Filed 4/30/14
                             CERTIFIED FOR PUBLICATION




           IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA
                              THIRD APPELLATE DISTRICT
                                             (Shasta)



PHILIP L. BIRON, as Trustee, etc., et al.,                         C071094

                Plaintiffs and Appellants,                 (Super. Ct. No. 167508)

      v.

CITY OF REDDING,

                Defendant and Respondent.



     APPEAL from a judgment of the Superior Court of Shasta County, Monica
Marlow, Judge. Affirmed.

      McNeill Law Offices and Walter P. McNeill for Plaintiffs and Appellants.

      Damien M. Schiff and Anthony L. François for Pacific Legal Foundation as Amici
Curiae on behalf of Plaintiffs and Appellants.

      Richard A. Duvernay and Lynette M. Frediani, City Attorneys for Defendant and
Respondent.



      Plaintiffs Biron Family Living Trust and Philip L. and Julie M. Biron as trustees
own a 12-unit apartment building in downtown Redding, California, which they
purchased in 2001. In February and March 2009, their property was damaged by
flooding during two separate storm events. They filed this action against defendant City

                                                1
of Redding (City), alleging inverse condemnation and dangerous condition of public
property.
       The matter was bifurcated, and tried to the court without a jury as to liability.
Following the plaintiffs’ presentation of evidence, City moved for judgment pursuant to
Code of Civil Procedure section 631.8, subdivision (b), and the trial court granted the
motion only as to the allegations of flooding occurring in March 2009. The trial
proceeded as to the allegations of flooding occurring in February 2009.
       The trial court ruled in favor of City on both causes of action. As to the inverse
condemnation claim, it applied the rule of reasonableness to conclude that City’s decision
to defer upgrades to City’s storm drainage system did not pose an unreasonable risk of
harm to plaintiffs. As to the cause of action for dangerous condition of public property,
the court concluded City’s decision to defer upgrades to the storm drainage system did
not create a substantial risk of injury to members of the general public, and that even if
the storm drain system had been a dangerous condition, City’s conduct was reasonable.
       Plaintiffs argue the trial court erred in applying a rule of reasonableness to the
inverse condemnation cause of action, and claim City should have been strictly liable for
the damage. Plaintiffs make no focused argument with respect to the dangerous
condition of public property claim, other than to reiterate that City knew the storm
drainage facilities were deficient, and that the facilities were a dangerous condition of
public property.
       We shall affirm the judgment.
       The trial court was correct in determining that City’s inverse condemnation
liability was determined by a rule of reasonableness. Moreover, the trial court’s findings
of fact lead to the conclusion that the storm drain facilities were not a substantial cause of
plaintiffs’ damage. The trial court’s finding that City acted reasonably, reasonableness
being a complete defense to the dangerous condition of public property claim, is
supported by substantial evidence.

                                              2
                   FACTUAL AND PROCEDURAL BACKGROUND
       The trial court filed a lengthy and detailed statement of decision. Plaintiffs make
no claim that the evidence was insufficient to support the trial court’s findings of fact.
Therefore we derive most of the factual background in this opinion from the trial court’s
findings of fact contained within the statement of decision.
       The Biron property is a 12-unit apartment building located at 2487 Court Street in
downtown Redding. It is not directly adjacent to a natural watercourse, but there is a
natural watercourse approximately a block away. The owner of the property adjacent to
plaintiffs’ installed a brick wall and floodgates because storm water had flooded that
property in the past. The adjacent floodgates were in place when plaintiffs purchased
their property in 2001.
       City designed, constructed, and maintained a storm drainage system on and around
plaintiffs’ property as a means of surface water and flood control.1 The facilities are
intended in part to protect property, including plaintiffs’ property. The Biron property is
not within a mapped flood plain. There is a 36-inch storm drain inlet in the center of the
parking lot on the Biron property. It falls outside City’s easement for the purpose of
storm drain maintenance, thus is privately owned and controlled by plaintiffs, who have
the responsibility for its maintenance.
       In 1993 Montgomery Watson Engineers contracted with City to prepare a city-
wide master storm drain study (Study), which evaluated the city’s storm drain facilities
and made recommendations for repair and replacement. The purpose of the Study was to
recommend upgrades and an implementation plan which would allow safe conveyance



1 Plaintiffs object to City’s characterization of the storm drain system as a flood control
project because City’s attorney admitted the system was “not a flood control project, per
se.” Of course, the statement of an attorney is not evidence. Plaintiffs do not point to
any evidence that the purpose of the storm drain system was not to collect surface water
and prevent flooding, whether or not it was “per se” a flood control project.

                                              3
for floodflows from specific storm magnitudes (i.e., 10-year storms, 25-year storms, 100-
year storms).
       The Study contained a capital improvement plan, which set forth facilities needing
improvement to convey future development design flows. The deficient facilities were
ranked in order of priority, with the highest priority given to those facilities that were the
most deficient, and the lowest priority given to those facilities that were the least severely
undersized. Most of the downtown Redding facilities, where plaintiffs’ property is
located, were assigned the lowest priority because “the majority of the problems in that
area consist[ed] of nuisance flooding [less than 2 feet deep, with low velocities] in the
streets.” Five facilities in the immediate vicinity of plaintiffs’ property were included in
the capital improvement plan. The recommended level of protection for all but one of the
five facilities was a 25-year storm design. A 100-year storm design was recommended
for the remaining facility. All five were assigned a priority of six, which was the lowest
priority assigned in the capital improvement plan. None of the downtown facilities
identified by the Study as deficient were ever improved. There was no evidence that the
volume of runoff into the storm drain system increased as a result of development since
the 1993 Study.2
       City considered the storm drain utility to be grossly underfunded and lacking in
available funds for improvement. The Study estimated the cost of recommended
improvements to the facilities in the downtown area (where the Biron property is located)
to be approximately $7.5 million. The cost of the recommended improvements for all




2 Plaintiffs’ reply brief argues there was evidence of properties that were built without
drainage mitigation. However, defendant’s witness testified the amount of rainfall that
was diverted from the watershed exceeded the amount of impervious surface that may
have been created by unmitigated development.

                                              4
other facilities identified in the Study throughout the city was approximately $14.5
million.
       In 1992 or 1993 there was a flood on the Biron property and on the adjacent
Cresswell property. Afterward, a brick wall and floodgates were installed on the adjacent
Cresswell property. In the flood of 1992 or 1993, two to three inches of flooding
occurred inside the apartment complex that was later purchased by the Birons. The
Birons were not aware of the 1992 or 1993 flood.
       Storms resulting in flooding occurred on February 23 and March 16, 2009. A
tenant of the Birons’ apartment complex testified that the amount of water entering the
Biron property and the direction of the water flow were the same in both instances. The
parties’ experts agreed that the March 16, 2009, event was a greater than 100-year event.
It was thus considered to be the result of an “ ‘act of God’ ” for which City bore no
responsibility.
       Two nearby rain gauges recorded precipitation from the storms. One recorded a
16-year storm event on February 23, 2009. One recorded a 100-year storm event on
February 23, 2009. The trial court found that the February 23, 2009, storm event was
more consistent with a 100-year frequency storm.
       The flooding on the Biron property was not caused by City’s poor maintenance of
the system. The trial court found the flooding was caused by a storm event that was akin
to a 100-year event, which overwhelmed both natural watercourses and storm drain
infrastructure, causing water to backup onto the street adjacent to the Biron property, to
surcharge3 through the storm drain inlet on the Biron property, and to run overland,
finding the lowest path downstream via another adjacent street. The water from the
adjacent streets entered the Biron property. The trial court also found that a cyclone and



3A drain surcharges when water gushes upward and out rather than taking drainage
water in.

                                             5
a wood fence, as well as railroad ties placed on the Biron property impeded downstream
draining.
       The trial court ruled in favor of City on both the inverse condemnation and
dangerous condition of public property causes of action. In analyzing the inverse
condemnation cause of action, the court applied the “rule of reasonableness” set forth in
Locklin v. City of Lafayette (1994) 7 Cal.4th 327, 362 (Locklin). Pursuant to Locklin, the
trial court analyzed the overall public purpose being served by the improvement, the
degree to which the plaintiffs’ loss was offset by reciprocal benefits, the availability to
the public entity of feasible alternatives with lower risks, the severity of plaintiffs’
damage in relation to risk-bearing capabilities, the extent to which damage of the kind
plaintiffs sustained is generally considered as a normal risk of land ownership, and the
degree to which similar damage is distributed at large over other beneficiaries of the
project or is peculiar only to plaintiffs.
       The trial court also considered five factors set forth in Albers v. County of Los
Angeles (1965) 62 Cal.2d 250 (Albers): (1) whether the damage if reasonably
foreseeable, would have entitled the property owners to compensation; (2) the likelihood
of public works not being engaged in because of unforeseeable direct damage to
property; (3) whether the damage was the proximate result of the work as deliberately
planned and carried out; (4) whether the damage can better be absorbed, and with less
hardship, by the taxpayers as a whole; and (5) whether the owner, if uncompensated,
would contribute more than a proper share to the public undertaking.
       Considering all of the above factors, the trial court concluded City did not act
unreasonably in deciding to defer upgrades to the storm drainage system in the downtown
area, and that City’s decision to defer upgrades did not pose an unreasonable risk of harm
to plaintiffs. The trial court also found plaintiffs did not prove that the storm drain
system created a situation or risk that would not otherwise have been present, nor did
they prove that the storm drain system exposed plaintiffs’ property to a risk of flooding

                                               6
that did not otherwise exist. The trial court characterized plaintiffs’ claim as an argument
that City did not do enough to protect their property.
       As to plaintiffs’ dangerous condition of public property cause of action, the trial
court concluded the storm drain was designed to a 10-year storm capacity, and that it
performed as expected. The court concluded that the risk identified by the 1993 Study
was of nuisance flooding, which did not create a substantial risk of injury to members of
the general public. It also weighed the likelihood and seriousness of the potential injury
against the practicality and cost of protecting against the risk of injury and concluded that
any failure to take steps to protect against the risk of injury was reasonable.
                                         DISCUSSION
                                               I
                                     Inverse Condemnation
A. Rule of Reasonableness versus Strict Liability
       Plaintiffs argue the applicable standard of liability for inverse condemnation under
these facts is strict liability, and that the trial court erred in applying a rule of
reasonableness. Plaintiffs argue there are only two exceptions to strict liability in an
inverse condemnation action, and that neither exception is applicable here. Plaintiffs
claim the only two exceptions to the rule of strict liability are: (1) where the public entity
as an upper riparian owner would otherwise be privileged to drain surface water into a
natural watercourse, and (2) where the public agency undertakes a flood control project to
relieve from flooding lands historically subject to flooding. Plaintiffs argue the
exceptions do not apply here because City’s storm drain system did not discharge surface
waters into a natural watercourse, and it was not a flood control project for the protection
of lands that were historically subject to flooding.
       The question of whether to apply a standard of reasonableness is a legal issue we
review de novo. (Gutierrez v. County of San Bernardino (2011) 198 Cal.App.4th 831,
844.) We shall conclude that the storm drain system was a method of flood control that


                                                 7
was designed to divert potentially dangerous natural water flow and protect property,
including plaintiffs’ property, against potential flooding. Although plaintiffs’ attempt to
strictly narrow the application of the rule of reasonableness, its application is not as
narrow as they claim, and application of the rule in this situation is consistent with public
policy.
          Inverse condemnation cases originally were analyzed with reference to traditional
tort and property law concepts under the assumption that inverse condemnation liability
tracked private party liability. (Bunch v. Coachella Valley Water Dist. (1997) 15 Cal.4th
432, 439 (Bunch).) The Supreme Court changed this assumption in Albers, supra, 62
Cal.2d 250, which held that a property owner may recover just compensation from a
public entity for “any actual physical injury to real property proximately caused by [a
public] improvement as deliberately designed and constructed . . . whether foreseeable or
not.” (Id. at pp. 263-264.)
          Albers, supra, 62 Cal.2d 250, recognized two exceptions to the rule of strict
liability: (1) where the damages were inflicted in the proper exercise of the public
entity’s police power, and (2) where the public entity had a common law right to inflict
damage, as where an upper riparian owner is privileged to protect against the common
enemy of floodwaters. (Bunch, supra, 15 Cal.4th at pp. 440-441.) This second exception
is known as the “common enemy doctrine.” (Id. at p. 441.) It “holds that as an incident
to the use of his own property, each landowner has an unqualified right, by operations on
his own land, to fend off surface waters as he sees fit without being required to take into
account the consequences to other landowners, who have the right to protect themselves
as best they can.” (Keys v. Romley (1966) 64 Cal.2d 396, 400.)
          Belair v. Riverside County Flood Control Dist. (1988) 47 Cal.3d 550 (Belair),
represented a change in the analysis of a public entity’s liability in inverse condemnation
where, under Albers, supra, 62 Cal.2d 250, the public entity had a common law right to
inflict damage under the common enemy doctrine. (Belair, supra, at p. 563.) Belair

                                                8
involved a levee failure after a series of heavy storms. (Id. at p. 555.) Belair reasoned
that while strict inverse condemnation liability might not be appropriate in the case of
public flood control improvements, such improvements should not be cloaked with the
same immunity as private flood control measures. (Id. at p. 564.) Belair adopted a rule
of reasonableness in such situations, which balanced public need against the gravity of
private harm. (Id. at p. 566.)
       Belair adopted a rule of reasonableness rather than one of absolute liability
because absolute liability would discourage beneficial flood control improvement, but
would still compensate for losses that were unfairly incurred. (Belair, supra, 47 Cal.3d at
p. 565.)
       The Supreme Court has since followed the Belair rule of reasonableness, refining
its application in Locklin, supra, 7 Cal.4th 327, and Bunch, supra, 15 Cal.4th 432.
       Locklin, supra, 7 Cal.4th at page 337, held that the rule of reasonableness applies
when alterations or improvements on upstream property discharge an increase of surface
water into a natural watercourse, and the increased volume causes downstream property
damage. In Locklin, the plaintiffs owned property that extended into a natural
watercourse. (Id. at pp. 338-339.) The watercourse began carrying more water because
of upstream development, and the larger volume of water eroded the plaintiffs’ property.
(Id. at p. 339.) The plaintiffs sued the City of Lafayette, alleging the failure to maintain
the storm drainage system caused the erosion. (Id. at pp. 339-340.)
       Although Locklin involved a natural watercourse, it made two pronouncements
that are applicable here. First, it stated that a landowner’s conduct in using or altering
property in a manner affecting the discharge of surface waters onto adjacent property is
subject to a test of reasonableness. (Locklin, supra, 7 Cal.4th at p. 351.) This test
provides that “ ‘[n]o party, whether an upper or a lower landowner, may act arbitrarily
and unreasonably in his relations with other landowners and still be immunized from all
liability.’ ” (Ibid.) Second, with the adoption of the reasonable use test for surface

                                              9
waters, there is no valid reason for distinguishing between surface waters and those that
flow through a natural watercourse with respect to the obligations of the respective
owners. (Id. at p. 352.) Locklin held that the rule of reasonableness was applicable in the
discharge of surface waters whether the water is discharged onto the land of an adjoining
owner or into a natural watercourse. (Id. at p. 357.)
       In Bunch, supra, 15 Cal.4th 432, a water district owned flood control facilities
consisting of a levee, dike, and channel, designed to protect property, including the
plaintiffs’ property, from historical flooding. (Id. at p. 437.) The facilities failed during a
tropical storm when floodwater overtopped the dike and levee, leading to the flooding of
the plaintiffs’ property. (Id. at p. 438.) The plaintiffs argued that the rule of
reasonableness should apply only where a party would have been privileged under the
common law common enemy doctrine to divert floodwaters to the property of another.
(Id. at p. 447.) However, the Supreme Court agreed with the Court of Appeal, which
opined that Belair’s rule of reasonableness “applied to all cases involving unintentional
water runoff, whether they involved facilities designed to keep water within its natural
course or designed to divert water safely away from a potentially dangerous natural
flow.” (Bunch, supra, at p. 439.)
       Plaintiffs cite two cases, Yee v. City of Sausalito (1983) 141 Cal.App.3d 917 and
Marin v. City of San Rafael (1980) 111 Cal.App.3d 591, that they claim are “factually
analogous” in support of their argument that the correct standard of liability for cases
involving municipal storm drain improvements is strict liability. They overlook the fact
that the California Supreme Court disapproved both cases in Bunch, supra, 15 Cal.4th at
pages 447-448. In response to the Bunch plaintiffs’ assertion that the applicable standard
should be strict liability because diversion of waters from their natural course was not a
privileged activity at common law, the Supreme Court responded that those cases were
“pre-Belair cases that . . . applied an absolute liability standard to flood control cases
involving the diversion of surface or floodwaters from their natural channel or drainage.”

                                              10
(Id. at p. 447.) The Supreme Court held that the reasonableness rule should be extended
to cases involving the failure of flood control measures designed to divert potentially
dangerous natural water flow. (Id. at p. 449.)
       We thus reject the first part of plaintiffs’ contention--that the rule of
reasonableness applies only where surface waters are discharged into a natural
watercourse or the result of a flood control project for the protection of lands that were
historically subject to flooding. We next consider the second part of plaintiffs’
contention.
       Bunch represents an expansion of the rule of reasonableness set forth in Belair and
Locklin beyond the context of flood control improvements along natural watercourses.
Bunch applied the rule of reasonableness even though the water district had diverted and
rechanneled the water. (Bunch, supra, 15 Cal.4th at p. 447.) However, the plaintiffs’
property had been subject to historical flooding, thus the Birons argue here that Bunch
must be viewed narrowly as holding that the rule of reasonableness applies only if the
plaintiff’s property was historically subject to flooding, and there was no evidence of
historical flooding here.
       Bunch should not be read so narrowly. First, the actual holding was that the
“reasonableness test applies to cases involving public flood control works that cause
physical damage to private property,” and “that courts should use [the Belair and Locklin]
factors in cases where a public entity’s flood control measures, designed to protect
against potentially dangerous periodic flooding, cause property damage.” (Bunch, supra,
15 Cal.4th at p. 454.) Thus, the holding purports to apply more broadly to measures
designed to protect against potential flooding than to measures designed to protect
against historical flooding. Bunch recognizes that it is applying “. . . Belair’s
reasonableness rule to cases involving the failure of flood control measures designed to
divert potentially dangerous natural water flow.” (Id. at p. 449.) The trial court



                                              11
specifically found that the storm drain facilities here are a means of surface water and
flood control.
       Also, Bunch indicated Belair and Locklin are not to be narrowly interpreted. In
response to the Bunches’ argument that the rule of reasonableness should apply only
where the public entity’s actions would have been privileged under common law, Bunch
responded that “Belair warned against limiting application of its rule to cases involving
previously privileged conduct.” (Bunch, supra, 15 Cal.4th at p. 448.) Bunch stated,
“Belair’s dictum indicates that the court believed its analysis could apply to all flood
control cases involving unintended property damage.” (Ibid.)
       In considering inverse condemnation liability, courts must balance the interests of
property owners, who should not be required to contribute more than their fair share to
the public undertaking, with the “possibility that imposing open-ended liability on public
entities charged with creating and maintaining flood control improvements will
discourage the development of needed public works.” (Bunch, supra, 15 Cal.4th at pp.
450, 449.) That a certain harm is foreseeable does not necessarily mean the public entity
is unreasonable in failing to protect against it if the probability, frequency, and magnitude
of the damage is low in relation to the cost and ability to protect against the harm. (Ibid.)
       Bunch predicted the circumstances of this case when it held, “the placement,
design, and construction of even the most effective system inherently involve a complex
balancing of interests and risks. Whatever choice the responsible agency makes will
necessarily affect the patterns of flooding in the event the project fails, and will almost
certainly increase certain risks in order to reduce others. The dangers posed to individual
lands by the failure of any public flood control project are ‘potentially enormous’ and
sometimes deserve compensation. However, strict and ‘open-ended’ liability for the
failure of a project whose overall design, construction, operation, and maintenance was
‘reasonable’ would unduly deter the development of these vital bulwarks against
common disaster. [Citation.] [¶] In the context of inverse condemnation, therefore, a

                                             12
flood control agency does not necessarily exact ‘disproportionate,’ and thus compensable,
contributions from particular landowners simply because it constructs adjacent flood
control improvements that may alter how floodwaters will affect those landowners if the
improvements fail to contain the flow.” (Bunch, supra, 15 Cal.4th at p. 450.)
       The trial court properly concluded that the correct standard in determining City’s
inverse condemnation liability was a reasonableness standard.
B. Trial Court Properly Applied the Reasonableness Standard
       The trial court considered eleven factors in concluding City acted reasonably. The
factors were set forth in Locklin, supra, 7 Cal.4th 327. But, following Locklin, the
Supreme Court and Courts of Appeal most often focus on six factors. (Bunch, supra, 15
Cal.4th at p. 454; Gutierrez v. County of San Bernardino (2011) 198 Cal.App.4th 831,
848; Arreola v. County of Monterey (2002) 99 Cal.App.4th 722, 739; Paterno v. State of
California (1999) 74 Cal.App.4th 68, 83; contra, Skoumbas v. City of Orinda (2008) 165
Cal.App.4th 783, 792.) We find the six Locklin factors to be the most probative of a
determination of reasonableness. These factors are: “ ‘(1) The overall public purpose
being served by the improvement project; (2) the degree to which the plaintiff’s loss is
offset by reciprocal benefits; (3) the availability to the public entity of feasible
alternatives with lower risks; (4) the severity of the plaintiff’s damage in relation to risk-
bearing capabilities; (5) the extent to which damage of the kind the plaintiff sustained is
generally considered as a normal risk of land ownership; and (6) the degree to which
similar damage is distributed at large over other beneficiaries of the project or is peculiar
only to the plaintiff.’ ” (Gutierrez v. County of San Bernardino, supra, at p. 848.)
       We review the court’s factual findings that City acted reasonably under the
substantial evidence standard. (Gutierrez, supra, 198 Cal.App.4th at p. 843.) Plaintiffs
do not claim there was no substantial evidence to support the trial court’s factual
findings. Instead, they argue against the way the trial court applied the rule of



                                              13
reasonableness. “The application of the appropriate legal standard to the facts properly
found by the trial court is a legal question.” (Id. at p. 844.)
       1. Overall Public Purpose
       We agree with the trial court that an important public purpose was served by the
storm drain system, which was constructed to control surface water and flooding. The
system did not fail, but was unable to drain the amount of water entering the system.
Nevertheless, there was a benefit to having some storm drain capacity that would prevent
some flooding.
       2. The Degree to Which Plaintiffs’ Loss is Offset by Benefits
       As the trial court stated, the extent of plaintiffs’ damage is unknown because the
damages phase of the trial was bifurcated. However, plaintiffs undoubtedly have
benefited from the storm drain system, even though it was inadequate in this instance to
prevent flooding to plaintiffs’ property.
       3. Availability to Public Entity of Feasible Alternatives with Lower Risks
       There was evidence that even if funding had been available, the downtown area
was a low priority for an upgrade in capacity because the need was greater elsewhere.
Additionally, the recommended design flow upgrade for most of the facilities at issue was
for a 25-year storm. Even if the upgrades had been made, flooding may have resulted
from the storm in question because it exceeded a 25-year storm.
       4. Severity of Plaintiffs’ Damage in Relation to Risk-Bearing Capabilities
       The trial court concluded plaintiffs could have taken the same steps as the adjacent
property owners to mitigate the risk of flooding, i.e., purchasing flood insurance and
installing floodgates. The trial court concluded that this would not have been an
enormous burden compared to the cost of upgrading the storm drain system to a level that
would have prevented the flooding. We agree.




                                              14
       5. Extent to Which Damage is Normal Risk of Land Ownership
       Any property is subject to some risk for flooding when a particularly strong storm
exceeds the storm drain capacity. The risk may be greater depending on the location and
surroundings of the property. A property at the lowest point of a watershed is more likely
to flood than one at a higher point. Flooding may also depend on the path of uncontained
surface waters as they travel to the lowest point, and whether the property is in that path.
Although there was some normal risk of flooding of the property given its location, the
amount of flooding in this instance may well have been abnormal.
       6. Whether Similar Damage is Distributed at Large or Peculiar to Plaintiffs
       The trial court found that no evidence was presented whether other landowners
suffered damage as a result of the storm. There was evidence that the adjacent property
owner had incurred the expense of protecting his property by installing a brick wall and
floodgates and by purchasing flood insurance. There was no evidence City made a
conscious decision to flood plaintiffs’ property in order to spare other properties.
       The trial court properly applied the rule of reasonableness in this case to conclude
that City acted reasonably in not increasing the capacity of its storm drain system.
C. Substantial Causation
       Although the trial court did not expressly rule that the storm drainage system was
not a substantial cause of the flooding, its findings lead to a conclusion of no substantial
causation. We agree that plaintiffs failed to prove the storm drainage system was a
substantial cause of their damage because the system did not fail, it was simply
overwhelmed by the amount of water the storm deposited into the system.
       Belair recognized that inverse condemnation liability requires a showing of
proximate cause, and “in order to establish a causal connection between the public
improvement and the plaintiff’s damages, there must be a showing of ‘ “a substantial
cause-and-effect relationship excluding the probability that other forces alone produced
the injury.” [Citations.]’ [Citation.]” (Belair, supra, 47 Cal.3d at p. 559.) Belair

                                             15
proceeded to describe the factual scenario here as an example of a situation lacking the
element of substantial causation. Belair stated that where a rainstorm merely contributes
to the injury, proximate cause is established if the injury occurred in substantial part
because the improvement failed to function as intended. (Id. at pp. 559-560.) “The
public improvement would cease to be a substantial contributing factor, however, where
it could be shown that the damage would have occurred even if the project had operated
perfectly, i.e., where the storm exceeded the project’s design capacity. In conventional
terminology, such an extraordinary storm would constitute an intervening cause which
supersedes the public improvement in the chain of causation.” (Id. at p. 560, italics
added.)
        In the present case, the public improvement did operate perfectly, but the storm
exceeded the design capacity. The trial court found that the storm event on February 23,
2009, “overwhelmed the natural watercourse . . . and overwhelmed the storm drain
infrastructure . . . .” This caused surface water to backup onto the adjacent road, Railroad
Avenue, caused the storm drain inlet on plaintiffs’ property to surcharge, and caused
surface water to find the lowest path downstream via Court Street, another adjacent road.
It found that City’s storm drain pipes were operating free of any obstructions. It found
that the storm drain system did not fail, and that it performed as designed on a 10-year
storm design.4 However, the system was overwhelmed with water because the storm was
consistent with a 100-year storm, rather than a 10-year storm.
        The trial court found that plaintiffs did not prove the storm drain system created a
situation or a risk that would not otherwise have been present, nor did they prove that the
storm drain system exposed their property to a risk of flooding that did not otherwise




4   A witness for City testified the facilities were constructed for a 10-year design flow.

                                              16
exist. The court found plaintiffs’ argument to be that the storm drain system simply did
not do enough to protect their property.
       Belair accurately predicted the facts of this case, i.e., the project operated perfectly
but the storm exceeded the project’s design capacity, and concluded that under such facts
the extraordinary storm would be a superseding cause, cutting off the public entity’s
liability for inverse condemnation. (Belair, supra, 47 Cal.3d at p. 559-560.)
       Plaintiffs cite this court’s decision in Akins v. State of California (1998) 61
Cal.App.4th 1, 43-47 (Akins), for the proposition that if the public improvement
contributes to the damage, another concurrent cause such as an extraordinarily large
storm, is not a superseding cause. However, the facts of this case align perfectly with the
description of a superseding cause in Belair and are dissimilar to the facts in Akins. Akins
involved “an intentional use of plaintiffs’ properties as a retention basin, thereby causing
flooding to lands which were arguably not historically subject to flooding, in order to
protect other property. Thus, the fact that design capacity was exceeded would not make
the rainstorm the sole cause of the damage.” (Akins, supra, 61 Cal.App.4th at p. 45.)
Akins was a quintessential inverse condemnation case, because the flood control project
there was designed to flood some properties in order to save others. The fundamental
policy behind the constitutional requirement of just compensation is the consideration
“ ‘ “whether the owner of the damaged property if uncompensated would contribute more
than his proper share to the public undertaking.” In other words, the underlying purpose
of our constitutional provision in inverse -- as well as ordinary -- condemnation is “to
distribute throughout the community the loss inflicted upon the individual . . . .” ’
[Citation.]” (Belair, supra, 47 Cal.3d at p. 558.)
       Akins, supra, 61 Cal.App.4th 1, recognized that an extraordinary storm would
constitute a superseding cause where “accidental flooding from natural forces exceeding
design capacity breach[ed] a project designed to reduce the risk of harm from natural
forces.” (Id. at p. 45.) The situation is analogous to floodwaters overtopping a levee

                                              17
because they exceed the capacity of the levee. (Id. at p. 44.) Here, the storm exceeded
the capacity of the storm drain system, which was constructed to reduce flooding from
rainwater, causing the drains to overflow.
       Nature was a superseding cause of the flooding, and absent proof of substantial
causation, defendant has no liability in inverse condemnation.
                                           II
                          Dangerous Condition of Public Property
       Government Code section 835 provides that a public entity is liable for injury
caused by a dangerous condition of public property if: (1) the property was in a
dangerous condition at the time of the injury, (2) the dangerous condition proximately
caused the injury, (3) the dangerous condition created a reasonably foreseeable risk of the
kind of injury that was incurred, and (4) a public employee acting within the scope of
employment negligently or wrongfully created the dangerous condition, or the public
entity had sufficient notice of the dangerous condition to have protected against it.
       Even if the plaintiff can establish that a dangerous condition of public property
existed, a public entity is not liable for damage from a dangerous condition if the act or
omission that created the condition was reasonable, or if the action the entity took or
failed to take to protect against the risk was reasonable. (Gov. Code, § 835.4.)
Reasonableness is a question of fact for the trier of fact, and is determined by weighing
the probability and gravity of potential injury against the practicability and cost of the
action. (Gov. Code, § 835.4; De La Rosa v. City of San Bernardino (1971) 16
Cal.App.3d 739, 749.)
       The trial court, acting as trier of fact, found that no dangerous condition existed
because neither the storm drain system, nor the decision to defer upgrades to the system
created a substantial risk of injury to members of the general public. The trial court
further found that even if the storm drain system was a dangerous condition, City’s
conduct in not protecting against the risk of injury was reasonable.


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       We review the trial court’s factual findings under a substantial evidence standard.
(Biagini v. Beckham (2008) 163 Cal.App.4th 1000, 1010.) We presume the trial court’s
factual findings are supported by the record. (Akins, supra, 61 Cal.App.4th at p. 36.)
Plaintiffs do not argue that the evidence was insufficient to support the trial court’s
conclusions that neither the storm drain system nor the decision to defer upgrades to the
storm drain system created a substantial risk of injury to the general public, or that City’s
conduct in not protecting against the risk of injury was reasonable. Instead, they merely
argue that City had notice that the storm drain facilities were deficient.
       Plaintiffs completely ignore the fact that the trial court found no liability for a
dangerous condition in part because City was not unreasonable in its decision not to
upgrade the system. The determination of reasonableness required the court to weigh
“the probability and gravity of potential injury to persons and property foreseeably
exposed to the risk of injury against the practicability and cost of taking alternative action
that would not create the risk of injury or of protecting against the risk of injury.” (Gov.
Code, § 835.4, subd. (a).) The issue is, as indicated, one of fact for the trier of fact,
which we review for substantial evidence.
       The 1993 Study indicated City ranked the downtown area (where plaintiffs’
property is located) as the lowest priority because the majority of problems in that area
consisted of nuisance flooding (less than 2 feet deep, with low velocities) in the streets.
The trial court found that the Study estimated the cost of improvements to the deficient
storm drain facilities in the downtown area to be $7.5 million, and the cost for all other
deficient storm drain facilities throughout the city to be approximately $14.6 million, a
finding plaintiffs do not dispute. The trial court also found that in the early 2000’s, City
considered the storm drain utility to be grossly underfunded and lacking in available
funds for improvement of the system, a finding plaintiffs do not dispute.
       Because there was evidence that the risk of injury was small in relation to the cost
of repairs, there was substantial evidence to support the trial court’s conclusion that City

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acted reasonably in its decision not to upgrade the system. Thus, even if the trial court
had concluded the storm drain system was a dangerous condition of public property, there
would be no liability.
                                      DISPOSITION
       The judgment is affirmed. Defendant City shall recover costs on appeal.



                                             BLEASE                    , J.


We concur:


         RAYE                      , P. J.


         BUTZ                      , J.




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