard of review “ ‘is not the same as a substantial evidence test’ ”; it “is
more deferential to agency decisionmaking than the substantial evidence
standard.” (Id. at p. 461.) Indeed, review of “quasi-legislative acts are
accorded the most deferential level of judicial scrutiny.” (Pulaski v.
Occupational Safety & Health Stds. Bd. (1999) 75 Cal.App.4th 1315, 1331,
citing Western States Petroleum Assn. v. Superior Court (1995) 9 Cal.4th 559,
575–576; see also Carrancho v. California Air Resources Board (2003)
111 Cal.App.4th 1255, 1266 [legislative acts entitled to deference include

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“investigation and information gathering in aid of, or as a basis for,
prospective legislation”].)
“Courts exercise limited review ‘out of deference to the separation of
powers between the Legislature and the judiciary.’ ” (Carrancho v. California
Air Resources Board, supra, 111 Cal.App.4th at p. 1265, quoting California
Hotel & Motel Assn. v. Industrial Welfare Com. (1979) 25 Cal.3d 200, 212.)
Accordingly, courts “ ‘cannot inquire into the wisdom of a legislative act or
review the merits of a local government’s policy decisions.’ ” (San Francisco
Tomorrow, supra, 229 Cal.App.4th at p. 509.) “If the record reflects ‘ “a
reasonable basis for the action of the legislative body, and if the
reasonableness of the decision is fairly debatable,” ’ ” then a reviewing court
will not disturb the legislative determination. (Fair Education Santa
Barbara v. Santa Barbara Unified School District (2021) 72 Cal.App.5th 884,
895.) And, unless it is entirely lacking in evidentiary support, we will uphold
a legislative act regardless of whether “there is evidence, even substantial
evidence, supporting” an alternative decision. (American Coatings, supra,
54 Cal.4th at p. 475.)
In the public trust context, we have said there must be “ ‘full
consideration of the state’s public interest’ ” in any “ ‘action which will
adversely affect traditional public rights in trust lands.’ ” (Zack’s, Inc. v. City
of Sausalito (2008) 165 Cal.App.4th 1163, 1189.) However, “the concept of a
public use is flexible, accommodating changing public needs”; thus, there is
“no set ‘procedural matrix’ for determining” compliance with the doctrine.
(San Francisco Baykeeper, supra, 242 Cal.App.4th at pp. 233–234.) “Indeed,
imposing such procedural constraints would be inconsistent with the
recognition that the state is free to choose between public trust uses” and
“selecting one trust use ‘in preference to . . . [an]other cannot reasonably be

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said to be an abuse of discretion.’ ” (Citizens for East Shore Parks v. State
Lands Com. (2011) 202 Cal.App.4th 549, 577, quoting Higgins v. City of
Santa Monica (1964) 62 Cal.2d 24, 30.)
As our Supreme Court recognized in 1983, “[t]he population and
economy of this state depend upon the appropriation of vast quantities of
water for uses unrelated to in-stream trust values,” and “[a]s a matter of
practical necessity[,] the state may have to approve appropriations despite
foreseeable harm to public trust uses.” (National Audubon, supra, 33 Cal.3d
at p. 446.) “The public trust resources therefore need not be protected under
every conceivable circumstance, but only in those where protection or harm
minimization is feasible.” (Monterey Coastkeeper v. California Regional
Water Quality Control Bd., etc. (2022) 76 Cal.App.5th 1, 21 (Monterey
Coastkeeper).) Accordingly, “in carrying out the public trust doctrine,” the
state and counties may consider “conflicting policy concerns,” including
commerce, recreation, and environmental needs, and “fashion[ ] a
compromise to address the practical realities.” (Carstens v. California
Coastal Com. (1986) 182 Cal.App.3d 277, 289–290.)
Here, we cannot say that Sonoma’s amendments to the ordinance were
arbitrary, capricious, or “entirely lacking in evidentiary support.” (American
Coatings, supra, 54 Cal.4th at p. 460.) To the contrary, the record
demonstrates that Sonoma gathered information, engaged the public, and
subsequently balanced “conflicting policy concerns and fashioned a
compromise to address the practical realities” of groundwater well
permitting. (Carstens v. California Coastal Com., supra, 182 Cal.App.3d at
pp. 289–290.) This is the precise type of legislative discretion that is
presumed valid, and Keepers do not overcome that presumption on this
record.

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We begin with the O’Connor report, which provides evidentiary support
for Sonoma’s decision to adopt the PTRA as “a process for consideration of
impacts to public trust resources.” The O’Connor report considered “many
potential approaches to mapping the PTRA spanning a wide range of
complexity and data requirements” and ultimately developed “risk-based
approach . . . to define the PTRA” because it made “the best use of available
data and numerical models” “given the data and implementation timeline
constraints.” The risk-based approach balanced two public trust concerns—
“Streamflow Depletion” and “Resource Sensitivity”—by designating areas as
either “high,” “moderate” or “low” value (e.g., a “high value habitat” or a low
streamflow depletion).
As for streamflow depletion, the O’Connor report specifically considered
the best ways to measure both “cumulative streamflow depletion,” which
“occurs when the total volume of water pumped by a population of wells
becomes significant relative to the total inflows to the aquifer,” and “acute”
streamflow depletion, which is the short-term depletion caused by individual
well pumping. “There are many methods available for estimating streamflow
depletion due to groundwater pumping,” each with its own “distinct
advantages and disadvantages”; however, under any approach “direct
application . . . at the county-wide scale with limited time and resources is
infeasible.”
Therefore, the O’Connor report proposed “a relatively simple water
balance method to estimate cumulative streamflow depletion that can be
implemented across [Sonoma].” The O’Connor report validated this method
against other models and confirmed it could consistently predict streamflow

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depletion and was therefore “appropriate for [its] intended purpose of
delineating areas with low, medium, or high streamflow depletion.”13
“Resource sensitivity was mapped based on a combination of critical
steelhead and coho habitat” from available information, including 2023 data
from the California Department of Fish and Wildlife and 2012 data from the
National Marine Fisheries Service. The high, medium, and low designations
for resource sensitivity were reviewed by a “group of fisheries experts from
National Marine Fisheries Service, California Department of Fish and
Wildlife, Cal Trout, Sonoma Water, and Sonoma Ecology Center with detailed
local knowledge of habitat conditions,” and as a result, “a new ‘Very High”
sensitivity category was added.”
To map the PTRA, the O’Connor report combined the rankings of
streamflow depletion and resource sensitivity in a “matrix.” The PTRA would
include areas with high or very high habitat value, regardless of streamflow
depletion, as well as areas with moderate habitat value, except where
streamflow depletion was low. Areas with low habitat value were excluded
from the PTRA regardless of streamflow depletion.
Based on the O’Connor report, Sonoma adopted the PTRA as a means
of discharging its obligation to protect public trust resources. (Ch. 25B,
§ 25B-2, subd. (b).) Specifically, Sonoma found that the PTRA encompassed
the areas where “groundwater extraction may impact public trust resources,”
and thus subjected those well applications to a heightened standard of
review. (Ch. 25B, § 25B-4, subd. (d)(2).) In our opinion, the record
demonstrates that Sonoma “considered the facts before it,” “balanc[ed] . . .
13 Further, “water use metering requirements associated with the new
well ordinance would provide valuable data with which to refine estimates of
existing groundwater pumping.”

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public trust rights . . . against the public need for [resources],” and enacted
protections where feasible. (World Business Academy, supra, 24 Cal.App.5th
at pp. 509–510.) Under the deferential standard of review, we cannot say the
resulting amendments were arbitrary, capricious, or entirely lacking in
evidentiary support.
To be sure, during the amendment process, Sonoma considered
expanding the PTRA “to the entirety of the County” but rejected the proposal
based on competing policy considerations. On the one hand, Sonoma found
the “additional areas have low risk” of harming public trust resources while,
on the other hand, expanding the PTRA would increase the costs of
implementation.14 Therefore, Sonoma determined “the additional costs for
permitting and related requirements [were not] commensurate to the
potential impact” on trust resources. Reviewing courts do not “second-guess”
the reasonable exercise of legislative discretion under either the applicable
standard of review or the public trust doctrine. (American Coatings, supra,
54 Cal.4th at p. 476; Monterey Coastkeeper, supra, 76 Cal.App.5th at p. 21
[“The public trust doctrine necessarily involves the exercise of discretion by
state agencies”].)
Nevertheless, because Keepers bear the burden of proof in challenging
the amended ordinance, we discuss their arguments. (American Coatings,
supra, 54 Cal.4th at p. 460.) In this appeal, as they did in the superior court,
Keepers assert Sonoma abused its discretion in amending Chapter 25B,
including by adopting conservation measures and “ministerial” exceptions,
without evidentiary support and without considering the cumulative impacts.
14 The cost of conducting a public trust review was estimated to be
“equivalent to 32 hours of staff time of an Engineer or Professional Geologist
in the amount of $5,568” per application, and the well owner would bear the
costs of preparing the permit application and supporting evidence.

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As we discuss below, we believe these arguments require a level of
scrutiny inconsistent with the applicable standard of review and, in any
event, do not render Sonoma’s decisions arbitrary, capricious, or without
evidentiary support. (American Coatings, supra, 54 Cal.4th at p. 476
[“disagreement” with air protection measures did not provide a “basis for this
court to second-guess the District’s reasonable determinations”]; see also
Citizens for East Shore Parks v. State Lands Com., supra, 202 Cal.App.4th
549, 576 [rejecting argument that the agency had “an obligation to evaluate
the other public trust uses urged by plaintiffs”].)
1. Cumulative Impacts
As an overarching claim, Keepers assert that Sonoma failed to account
for “future and existing cumulative groundwater extractions.” In support of
their argument, Keepers point to internal comments that the “time
constraints” forced working groups “to forgo review of important evidence,
methodologies, and analyses before making recommendations.”
Preliminarily, the record undercuts Keepers’ claim that Sonoma failed
to consider cumulative impacts. The working groups’ report expressly
included “Cumulative impact considerations,” and the O’Connor report
developed the PTRA in order to “estimate cumulative streamflow depletion
[in a way] that can be implemented across the County.”
While “the lack of data [was] a significant impediment to more robust
technical approaches to evaluating impacts to public trust resources,” to
account for “groundwater pumping expansion and cumulative impacts,” the
working groups provided recommendations “to improve the data and
information needed to more accurately evaluate” impacts on public trust
resources. These recommendations were incorporated into the amended
ordinance as metering and monitoring requirements. Thus, Sonoma

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explicitly considered the cumulative impacts in amending Chapter 25B, and
Keepers fail to overcome the presumption of validity. (Corona-Norco, supra,
17 Cal.App.4th at p. 993 [to overcome the presumption, the petition must
produce evidence showing the amendment is “unreasonable and invalid” as a
matter of law].)
Further, under the public trust doctrine, Sonoma is not required to
protect resources in “every conceivable circumstance.” (Monterey
Coastkeeper, supra, 76 Cal.App.5th at p. 21.) In amending Chapter 25B, the
Board took nearly a year, considering and revising the proposed amendments
based on feedback from experts, working groups, interested stakeholders, and
the public. While practical realities imposed some “time constraints [on] the
ordinance development process,” meaning some uncertainty was unavoidable,
Sonoma made reasonable assumptions based on available data and planned
to refine and “update” the review process and PTRA map based on the
additional information received from the metering and monitoring
requirements. Thus, Sonoma exercised reasonable legislative discretion in
considering the evidence before it when amending Chapter 25B, and Keepers’
cumulative impacts claim fails to justify judicial intervention under the
public trust doctrine. (Monterey Coastkeeper, at p. 21 [“This inherently
discretionary doctrine generally does not allow for intervention by the
courts”].)
2. Conservation Measures
Additionally, Keepers claim, “Sonoma adopted the Conservation
Requirements based on speculation that they would mitigate impacts, not on
evidentiary support or analysis.” But this argument flips the burden of proof.
(American Coatings, supra, 54 Cal.4th at pp. 475–476 [“technical
disagreements” “over how strict air pollution limits should be and how long

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industry should have to achieve them” were insufficient to show amendments
were arbitrary, capricious, “or without evidentiary support”].)
As stated earlier, we begin with the presumption that the legislation is
valid and supported by the “ ‘necessary facts.’ ” (Corona-Norco, supra,
17 Cal.App.4th at p. 993.) Therefore, unlike CEQA, where an agency must
offer substantial evidence in support of its findings (California Farm Bureau
Federation v. California Wildlife Conservation Bd. (2006) 143 Cal.App.4th
173, 185), here, Sonoma has no affirmative evidentiary burden to show the
efficacy of the conservation measures. (See Corona-Norco, at p. 993
[petitioner bears the burden of overcoming the presumption of validity];
American Coatings, supra, 54 Cal.4th at p. 460 [“ ‘ “the petitioner always
bears the burden of proof in a mandate proceeding brought under Code of
Civil Procedure section 1085” ’ ”].) Rather, Keepers “must produce evidence
‘compelling the conclusion that the ordinance is, as a matter of law,
unreasonable and invalid.’ ” (Corona-Norco, at p. 993.)
Keepers have not met that burden here. During the amendment
process, the policy working group was tasked with considering conservation
measures and agreed on the Level 1 and Level 2 conservation requirements.
However, working group members were “evenly split” on types of wells to
which each level would apply. Some members recommended the Levels 1 and
2 conservation requirements apply to new wells using less than two AFY of
water while replacement wells would be exempt or subject to only Level 1
requirements; other members suggested Level 1 requirements apply to wells
using less than half an AFY, while Levels 1 and 2 apply to wells using
between half and two AFY.
Sonoma’s decision to use the two AFY threshold was a reasonable
exercise of its legislative discretion because it “considered [the] alternative”

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and “nevertheless” adopted “the 2.0-acre-feet-per-year threshold for
consistency with state law”15 and because the more restrictive alternative
“could have undue economic impact and substantially restrict many ‘by right’
land uses and the reasonable use of one’s property, including use of water for
human health and habitation.” (See Ch. 25B, §§ 25B-12, 25B-13.)
At best, Keepers offer evidence that additional or different conservation
measures may have provided greater protection to public trust resources, but
“evidence, even substantial evidence, supporting a different categorization” is
insufficient to defeat the amended ordinance as a whole. (American Coatings,
supra, 54 Cal.4th at pp. 475–476.) Even under the public trust doctrine,
Sonoma may “approve appropriations despite foreseeable harm to public
trust uses.” (National Audubon, supra, 33 Cal.3d at p. 446.)
3. Ministerial Exceptions
Keepers likewise claim, “Sonoma’s establishment of ministerial well
categories failed to consider all relevant factors and lacked evidentiary
support.” Keepers challenge Sonoma’s finding of an “overriding public
interest” justifying exemption from public trust review and cite comments
from Sonoma’s staff stating that the net zero increase well category needed “a
lot of work . . . before it can be applied broadly.”16 Keepers’ challenges again
flip the burden of proof.
15 As Sonoma explained during the amendment process, “California
Water Code [section] 10721 defines ‘de minimis extractor’ as a person who
extracts . . . less than 2.0 acre-feet per year for domestic purposes. The recent
governor’s executive order N-7-22 exempts permits for wells that will provide
less than 2.0 acre-feet per year of groundwater for individual domestic users
from additional requirements and review.”
16 Keepers also challenge the two AFY threshold with respect to the low
use well category. As we have already discussed, adopting the two AFY
threshold was a reasonable exercise of discretion. Moreover, the alternative
proposal of a 0.5 AFY threshold was based on “the average groundwater use

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Sonoma found that the ministerial categories were justified by two
findings: “the low potential for impacts to public trust resources” and “the
overriding public interest in favor of ensuring adequate water support for
existing and domestic uses.” (Ch. 25B, § 25B-4, subd. (e).) The low impact
finding was supported by the O’Connor report, as discussed above, and the
public interest is a policy consideration, the “wisdom” and “ ‘merits’ ” of which
we “ ‘cannot’ ” review on appeal. (San Francisco Tomorrow, supra,
229 Cal.App.4th at p. 509.)
As for Keepers’ challenge to the net zero use category, while Sonoma
staff stated the category would require “a lot of work,” the statement was
made with respect to creating “objective standards” that could be “applied
broadly,” because until then, net zero use well permits would require
preparation and review of a “recharge plan and report” prepared by a
hydrogeologist, which could be costly.17 (Ch. 25B, § 25B-4, subd. (e)(8)(ii).)
Thus, the staff comment was not a criticism of the category as amended, but
rather, a statement about future work to standardize the process and does
not undermine Sonoma’s legislative discretion.
of a rural single-family residence” per year. Thus, as a mathematical matter,
adoption of the lower threshold would mean that that families using more
than 0.5 AFY would be excluded from the low use category not based on
unreasonable water use or threat to public trust resources, but because they
happened to be above the average. Such a decision might very well
“substantially restrict many ‘by right’ land uses and the reasonable use of
one’s property . . .” as Sonoma found.
17 Although the well applicant would bear the costs of preparing the
report, the discretionary review process was anticipated to cost Sonoma
money and manpower, which provides a further rational basis for creating
ministerial well categories.

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In sum, applying the appropriate standard of review, we conclude
Keepers do not satisfy their burden of demonstrating that Sonoma failed to
consider the public trust doctrine in amending Chapter 25B.
II. CEQA
CEQA “establishes a comprehensive scheme to provide long-term
protection to the environment.” (Berkeley Hillside Preservation v. City of
Berkeley (2015) 60 Cal.4th 1086, 1092; see also Sunflower Alliance v.
Department of Conservation (2026) 20 Cal.5th 22, 39–40.) Thus, CEQA and
the Guidelines “establish a three-tier process to ensure that public agencies
inform their decisions with environmental considerations.” (Muzzy Ranch
Co. v. Solano County Airport Land Use Com. (2007) 41 Cal.4th 372, 380
(Muzzy Ranch).)
First, the agency determines whether the activity constitutes a
“project” subject to CEQA’s regulations. (Muzzy Ranch, supra, 41 Cal.4th at
p. 380.) Second, the agency considers whether the project is “exempt” from
CEQA review. (Muzzy Ranch, at p. 380.) If a project is exempt, then “no
further environmental review is necessary”; however, if no exemption applies,
then “the agency must ‘conduct an initial study to determine if the project
may have a significant effect on the environment.’ ” (Id. pp. 380–381.) Third,
“if the agency determines substantial evidence exists that an aspect of the
project may cause a significant effect on the environment,” the agency must
prepare an environmental impact report (EIR). (Ibid.) Here, we are
concerned with the exemptions under the second step.18
18 There are also “exceptions” to the “exemptions”; even if a project is
categorically exempt from CEQA review, it “may nonetheless require review
under CEQA if it falls within one of the exceptions to the exemptions.”
(Robinson v. City and County of San Francisco (2012) 208 Cal.App.4th 950,
956, italics added.) Here, Keepers asserted that the “cumulative impacts”

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“In general, judicial review of agency actions for CEQA compliance
extends to ‘whether there was a prejudicial abuse of discretion.’ ” (Protecting
Our Water & Environmental Resources v. County of Stanislaus (2020)
10 Cal.5th 479, 495.) “Abuse of discretion is established if the agency has not
proceeded in a manner required by law or if the determination or decision is
not supported by substantial evidence.” (Pub. Resources Code, § 21168.5;
Nassiri v. City of Lafayette (2024) 103 Cal.App.5th 910, 920.)
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.” (Guidelines, § 15384, subd. (a).) Substantial evidence includes
“expert opinion supported by facts” but not [a]rgument, speculation, [or]
unsubstantiated opinion or narrative.” (Id., § 15384, subds. (a), (b).)
“When an agency concludes an activity is exempt [from CEQA] based
on factual considerations, a court reviews for substantial evidence. If the
agency’s determination ‘involves pure questions of law, we review those
questions de novo.’ ” (Protecting Our Water & Environmental Resources v.
County of Stanislaus, supra, 10 Cal.5th at p. 495; see also John R. Lawson
Rock & Oil, Inc. v. State Air Resources Bd. (2018) 20 Cal.App.5th 77, 103–104
[considering determination of baseline de novo].)
In amending Chapter 25B, Sonoma claimed the amendments were
exempt from CEQA review under the Class 7 and Class 8 categorical
exemptions, which exclude from CEQA review actions taken “to assure the
maintenance, restoration, or enhancement of a natural resource” or “the
exception precluded Sonoma’s reliance on categorical exemptions. Because
we conclude Sonoma failed to support its claimed exemptions, we do not
reach Keepers’ asserted exceptions.

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environment.” (Guidelines, §§ 15307, 15308.) Additionally, Sonoma asserted
the “common sense exemption” applied, which excuses CEQA review “[w]here
it can be seen with certainty that there is no possibility that the activity in
question may have a significant effect on the environment.” (Guidelines,
§ 15061, subd. (b)(3).)
The superior court disagreed with Sonoma, concluding the “record
demonstrates no substantial evidence” that the amended ordinance fell
within either the categorical exemptions or the common sense exemption.
The court reasoned that the baseline was the “moratorium on all new wells
except for emergency permits, adopted in October 2022,” and thus the
amendments were “a ‘relaxation’ of” the environmental protection offered by
the moratorium.
On appeal, Sonoma argues the superior court incorrectly determined
the baseline, which should have been the ministerial well permitting in effect
prior to the moratorium, and that substantial evidence supports the claimed
exemptions. Although we agree the moratorium is the incorrect baseline,
Sonoma still fails to show the claimed exemptions apply and are supported by
substantial evidence.19
19 Sonoma makes two additional arguments that we dispose of by way
of footnote. First, Sonoma suggests that “Keepers waived the issue of
whether there is substantial evidence supporting [Sonoma’s] exemption
conclusion” by failing to argue that substantial evidence was lacking in their
respondent’s brief. We decline to find waiver since Sonoma’s only supporting
authority states that an “appellant’s failure to raise an issue in his or her
opening brief” waives that challenge. (Paulus v. Bob Lynch Ford, Inc. (2006)
139 Cal.App.4th 659, 685, italics added.) Although inadvisable, “even a
respondent’s complete failure to address an appellant’s argument does not
require us to treat the failure to respond as a concession the argument has
merit.” (Griffin v. The Haunted Hotel, Inc. (2015) 242 Cal.App.4th 490, 505.)
Second, Sonoma argues that the Level 1 and Level 2 conservation
requirements are not “mitigation measures,” as Keepers asserted below and

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A. Class 7 and Class 8 Categorical Exemptions
Under CEQA, “the agency invoking the exemption has the burden of
demonstrating it applies.” (Muzzy Ranch, supra, 41 Cal.4th at p. 386.) On
review, we consider de novo whether the amended ordinance meets the
definition of the asserted categorical exemption and, if so, we review the
factual findings for substantial evidence. (Fairbank v. City of Mill Valley
(1999) 75 Cal.App.4th 1243, 1251.) We “construe the exemptions narrowly in
order to afford the fullest possible environmental protection.” (Save Our
Carmel River v. Monterey Peninsula Water Management Dist. (2006)
141 Cal.App.4th 677, 697 (Save Our Carmel River).)
As noted above, the Class 7 and Class 8 categorical exemptions exclude
from CEQA review actions taken “to assure the maintenance, restoration, or
enhancement of a natural resource” or “the environment.”20 (Guidelines,
§§ 15307, 15308.) “Case law is instructive as to which actions fall within
these exemptions, and which do not. The prohibition of an activity that
evidence shows is associated with ‘environmental problems, [such as] the
on appeal. (See also Azusa Land Reclamation Co. v. Main San Grabiel Basin
Watermaster (1997) 52 Cal.App.4th 1165, 1199–1200 [“mitigation measures
cannot be used to support a categorical exemption”].) We do not reach the
argument, because even assuming the conservation requirements are
permissible, Sonoma still fails to carry its burden of showing the exemptions
apply and are supported by substantial evidence. (Muzzy Ranch, supra,
41 Cal.4th at p. 386.)
20 Notably, the concept of a baseline is not applicable to the Class 7 and
Class 8 categorical exemptions. (Save Our Big Trees v. City of Santa Cruz
(2015) 241 Cal.App.4th 694, 711 (Save Our Big Trees) [“whether the Project
will have a significant effect on the environment is not the standard for
determining whether it falls within a categorical exemption”; “the standard is
whether substantial evidence supports the determination that the Project
will assure the maintenance, restoration, or enhancement of the
environment” or a natural resource].)

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contamination of farmland,’ constitutes an action to assure ‘protection of the
environment.’ ” (Save Our Big Trees, supra, 241 Cal.App.4th at p. 707.) “By
contrast, actions that remove existing wildlife protections, authorize and
regulate hunting, or relax existing environmental safeguards do not assure
the maintenance, restoration, or enhancement of the environment.” (Id. at
p. 707.) “These legal guideposts indicate that” the Class 7 and Class 8
exemptions “embrace[ ] projects that combat environmental harm, but not
those that diminish existing environmental protections.” (Ibid.)
Here, as a matter of law, we fail to see how the amendments qualify as
actions “to assure the maintenance, restoration, or enhancement” of the
environment. (Guidelines, §§ 15307, 15308, italics added.) Rather, like in
Wildlife Alive v. Chickering (1976) 18 Cal.3d 190, 205, where the setting of
hunting and fishing seasons was not categorially exempt as preserving
natural resources; here, Chapter 25B regulates private activity that may
have “an indirect beneficial effect on [natural resources],” but “cannot fairly
or readily be characterized as a preservation activity in a strict sense.”
Even assuming the amendments would have some beneficial impacts,
Keepers note that the amendments also relax some regulations.21 Thus, at
best, the amended ordinance both strengthens and weakens environmental
protections, which does not fall within the scope of the Class 7 or Class 8
categorical exemptions. (See also Save Our Big Trees, supra, 241 Cal.App.4th
at pp. 707–713 [regulation of removal of trees not categorically exempt
because, “Even assuming the [amendment] will not actually result in
21 Prior to the amendment, Chapter 25B required destruction of an
existing well upon completion of construction of a replacement well.
However, the amended version of Chapter 25B provides 180 days for
destruction, allowing for six months of joint use.

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additional tree removals . . . , that does not render it an action to assure the
maintenance, restoration, or enhancement of the environment”].)
Sonoma makes the feeble argument that the Class 7 and 8 exemptions
“apply to ‘action taken . . . to assure’ environmental protection,” which means
the agency does not need “to prove the regulatory action will be 100 percent
effective at all times,” only that “the agency’s objective intent and purpose”
was to protect the environment. Sonoma’s argument is inconsistent with
CEQA’s definition of substantial evidence, which excludes “unsubstantiated
opinion” (Guidelines, § 15384, subd. (a)); case law, which deems an agency’s
intent “irrelevant” (Save Our Big Trees, supra, 241 Cal.App.4th at p. 710
[city’s “intent . . . not to ‘encourage’ tree removal” was “irrelevant”]); and the
general policy of narrowly construing exemptions. (Save Our Carmel River,
supra, 141 Cal.App.4th at p. 697.)
In any event, Sonoma also fails to support the asserted Class 7 or
Class 8 exemptions with substantial evidence. Sonoma reasons that “because
the Amendment creates protections where non previously existed,” it is ipso
facto exempt. We are unpersuaded. Sonoma received an average of
anywhere from 280 to 320 well permits per year between 2017 and 2022.
However, Sonoma estimated the amended ordinance’s discretionary review
process would apply to between five and 30 applications. Thus, according to
Sonoma’s own calculations, approximately 95 percent of applications would
remain subject to ministerial review, meaning the amendments cannot be
automatically assumed “to assure the maintenance, restoration, or
enhancement” of the environment or a natural resource. (Guidelines,
§§ 15307, 15308.)
As for the five percent subject to discretionary review, there is no
evidence in the record that any permits would be denied in the review

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process, and even if an application were denied, the applicant could appeal to
the Board, which may, if requested by the enforcing agency, approve the
application based on “overriding considerations that balance the protection of
public trust resources with the health, safety and welfare needs of the
community, including the need for drinking water.” (Ch. 25B, § 25B-4,
subd. (d)(6),(7).) Thus, it is speculative to assume that the amendments to
Chapter 25B would result in any permit denials or fewer wells. (Guidelines,
§ 15384, subd. (a) [“Argument, speculation, [or] unsubstantiated opinion . . .
does not constitute substantial evidence”].)
Further, there is no substantial evidence that the Level 1 and 2
conservation measures will maintain, restore, or enhance the environment or
a natural resource. Although Sonoma “anticipated” and “expected” the
conservation measures would “decrease” net groundwater use “over time,”
Sonoma acknowledged it could not “quantify” any benefits from the
conservation measures because its estimates were subject to “quite a bit of
err or uncertainty.” Water conservation measures were also beyond the scope
of the O’Connor report, which only noted in the introduction, “Additional
review and water conservation requirements are intended to avoid or
mitigate adverse impacts to [public trust resources].”
Thus, unlike our deferential review of the public trust claim where
Sonoma was entitled to a presumption that it ascertained the necessary facts
(Corona-Norco, supra, 17 Cal.App.4th at p. 993), under CEQA, Sonoma’s
“intent” to enhance the environment is not sufficient to satisfy its burden of
proof. (Save Our Big Trees, supra, 241 Cal.App.4th at p. 710.) Sonoma’s
expectation or “ ‘understanding’ ” that the conservation requirements will
reduce water use “does not amount to substantial evidence within the
meaning of CEQA.” (Save Our Carmel River, supra, 141 Cal.App.4th at

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p. 698 [finding categorical exemption for replacement or reconstruction of
existing facilities did not apply to approval of “water credit” transfer that
allowed for additional water allocation at new construction site based on
demolition of commercial building (and thus reduction in water use) at a
different location].)
In short, Sonoma “bears the burden to demonstrate with substantial
evidence” that the amended ordinance will restore or enhance the
environment, and the CEQA challenger “bears no burden to show the Project
will degrade the environment or deplete a natural resource.” (Save Our Big
Trees, supra, 241 Cal.App.4th at pp. 710–711.) Assuming the Class 7 and
Class 8 exemptions are applicable, the record does not contain substantial
evidence that the amendments to Chapter 25B are actions “to assure the
maintenance, restoration, or enhancement of a natural resource” or “the
environment.” (Guidelines, §§ 15307, 15308.)
B. Common Sense Exemption
A project that does not qualify for a categorical exemption “may
nonetheless be found exempt under what is sometimes called the
‘commonsense’ exemption, which applies ‘[w]here . . . there is no possibility
that the activity in question may have a significant effect on the
environment.’ ” (Muzzy Ranch, supra, 41 Cal.4th at p. 380, quoting
Guidelines, § 15061, subd. (b)(3).) “There is no ‘ironclad definition of [what
constitutes a] significant effect.’ ” (Keep Our Mountains Quiet v. County of
Santa Clara (2015) 236 Cal.App.4th 714, 729.)
Under the common sense exemption, if “there is a reasonable
possibility that a proposed project will have a significant effect upon the
environment, then the lead agency must conduct an initial study.”
(California Farm Bureau Federation v. California Wildlife Conservation Bd.,

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supra, 143 Cal.App.4th at p. 194, italics omitted.) “A remote or outlandish
possibility of an environmental impact will not remove a project from the
commonsense exemption, but if legitimate, reasonable questions can be
raised about whether the project might have a significant impact, the agency
cannot find with certainty the project is exempt.” (Id. at p. 194.) Thus, the
common sense exemption “is ‘reserved for those “obviously exempt” projects,
“where its absolute and precise language clearly applies.” ’ ” (Ibid.)
In considering whether the common sense exemption applies, courts
have considered the relevant baseline. (See, e.g., CREED-21 v. City of San
Diego (2015) 234 Cal.App.4th 488, 504–507, 510–513 [finding trial court
applied improper baseline in considering common sense exemption].) Thus,
we begin by addressing the correct baseline, which is “the actually existing
physical conditions” when the environmental analysis is commenced, and not
the “hypothetical conditions that could have existed under applicable permits
or regulations.” (Neighbors for Smart Rail v. Exposition Metro Line
Construction Authority (2013) 57 Cal.4th 439, 448 (Neighbors).) The term
“baseline” comes from the Guidelines on contents of an EIR, which must
include “a description of the physical environmental conditions” in order to
evaluate whether the project will have a significant impact on the
environment.22 (See Guidelines, § 15125, subd. (a); see also North Coast
Rivers Alliance v. Westlands Water Dist. (2014) 227 Cal.App.4th 832, 872.)
While the agency “enjoy[s] discretion . . . related to the choice of a
measurement technique for existing conditions,” it is required to measure the
“existing conditions baseline.” (Neighbors, supra, 57 Cal.4th at p. 449.)
22 “ ‘Significant effect on the environment’ means a substantial, or
potentially substantial, adverse change in any of the physical conditions
within the area affected by the project.” (Guidelines, § 15382; see also Pub.
Resources Code, § 21083, subd. (b).)

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Therefore, applicable regulations may be informative in measuring existing
conditions, but they cannot supplant “recent history of actual[ ]” use. (North
County Advocates v. City of Carlsbad (2015) 241 Cal.App.4th 94, 105.)
Here, not only did Sonoma’s amendment process begin before the
moratorium was adopted, but the moratorium represents the then-current
regulatory scheme, not “the actually existing physical conditions,” making the
number of well permits issued during the moratorium an improper baseline.
(See Neighbors, supra, 57 Cal.4th at pp. 448, 450 [approving “a realistic
measure of existing conditions” as “water allocation approximating the
property’s recent historical use”], citing Cherry Valley Pass Acres &
Neighbors v. City of Beaumont (2010) 190 Cal.App.4th 316, 336–340
[approving baseline based on 2004 groundwater use while property operated
as an egg farm, notwithstanding cessation of operations in 2005, where
environmental study began in December 2004].) As Keepers suggest, the
baseline is more appropriately measured by the number of existing wells
prior to the moratorium, “their annual water usage, and the resulting
groundwater and streamflow conditions.”23
23 Keepers suggest that that “prior illegal conduct” cannot serve as the
existing conditions, and thus “Sonoma’s past failure to comply with the Public
Trust Doctrine” cannot serve as the baseline. Keepers’ cited case law,
however, undermines their argument. In Riverwatch v. County of San Diego
(1999) 76 Cal.App.4th 1428, 1453, the Court of Appeal determined CEQA was
not the appropriate vehicle for adjudicating prior illegal activity: “Because
the prior illegality was subject to enforcement actions . . . , CEQA did not
require any further accounting for prior activity at or within the vicinity of
the project.” And Lighthouse Field Beach Rescue v. City of Santa Cruz (2005)
131 Cal.App.4th 1170, 1188, 1197, expressly considered the prior illegal
activity (i.e., the de facto policy of “non-enforcement” of leash laws) in finding
the city failed to adequately analyze the potential for “increases in such off-
leash dog use” caused by “the policy change” of removing the leash
requirements altogether. Therefore, we do not pass on the validity of the pre-

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However, regardless of the baseline, Sonoma offers no substantial
evidence in support of the common sense exemption. As discussed above, any
assumption that the amended ordinance will result in fewer wells or a
decrease in water use is not supported by substantial evidence. Thus, it
cannot be said “with certainty” that the amendments have “no possibility” for
causing a significant effect on the environment. (Guidelines, § 15061,
subd. (b)(3).)
Therefore, Sonoma fails to offer substantial evidence that either
common sense exemption or the Class 7 or 8 categorial exemptions excuse the
amended ordinance from CEQA review.24
In conclusion, we reverse the judgment in part and affirm in part.25
Insofar as the judgment issued a peremptory writ of mandate and ordered
Sonoma to set aside and void the amended ordinance under the public trust
doctrine, the judgment is reversed; the amendments are not void. Insofar as
amendment Chapter 25B in concluding the moratorium is the incorrect
baseline.
24 Although we conclude Sonoma has failed to comply with CEQA, we
note that such noncompliance does not “undermine[ ] the otherwise facially
adequate public trust doctrine analysis.” (World Business Academy, supra,
24 Cal.App.5th at p. 510.) We also express no opinion as to the manner in
which CEQA should be complied with or whether any moratorium or
intervening measures concerning non-emergency well permits are
appropriate.
25 Because we reverse in part, we do not address Sonoma’s arguments
regarding its objections to the judgment, which, as Keepers correctly argue,
were untimely. (Cal. Rules of Court, rule 3.1590(j); In re Marriage of Steiner
& Hosseini (2004) 117 Cal.App.4th 519, 524 [applying 10-day limit under a
prior version of Cal. Rules of Court, rule 3.1590 to a proposed judgment]; see
also In re Marriage of Fossum (2011) 192 Cal.App.4th 336, 346 [“Because he
did not raise the issue [about the judgment] in the trial court, [appellant]
forfeited his right to complain on appeal about the trial court’s lack of
specificity”].)

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the judgment rescinded the notice of categorical exemption issued in
connection with the adoption of the amendment of Chapter 25B, the
judgment is affirmed.
On remand, the court is directed to vacate its October 30, 2024
judgment and November 15, 2024 writ of mandate and enter a new judgment
denying Keepers’ petition for writ of mandate insofar as it challenges the
amended ordinance under the public trust doctrine.26
DISPOSITION
The judgment is affirmed in part and reversed in part, and the matter
is remanded to the superior court to enter a new judgment consistent with
this opinion. Each party to bear their own costs of appeal.
26 Given our partial reversal, the court may reconsider whether
Keepers are the prevailing party entitled to costs and/or attorney’s fees.

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DESAUTELS, J.
We concur:
RICHMAN, ACTING P.J.
MILLER, J.

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Russian Riverkeeper et al. v. County of Sonoma (A172760)

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Trial Court: Sonoma County Superior Court
Trial Judge: Hon. Bradford DeMeo
Attorneys for Defendant and Best Best & Krieger LLP
Appellant County of Sonoma: Scott W. Ditfurth
Amy E. Hoyt
Patricia Ursea
Zachary N. Scalzo
Amicus Curiae on behalf of BKS Law Firm PC
Defendant and Appellant Kristin B. Peer
County of Sonoma: Jennifer T. Buckman
Ryan S. Bezerra
Robert G. Putka
for Association of California Water
Agencies
Downy Brand LLP
Austin C. Cho
for California State Association of
Counties
Attorneys for Plaintiffs and Carsten, Black & Minteer, LLP
Respondents Russian Riverkeeper Michelle N. Black
and California Coastkeeper Amy C. Minteer
Alliance:
Sycamore Law, Inc.
Daniel Cooper
Drevet Hunt
Jaime Neary
Amicus Curiae on behalf of Shute Mihaly & Weinberger, LLP
Plaintiffs and Respondents William J. White
Russian Riverkeepers and Winter King
California Coastkeeper Alliance: Aidan Freeman
for Endangered Habitats League
Environmental Law Clinic, Mills
Legal at Stanford Law School

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Deborah A. Sivas
Amanda D. Zerbe
Matthew J. Sanders
for California Law Professors
Nathaniel H. Kane
James R. Wheaton
Lowell K. Chow
for Environmental Law Foundation

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