Filed 3/16/21; Certified for Publication 4/14/21 (order attached)

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIFTH APPELLATE DISTRICT

ANTELOPE VALLEY GROUNDWATER CASES*

F082492

LOS ANGELES COUNTY WATERWORKS 

DISTRICT NO. 40 et al.,

Cross-complainants and Respondents,

v.

CHARLES TAPIA, Individually and as Trustee, 

etc., et al.,

Cross-defendants and Appellants;

ANTELOPE VALLEY–EAST KERN WATER 

AGENCY,

Cross-defendant, Cross-complainant and 

Respondent;

U.S. BORAX INC. et al.,

Cross-defendants and Respondents.

(JCCP No. 4408)

OPINION

*Los Angeles County Waterworks District No. 40 v. Diamond Farming Co. (Super. Ct. 

Los Angeles County, No. BC325201); Los Angeles County Waterworks District No. 40 v. 

Diamond Farming Co. (Super. Ct. Kern County, No. S-1500-CV254348); Wm. Bolthouse 

Farms, Inc. v. City of Lancaster (Super. Ct. Riverside County, No. RIC353840); Diamond 

Farming Co. v. City of Lancaster (Super. Ct. Riverside County, No. RIC344436); Diamond 

Farming Co. v. Palmdale Water Dist. (Super. Ct. Riverside County, No. RIC344668); Willis v. 

Los Angeles County Waterworks District No. 40 (Super. Ct. Los Angeles County, 

No. BC364553); Wood v. Los Angeles County Waterworks District No. 40 (Super. Ct. Los 

Angeles County, No. BC391869).
2.

APPEAL from a judgment of the Superior Court of Los Angeles County. Jack 

Komar, Judge.†

Law Offices of Robert H. Brumfield and Robert H. Brumfield III for Crossdefendants and Appellants.

Mary Wickham, County Counsel, Warren R. Wellen, Deputy County Counsel; 

Best Best & Krieger, Eric L. Garner, Jeffrey V. Dunn, Wendy Y. Wang; Lagerlof, 

Thomas Bunn III; Murphy & Evertz, Douglas J. Evertz; Olivarez Madruga Lemieux 

O’Neill, W. Keith Lemieux; and Lynne Patrice McGhee for Cross-complainants and

Respondents.

Richards, Watson & Gershon, James L. Markman, and B. Tilden Kim for Crossdefendant, Cross-complainant and Respondent.

Venable, William M. Sloan, Tyler G. Welti; Ellison, Schneider, Harris & Donlan, 

Christopher M. Sanders; Kuhs & Parker, Robert G. Kuhs, Bernard C. Barmann, Jr.; 

Kronick, Moskovitz, Tiedemann & Girard, Eric N. Robinson, Stanley C. Powell; 

Michael N. Feuer, Los Angeles City Attorney, Joseph Brajevich, Raymond Ilgunas; Law 

Office of LeBeau Thelen, Bob H. Joyce; Zimmer & Melton and Richard Zimmer for 

Cross-defendants and Respondents.

-ooOooIn 1999, the first lawsuits were filed in what ultimately evolved into this 

proceeding known as the Antelope Valley Groundwater Cases (AVGC). The AVGC 

proceeding litigated whether the water supply from natural and imported sources, which 

replenished an alluvial basin from which numerous parties pumped water, was inadequate 

to meet the competing annual demands of those water producers, thereby creating an 

†Retired Judge of the Santa Clara Superior Court, assigned by the Chief Justice pursuant 

to article VI, section 6 of the California Constitution.
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“overdraft” condition.1 A number of the parties asserted that, without a comprehensive 

adjudication of all competing parties’ rights to produce water from the aquifer, and a 

physical solution to regulate future pumping to protect the aquifer, this continuing 

overdraft would negatively impact the health of the aquifer.

One of the competing parties, appellant Charles Tapia, individually and as trustee 

of a trust (jointly, Tapia), claimed he owned land overlying the aquifer. Tapia first 

appeared in the late stages of the AVGC litigation to interpose a claim that he was 

entitled to draw 534.5 acre-feet per year (afy) from the limited supply of water available 

in the aquifer, joining the thousands of entities and people who asserted competing claims 

to draw from the limited available water.

Before Tapia’s first appearance, the Judicial Council had ordered all lawsuits 

consolidated into this single adjudication proceeding, and the trial court had embarked on 

an 11-year process in which it, seriatim, (1) defined the geographical boundaries of the

Antelope Valley Adjudication Area (AVAA) to determine which parties would be 

necessary parties to any global adjudication of water rights, (2) concluded the aquifer 

encompassed within the AVAA boundaries (the AVAA basin) was functionally a single 

1

In the context of an aquifer, “overdraft” occurs when the average annual withdrawals or 

diversions from the aquifer exceed the “safe yield” of a groundwater supply and would lead to 

ultimate depletion of the available supply. (Jordan v. City of Santa Barbara (1996) 46 

Cal.App.4th 1245, 1272.) The “safe yield” is “‘the maximum quantity of water which can be 

withdrawn annually from a ground water supply under a given set of conditions without causing 

an undesirable result.’ The phrase ‘undesirable result’ is understood to refer to a gradual 

lowering of the ground water levels resulting eventually in depletion of the supply.” (City of Los 

Angeles v. City of San Fernando (1975) 14 Cal.3d 199, 278 (San Fernando), disapproved on 

other grounds in City of Barstow v. Mojave Water Agency (2000) 23 Cal.4th 1224, 1248

(Barstow).) In essence, safe yield examines the available groundwater recharge from 

replenishing sources such as native precipitation and associated runoff, along with return flows 

from such sources, less losses incurred through natural groundwater depletions such as 

subsurface outflow or evaporative losses. (San Fernando, supra, at pp. 278–279; see TehachapiCummings County Water Dist. v. Armstrong (1975) 49 Cal.App.3d 992, 996, fn. 3 (TehachapiCummings) [“Natural ‘safe yield’ is the maximum quantity of ground water, not in excess of the 

long-term, average, natural replenishment (e.g., rainfall and runoff), which may be extracted 

annually without eventual depletion of the basin”].)
4.

aquifer, and (3) found the AVAA basin was in a state of chronic overdraft because 

extractions exceeded the basin-wide annual safe yield by a considerable margin.

The next phase (“Phase 4”), which also occurred before Tapia’s first appearance, 

quantified how much water was currently being pumped by the participating competing 

water rights claimants. The court ultimately determined the annual “baseline” amounts 

actually extracted by the largest of the competing parties with claims to water from the 

aquifer. These annual extractions confirmed the amounts annually extracted were 

substantially in excess of the safe yield for the AVAA basin.

The next phase, which contemplated trial of the issues of federal reserved water 

rights and imported water return flow rights, was interrupted by settlement discussions. 

These discussions ultimately produced an agreement among the vast majority of parties 

in which they settled their competing groundwater rights claims and agreed to support the 

contours of a proposed plan (the “Physical Solution”) designed to bring the AVAA basin 

into hydrological balance. The Physical Solution included limits on pumping that would 

bring total annual extractions from the aquifer into balance with the available “native safe 

yield” (sometimes, NSY). Accordingly, among the provisions of the proposed Physical 

Solution was an agreement by most of those who had demonstrated their extant pumping 

from the aquifer during the Phase 4 baseline period, as follows: (1) to substantially

reduce their water extractions to a level that would match their assigned allocation of 

water from the NSY, and (2) to pay for imported water for any extractions above their 

assigned allocation.

Tapia was not among the settling parties. Accordingly, before considering 

whether to approve the Physical Solution (including the proposed global allocation of 

water from the NSY) for the AVAA basin, the court conducted a separate trial on Tapia’s 

unsettled claims and defenses, including (1) the extent to which various public water 

suppliers (sometimes, PWS) had obtained prescriptive rights in the NSY as to Tapia and 

others, and (2) whether Tapia had demonstrated his entitlement to an allocation from the 
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NSY based on Tapia’s showing of how much he pumped for reasonable and beneficial 

uses on his land. The court found the PWS had established prescriptive rights in the NSY 

as to Tapia, and that Tapia had not adequately shown a basis for his requested allocation 

of water under the Physical Solution.

In addition to resolving Tapia’s unsettled claims, the court held a trial on the 

rationale for and efficacy of the proposed Physical Solution. The court found the 

proposed Physical Solution was reasonable, fair and beneficial as to all parties, and 

served the public interest, and approved the Physical Solution.

Tapia’s claims on appeal are murky, but it appears Tapia interposes three claims: 

(1) the Physical Solution violates California water rights priorities because it allocates 

portions of the NSY to the public water suppliers while denying Tapia his claimed 

allocation of that NSY; (2) the Physical Solution is inequitable because overlying owners 

with demonstrable existing pumping were allocated proportionate shares of the remaining 

NSY while Tapia, despite similarly showing existing pumping, did not receive a 

proportionate share; and (3) the Physical Solution violates the constitutional requirement 

that available water be applied to reasonable and beneficial uses. We conclude 

substantial evidence supports the judgment as to Tapia, and that the Physical Solution 

comports with California law governing water priorities and the constitutional 

“reasonable and beneficial use” requirement. Accordingly, we will affirm the judgment 

as to Tapia.

I

FACTUAL AND PROCEDURAL HISTORY

A. Factual Setting

The AVAA encompasses a vast desert area of over a thousand square miles. As of 

2005, it was home to over 450,000 people, with substantial projected population growth 

in the future. It is also home to Edwards Air Force Base, making the United States the 

AVAA’s largest single landowner. Its regional economy, while historically rooted in 
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agricultural operations, has been shifting to include increased residential communities, as 

well as industrial and mining operations.

The principal source of water supporting all of these uses is the aquifer underlying 

the AVAA. The aquifer underlying the AVAA was in a state of chronic “overdraft,” 

meaning that extractions from the aquifer have exceeded the amount of water 

replenishing that aquifer by significant margins. It had been in overdraft for decades 

before the current litigation commenced in 1999. The overall water levels within the 

AVAA basin were declining, and declining water levels have caused significant longterm damage, including subsidence and lost aquifer storage capacity. The estimated 

average annual safe yield from all sources of recharge (natural sources such as 

precipitation, external sources such as imported water, and return flows) was 110,000 afy 

for the AVAA basin, but the numerous parties who pumped water from that basin were 

annually extracting an estimated 130,000 to 150,000 afy.

B. The Competing Water Use Claimants

1. The Public Water Suppliers

The PWS are a group of agencies and special districts formed to supply water to 

their customers. Los Angeles County Waterworks District No. 40 (District 40), the 

largest of these entities, is the largest urban water supplier for the region’s cities, and it 

pumps from the aquifer to supply water to over 200,000 people within the AVAA, 

primarily for residential uses. Other public water entities occupying roles similar to 

District 40 included Palmdale Water District, Littlerock Creek Irrigation District, Palm 

Ranch Irrigation District, and Quartz Hill Water District. District 40 also purchases 

water from the State Water Project, which is imported into the AVAA and supplements 

the basin’s native safe yield.

2. The Federal Government

The United States owns approximately 300,000 acres overlying the AVAA basin 

and operates Edwards Air Force Base on those lands. The United States claimed federal 
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reserved water rights of up to 11,500 afy for military purposes distinct from any 

correlative rights it had as an overlying landowner.

3. The Overlying Landowners Presently Using Groundwater

There are multiple categories of owners of overlying land who, collectively, 

extract the majority of the AVAA basin’s water.

There are numerous individual persons or entities who own overlying land and 

who demonstrated the extent to which they extracted water for use on that land. This 

group includes corporate landowners, which extracted water to supply their farming and 

mining operations on their owned land, along with numerous other individual landowners 

(with varying levels of and purposes for water used on their land) who compete for the 

NSY. Tapia owns overlying land (a 137-acre property) and claimed that, during the 

baseline period, his well extracted an average of 534.5 afy from the aquifer to irrigate a 

farm on that property.

There were also numerous “mutual water companies,” which were formed when 

the owners of overlying land incorporated the mutual water company and transferred 

their water rights to the company in exchange for stock and the right to receive water 

deliveries from the mutual water company. Another large category of overlying 

landowners currently pumping from the aquifer for use on their property were the 

members of the “Small Pumper (or Wood) Class.” The class, after opt outs, ultimately 

represented over 3,000 privately owned parcels that fell within the class definitions. The 

class represented the interests of private landowners who had pumped less than 25 afy on 

their property during any year from 1946 through 2015. Finally, the overlying 

landowners currently pumping from the aquifer for use on their property included several 

public entities and agencies.

4. Overlying Landowners Not Presently Using Groundwater (the 

“Willis Class”)

The Willis Class was formed to represent the interests of approximately 18,000 

private individuals or entities (with certain exceptions) that owned overlying land in the 
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AVAA but who had not commenced extracting water from the aquifer during the five 

years prior to January 18, 2006.

II

THE LITIGATION

A. The Litigation Commences

Between late 1999 and early 2001, the first lawsuits (which ultimately evolved 

into the AVGC) were filed by Diamond Farming Company and Wm. Bolthouse Farms, 

Inc., concerning competing water rights in the aquifer. These actions, styled as quiet title 

actions against various public water suppliers, sought a determination of the various 

rights and priorities of overlying landowners and others claiming the right to extract 

water from the AVAA basin. In 2004, District 40 filed its actions seeking (1) a 

comprehensive determination of the water rights of the thousands of persons, companies, 

public water suppliers, public agencies and the federal government, and (2) a physical 

solution to alleviate the overdraft conditions in the AVAA and to protect the AVAA 

basin. Among other claims, District 40 sought declaratory relief that it had obtained 

prescriptive rights to water from the aquifer, and that the water rights held by all other 

defendants (except other public entities) were subordinate to the PWS’s prescriptively 

acquired rights.

After the Judicial Council granted District 40’s petition to coordinate all of the 

then pending actions, the court requested that District 40 refile its action as a first 

amended cross-complaint in the now coordinated proceedings. Accordingly, in early 

2007, District 40 (along with numerous other public water suppliers joining District 40 as 

cross-complainants), filed a cross-complaint seeking (among other things) a 

determination against all overlying landowners within the AVAA that the PWS crosscomplainants had obtained prescriptive rights to certain amounts of water from the 

aquifer, and that the water rights held by all other parties (except other public entities) 

were subordinate to those prescriptively acquired rights. The parties named as cross-
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defendants included numerous specifically named parties, and also included Roe 

defendants who owned real property within the boundaries of the AVAA and extracted 

water or claimed some right, title, or interest to water located within the AVAA, or who 

asserted claims adverse to the PWS’s rights and claims, but whose names were then 

unknown to the PWS.

Tapia was ultimately named and added as a party to the PWS cross-complaint as 

Roe 568 by a July 2007 amendment to the cross-complaint. In late 2010, the PWS sought 

entry of Tapia’s default, and Tapia’s default was entered in 2012.

B. Phase 1: Determining the Geographic Boundaries of AVAA

The trial court segmented the various issues raised by the actions and held trials on 

these issues in phased proceedings. In October 2006, the court conducted trial to 

establish the jurisdictional boundaries for the AVAA in order to ascertain which parties 

and entities with claims to the groundwater would be necessary parties in the litigation, as 

either overlying owners with usufructuary rights in or as appropriators producing water 

from the aquifer, so that a comprehensive adjudication of all claims could be made in 

later proceedings. The court established the “basic” jurisdictional boundaries for the 

AVAA as largely coextensive with the boundaries of the alluvial basin as defined by the 

Department of Water Resources’ bulletin 118.

C. Phase 2: Determining Hydraulic Connectivity Within AVAA 

Boundaries

In the second phase, the court heard evidence to assess the hydrologic nature of 

the aquifer within the geographical boundaries set for the AVAA, and specifically 

evaluated whether there were any distinct subbasins within the AVAA basin that lacked 

any hydrologic connection such that they should be treated as separate, unconnected 

basins for purposes of adjudication. The court concluded there was sufficient hydraulic 

connectivity within the AVAA basin as a whole to obviate any claim that certain sections 

should be treated as separate basins.
10.

D. The Consolidation Order

In 2009, the PWS moved to transfer and consolidate all pending actions and crossactions. The PWS asserted that all the actions sought resolution of the same core issue: 

the determination of water rights in a single aquifer where similar claims for declaratory 

relief, resolution of overlying and prescriptive rights, and imposition of a physical 

solution required that a single judgment be entered as to all of the actions. The court 

granted the motion and entered its order consolidating all but one of the pending actions 

and cross-actions, noting that all claimed water rights in the aquifer were correlative to all 

other competing claims to water from the aquifer, a determination of any individual 

party’s water right cannot be decided “in the abstract but must also take into 

consideration all other water rights within [the] single aquifer,” and therefore all pending 

actions shared common issues of law and fact on the relative rights to draw water from 

the aquifer.

E. Phase 3: Determining Safe Yield and Overdraft

The Phase 3 trial litigated the safe yield for the AVAA basin and whether the area 

encompassed within the AVAA was in overdraft. The court found the basin was in a 

state of overdraft and that average extractions had significantly exceeded average 

recharge for decades, causing a steady lowering of water levels and accompanying 

subsidence since 1951. The court concluded the average total safe yield from all sources 

was 110,000 afy for the AVAA as a whole, while current actual extractions from the 

AVAA as a whole (ranging between 130,000 and 150,000 afy) exceeded average annual 

recharge. Accordingly, the court found (1) the AVAA was in overdraft and (2) the 

annual safe yield was a total of 110,000 afy.

The total annual safe yield ultimately set by the court in this phase as the

appropriate “quantity of pumping from the basin [which] will maintain equilibrium in the 

aquifer” appears to have amalgamated two different components: amounts attributable to 

“native” water and amounts attributable to “imported” water. Various experts testified 

that native water additions (i.e., water coming into the basin from precipitation and 
11.

runoff) provided new water to the AVAA basin ranging between 55,000 to 68,000 afy. 

When “return flows” from that native new water were calculated, the PWS contended the 

native safe yield should be set at approximately 82,300 afy for the AVAA basin as a 

whole. However, various entities also imported additional water into the AVAA, and 

when that imported water (along with its return flows) was added to the native supply, the 

total safe yield for the AVAA basin was determined by the court to be 110,000 afy.

F. Phase 4: Determining Actual Groundwater Production by Claimants

In the next phase, the court ultimately concluded it would limit trial to 

individualized determinations of how much water various claimants actually pumped 

from the AVAA basin during the years 2011 and 2012. Based on the stipulations and 

evidence presented by numerous parties about the amounts pumped during the relevant 

time frames, the court determined how much water the various major stakeholders 

actually pumped from the AVAA basin in the relevant years. The amounts actually 

pumped during those sample years exceeded the previously determined safe yield. The 

court found that, during the sampled years, the parties cumulatively pumped in excess of 

120,000 afy even before consideration of the amounts pumped by the Small Pumper

Class, and apparently without consideration of the amount that would be subject to any 

federal reserved right.

G. Phase 5: Federal Reserved Rights and Imported Water Return Flow 

Rights

The “Phase 5” trial bifurcated two issues (federal reserved water rights, and any 

claimed rights to recapture and use any return flows from water imported into the 

AVAA) for the next trial phase. However, during the evidentiary presentations, the 

parties requested a recess of pending proceedings to permit further settlement 

discussions. The parties then met and conducted settlement discussions and, in April 

2014, the parties informed the court that the vast majority of the parties had reached a 

proposed global settlement of their respective groundwater claims. This proposed global 

settlement included agreement on the contours of a basin-wide groundwater management 
12.

plan to implement a physical solution to the AVAA basin’s overdraft conditions, which 

included an allocation of the available native safe yield among the parties competing for 

that native safe yield.

The parties to the proposed settlement, recognizing that several appearing parties 

and nonparticipating parties had not agreed to the settlement, proposed a case 

management schedule for resolving all remaining unsettled claims and to approve the 

proposed settlement. Shortly thereafter, Tapia sought and obtained an order setting aside 

his default and permitting him to file an answer to the public water suppliers’ crosscomplaint.

H. The Final Phase: Trial on the Unresolved Claims and Proposed 

Physical Solution

Because several parties with potential claims to groundwater (including Tapia) had 

not joined in the proposed global settlement and physical solution, the court scheduled 

hearings for the fall of 2015 (1) to litigate the unresolved claims by parties who did not 

join in the settlement,

2 and (2) to consider whether to adopt the proposed Physical 

Solution. Tapia’s claim was among the remaining claims to be resolved before any final 

judgment could be entered, and the claim required trial on whether the public water 

suppliers had obtained prescriptive rights as against all nonsettling parties (including 

2

In the spring of 2015, the settling parties and a number of the nonsettling parties, 

including Tapia, agreed on a process by which any nonsettling parties would “prove up” their 

claims to a portion of the NSY. The parties ultimately participating in this prove-up process 

submitted briefs and supporting evidence to demonstrate the basis for their claim to an allocation 

of production rights from the NSY. For example, a mobilehome park submitted evidence (based 

on well logs, meter readings and annual reports to the State Water Resources Board) that their 

average annual production for the sample period was approximately 148 afy. Based on that 

evidence, the court ultimately found the mobilehome park had demonstrated the extent to which 

it reasonably and beneficially used water and granted the mobilehome park a production right of 

64 afy. The court similarly found other of these claimants had shown through this prove-up 

process that they (1) owned overlying land, (2) had demonstrated the amounts of water they 

pumped for reasonable and beneficial uses on their land, and (3) were entitled to certain 

“production rights” under the Physical Solution.
13.

Tapia), and whether Tapia and any other nonsettling party had established the amounts of 

water they pumped for reasonable and beneficial uses for their overlying property.

1. Evidence on Tapia’s Water Usage

Tapia asserted during the prove-up proceedings he was entitled to production 

rights from the native safe yield of 534.5 afy because that was the amount he averaged 

during the 2011 and 2012 “baseline” years for use on his overlying property. At trial, 

Tapia testified he grew corn and pumpkins on roughly 100 acres of his Rosamond farm 

during 2011 and 2012, which he irrigated with pumped water using a sprinkler system. 

He had used imported water (purchased from the Antelope Valley—East Kern Water 

Agency) prior to 2009, but thereafter installed a pump that began operating in 2009. 

Tapia estimated his water usage for 2011 and 2012 by extrapolation from his electrical 

bills from 2011 and 2012. Tapia cited to a “well test,” which showed it required 581 

kilowatt hours to produce one acre-foot of water from his well. He also submitted his 

electrical bills from Southern California Edison for the years 2011 and 2012 showing 

total electrical consumption for those years, from which he extrapolated he had used 

517.4 acre-feet in 2011 and 551.6 acre-feet in 2012.

However, at trial, Tapia did not testify as to what portion of the water he pumped 

during the baseline years was used to irrigate his owned lands, and admitted that some of 

the water he pumped was used to irrigate adjoining land. He also admitted he did not 

submit records from the water meter on his well to support his claimed amounts. Instead, 

he relied solely on electricity billings to estimate how much water he pumped for those 

years, but the evidence showed the electrical meter was not a dedicated meter solely for 

the well, but instead was also measuring electricity he consumed for uses on his farm 

other than for operating the well.

The court also heard expert testimony from Robert Beeby, an agricultural engineer 

with expertise in “crop duties.” A “crop duty” is the amount of water required to produce 

a particular crop under prevailing climate and other conditions (wind, temperature, soil 
14.

conditions, etc.) and the requisite growing season. Beeby explained some crops, such as 

alfalfa, have a higher crop duty (i.e., require more water per acre farmed) than other crops 

such as carrots or onions.

Beeby analyzed Tapia’s claimed water use and opined it was “overstated” and “far 

in excess of what they can use based on the crops they reportedly grew.” Beeby’s 

opinions were based on (1) his knowledge of crop duties for the sweet corn and pumpkins 

that Tapia said he grew on the farmed acres, (2) his review of satellite imaging showing 

what portions of Tapia’s farm were actually being irrigated during certain years, and (3) 

his review of Tapia’s pesticide permit applications showing substantially less acreage 

was being farmed by Tapia.

2. Evidence on the PWS Prescriptive Rights

The PWS introduced extensive evidence supporting their claim to prescriptively 

acquired water rights. The PWS submitted records showing historical pumping and 

water use during the time the aquifer was in a state of chronic overdraft, along with 

extensive testimony on the decades-long public notoriety of the overdraft conditions and 

their negative impacts on the area. The court ultimately found in favor of the PWS’s 

prescriptive claims because the evidence showed their adverse use was continuous, open 

and notorious, and under claim of right.

3. Evidence on the Physical Solution

The court also heard evidence from numerous experts concerning the efficacy of 

the proposed Physical Solution. Dr. Dennis Williams, an expert with extensive 

experience with groundwater hydrology, opined the proposed Physical Solution would 

bring the AVAA basin back into balance because of its component parts: the requirement 

that existing users substantially reduce (or “rampdown”) their water consumption during 

the rampdown period, the importation of supplemental water, and the management and 

monitoring provisions of the newly created watermaster for the AVAA. Charles Binder, 

a civil engineer who acted as a watermaster for another watershed, similarly testified the 
15.

provisions of the judgment and proposed Physical Solution would bring the AVAA basin 

back into hydrologic balance.

Two other experts opined the parties who were presently using water, and who had 

allocations of portions of the NSY under the proposed Physical Solution, were reasonably 

using the water they extracted and devoting it to beneficial purposes. Beeby prepared a 

detailed spreadsheet for over 100 water users listing their pre-rampdown average yearly 

pumping, the range of acres to which the water was applied, and identifying the claimed 

beneficial use for that water: irrigation, agriculture, municipal/industrial, domestic, 

reclamation, and wildlife habitat. He opined the historical amounts pumped by most 

overlying landowners did not appear to exceed the reasonable crop duties or other applied 

duties for the type and extent of the listed uses. He also opined that, once water usage 

was “ramped down” to the final levels of overlying production rights assigned to these 

landowners under the Physical Solution, the overliers would have to alter their farming 

practices (either by reducing the acreage farmed or switching to crops with a lower crop 

duty) or import more water, because their ramped-down usage levels would be 

insufficient to continue farming their entire acreage with crops they historically produced. 

A second expert also reviewed the materials documenting the amounts of water 

historically used by the various parties and types of uses to which they devoted that 

water, and compared their historical use to the post-rampdown production rights under 

the proposed Physical Solution. He also developed a list of the categories of beneficial 

uses recognized under applicable California regulatory law and compared that list to the 

common uses of water within the AVAA. Based on that comparison, the expert opined 

the historical uses by the parties to the Physical Solution were recognized beneficial uses 

under applicable California law, and that the amount of water used for those beneficial 

purposes fell within the appropriate parameters.
16.

I. The Final Judgment and Adoption of the Physical Solution

The court’s final judgment, which incorporated determinations from prior phases, 

found the collective demands by those holding water rights in the AVAA basin exceeded 

the available safe yield for the basin, and that a comprehensive adjudication of all of the 

water rights within the AVAA basin and a water resource management plan were

required to prevent further depletion of and damage to the AVAA basin. The court found 

the United States had produced substantial evidence establishing its federal reserved 

water right, and that the PWS had produced substantial evidence showing they had 

acquired a prescriptive right to pump approximately 32,000 afy as against those parties 

who had not joined in the stipulated judgment, including Tapia.

The court further found the Physical Solution properly allocated production rights 

from the NSY to various overlying landowners and public overliers because those 

receiving production rights had established (1) they possessed overlying rights to the 

basin’s NSY by producing evidence of their ownership of overlying lands and the 

amounts of the basin groundwater they actually used, (2) the water they had used were 

reasonable and beneficial uses of such water, (3) the total amounts they had historically 

used exceeded the total NSY, and (4) the amounts they were allocated under the Physical 

Solution represented a severe reduction of their historical reasonable and beneficial uses 

and would be applied reasonably and beneficially.

However, the court found Tapia had not proved his groundwater use because the 

evidence and testimony presented by Tapia was not credible, and accordingly, “the Court 

cannot make a finding as to what amount of water was used on the Tapia Parties’ land for 

reasonable and beneficial use. Therefore, the Tapia parties failed to establish rights to 

groundwater pumping based on the evidence and there is no statutory or equitable basis 

to give them an allocation of water under the physical solution. The Tapia Parties will be 

subject to the provisions of the Physical Solution.”

The court found that, because the NSY was well below the amounts used for 

reasonable and beneficial purposes by those with overlying, prescriptive or reserved 
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rights, it was necessary to allocate and limit production in the NSY among these rights 

holders to protect the basin for existing and future users. The court concluded the 

evidence presented during Phases 4 and 6 supported the conclusion that the Physical 

Solution, which required rights holders to severely reduce the amount of water they used 

and created an overarching water management plan for the basin, fairly allocated the 

available water supplies and made the maximum reasonable and beneficial use of the 

NSY in a manner that would protect the AVAA basin for existing and future users while 

preserving the ability of existing rights holders to continue using the available NSY.

The Physical Solution allocated annual overlying production rights in the NSY 

among the United States, the competing overlying landholders currently extracting water,

and the PWS.3 The Physical Solution did not allocate any specific amount of the NSY to 

Tapia. Instead, it specified any future pumping by Tapia would be governed by the terms 

of the Physical Solution.

The court issued its judgment and adopted the Physical Solution, and issued a 

statement of decision explaining the basis for its judgment and Physical Solution. Tapia 

timely appealed.

III

SUMMARY OF CONTENTIONS ON APPEAL

Tapia appears to raise three claims of error. First, Tapia contends the Physical 

Solution violates California water law principles because it (1) transgressed California’s 

established water rights priorities by assigning production rights to lower priority 

3For existing overlying rights holders who currently produced water from the aquifer, the 

judgment listed their pre-rampdown production and the production right assigned to them (both 

in afy and as a percentage of the production from the adjusted native safe yield). Under the 

Physical Solution, the existing producers were subject to the rampdown provisions, which 

created a seven-year period in which these producers were required to reduce their water 

extractions from their pre-rampdown production to their assigned production right. During the 

first two years, these producers could extract up to their pre-rampdown production without 

paying any replacement assessment, and thereafter were required to reduce their production (in 

equal increments) over the next five years to reduce usage to their assigned production right, and 

any water extractions above those limits would be subject to a replacement assessment.
18.

claimants (the PWS) while denying production rights to Tapia as a higher priority

claimant, and (2) it permanently eliminated Tapia’s vested rights to future uses of the 

NSY. Second, Tapia argues the Physical Solution violates a cardinal constitutional 

requirement—that water be put to reasonable and beneficial uses to the fullest extent 

possible—because various elements of the Physical Solution or judgment are 

incompatible with that requirement. Finally, Tapia asserts it was error to deny him the 

right to produce 534.5 afy of water because the court erroneously deemed his evidence 

insufficient to show the extent and reasonableness of his water use.

IV

OVERVIEW OF APPLICABLE CALIFORNIA LAW

A. Sources of Water Rights

California has been described as having a “dual system of water rights” that

recognizes two principal sources by which water rights in surface waters can be acquired: 

by “riparian rights” holders who have first priority to the available water for riparian 

uses, or by “appropriation” of water for nonriparian uses when there is water in surplus 

beyond that used by first priority users. (See generally Santa Barbara Channelkeeper v. 

City of San Buenaventura (2018) 19 Cal.App.5th 1176, 1183.)

“Similar principles govern rights to water in an underground basin. First 

priority goes to the landowner whose property overlies the groundwater. 

These ‘overlying rights’ are analogous to riparian rights in that they are 

based on ownership of adjoining land, and they confer priority. [Citation.] 

Surplus groundwater also may be taken by an appropriator, and priority 

among ‘appropriative rights’ holders generally follows the familiar 

principle that ‘“the one first in time is the first in right.”’ ([Barstow, supra, 

23 Cal.4th] at p. 1241.) With groundwater there is an exception, however, 

that gives rise to a third category of rights.[4] Under certain circumstances, 

an appropriator may gain ‘prescriptive rights’ by using groundwater to 

4While water rights in an underground basin are typically categorized as overlying, 

appropriative or prescriptive, an additional priority claim to such water, known as “federally

reserved water rights,” can arise when the federal government had reserved land from the public 

domain and dedicates it for a specified purpose, like a military base. (Cf. Cappaert v. United 

States (1976) 426 U.S. 128, 138.)
19.

which it is not legally entitled in a manner that is ‘“actual, open and 

notorious, hostile and adverse to the original owner, continuous and 

uninterrupted for the statutory period of five years, and under claim of 

right.”’ (Ibid.)” (Santa Barbara Channelkeeper v. City of San 

Buenaventura, supra, at p. 1184.)

The priority rights held by overliers is a correlative interest: it is shared along 

with all of the other overlying landowners above the aquifer. (Barstow, supra, 23 Cal.4th 

at p. 1241.) Because it is a shared right, the interest of any specific individual overlier is 

cabined by the interests of all other correlative right holders: “‘as between the owners of 

land overlying strata of percolating waters, the rights of each to the water are limited, in 

correlation with those of others, to his “reasonable use” thereof when water is insufficient 

to meet the needs of all.’” (Central & West Basin Replenishment Dist. v. Southern Cal.

Water Co. (2003) 109 Cal.App.4th 891, 906.) While overliers are entitled to extract 

groundwater from the aquifer for the reasonable and beneficial use of their property (see 

Katz v. Walkinshaw (1903) 141 Cal. 116, 136), when the native supply “is insufficient, 

each is limited to his proportionate fair share of the total amount available based upon 

his reasonable need.” (Tehachapi-Cummings, supra, 49 Cal.App.3d at p. 1001, italics

added.) This correlative overlying right, which is appurtenant to ownership of the 

overlying land, is superior to claims of other persons whose claim lacks equivalent legal 

priority. (Barstow, supra, at p. 1240.)

California recognizes a second type of usufructuary interest in water, described as 

“appropriative rights,” which is the right to take and use “surplus” water for uses outside 

the overlying land. An appropriative right, which “‘depends upon the actual taking of 

water’” (Barstow, supra, 23 Cal.4th at p. 1241), applies only when there are surplus 

waters available by permitting a party to take “‘[a]ny water not needed for the reasonable 

beneficial use of those having prior rights [to] be appropriated on privately owned land 

for non-overlying use, such as devotion to public use ....’” (Ibid.) “‘Proper overlying 

use, however, is paramount and the rights of an appropriator, being limited to the amount 

of the surplus [citation], must yield to that of the overlying owner in the event of a 
20.

shortage, unless the appropriator has gained prescriptive rights through the [adverse, 

open and hostile] taking of nonsurplus waters.’” (Barstow, at p. 1241, italics added.)

As Barstow cautions, California recognizes another type of priority claim to 

available groundwater supplies: prescriptively acquired rights. (City of Santa Maria v. 

Adam (2012) 211 Cal.App.4th 266, 278 (Santa Maria).) Although an appropriator is 

entitled to take any surplus groundwater that the overlying landowners do not need, the 

appropriator is limited to taking only the remainder (or surplus) of the basin’s “safe 

yield.” (Id. at p. 279, citing San Fernando, supra, 14 Cal.3d at p. 214.) As the Santa 

Maria court explained:

“When total extractions exceed the safe yield the basin is said to be in 

overdraft. [Citation.] [¶] ... Prescriptive rights arise when an appropriator 

continues to pump water during times of overdraft. ‘An appropriative 

taking of water which is not surplus is wrongful and may ripen into a 

prescriptive right where the use is actual, open and notorious, hostile and 

adverse to the original owner, continuous and uninterrupted for the 

statutory period of five years, and under claim of right.’” (Santa Maria, 

supra, at p. 279, quoting California Water Service Co. v. Edward 

Sidebotham & Son (1964) 224 Cal.App.2d 715, 726.)

When a nonoverlier’s use of groundwater has ripened into a prescriptively acquired 

interest, the “[a]cquisition of [that] prescriptive right in groundwater rearranges water 

rights priorities among water users, elevating the right of the one acquiring it above that 

of an appropriator to a right equivalent in priority to that of a landowner.” (Santa Maria, 

at p. 297, citing San Fernando, supra, at p. 293.)

B. The “Reasonable and Beneficial Use” Overlay

An overlay to this California system for defining water rights is a key limiting 

principle: the rule of reasonableness. (Santa Barbara Channelkeeper v. City of San 

Buenaventura, supra, 19 Cal.App.5th at p. 1184.) A fundamental precept of California 

water law, embodied in article X, section 2 of the California Constitution, is “that the 

water resources of the State be put to beneficial use to the fullest extent of which they are 

capable, and that the waste or unreasonable use or unreasonable method of use of water 
21.

be prevented, and that the conservation of such waters is to be exercised with a view to 

the reasonable and beneficial use thereof in the interest of the people and for the public 

welfare.” This overarching consideration applies to all water users, regardless of the 

source from which their rights are grounded (Peabody v. City of Vallejo (1935) 2 Cal.2d 

351, 383), because no party has a protectable interest in the unreasonable use of water. 

(Barstow, supra, 23 Cal.4th at pp. 1241–1242.)

The rule of reasonableness means that paramount rights holders, while entitled to 

priority for water devoted to their reasonable and beneficial uses, may not be so 

profligate with their uses of available water that they deprive others of water that would 

otherwise be “surplus” and hence available for appropriation. As articulated by City of 

Pasadena v. City of Alhambra (1949) 33 Cal.2d 908, 925–926:

“[I]t is now clear that an overlying owner or any other person having a legal 

right to surface or ground water may take only such amount as he 

reasonably needs for beneficial purposes. [Citations.] Public interest 

requires that there be the greatest number of beneficial uses which the 

supply can yield, and water may be appropriated for beneficial uses subject 

to the rights of those who have a lawful priority. [Citation.] Any water not 

needed for the reasonable beneficial uses of those having prior rights is 

excess or surplus water ... [which] water may rightfully be appropriated on 

privately owned land for nonoverlying uses, such as devotion to a public 

use or exportation beyond the basin or watershed.”

C. Principles for Court Adjudications of Water Rights Disputes

Where a dispute arises between parties who interpose competing claims to extract 

water from an overdrafted underground basin, the parties may submit their dispute to a 

court to adjudicate and impose a “physical solution” that equitably allocates the available 

water in accordance with California’s laws governing water rights. (Barstow, supra, 23 

Cal.4th at p. 1233.) “The phrase ‘physical solution’ is used in water rights cases to 

describe an agreed-upon or judicially imposed resolution of conflicting claims in a 

manner that advances the constitutional rule of reasonable and beneficial use of the 

state’s water supply.” (Santa Maria, supra, 211 Cal.App.4th at p. 287.) Physical 

solutions are employed “to alleviate overdrafts and the consequential depletion of water 
22.

resources in a particular area” (California American Water v. City of Seaside (2010) 183 

Cal.App.4th 471, 480) and requires the court to apply “general equitable principles to 

achieve practical allocation of water to competing interests so that a reasonable 

accommodation of demands upon a water source can be achieved.” (Imperial Irrigation 

Dist. v. State Wat. Resources Control Bd. (1990) 225 Cal.App.3d 548, 572.)

Although “a trial court may impose a physical solution to achieve a practical 

allocation of water to competing interests, the solution’s general purpose cannot simply 

ignore the priority rights of the parties asserting them. [Citation.] In ordering a physical 

solution, therefore, a court may neither change priorities among the water rights holders 

nor eliminate vested rights in applying the solution without first considering them in 

relation to the reasonable use doctrine.” (Barstow, supra, 23 Cal.4th at p. 1250.) Thus, a 

court may employ equitable apportionment principles to allocate the available supply 

among competing claimants with equivalent priorities, as long as that physical solution 

does not “wholly disregard[] the priorities of existing water rights in favor of equitable 

apportionment ... [and] adequately consider[s] and reflect[s] the priority of water rights 

in the basin” (id. at pp. 1247–1248) and does not “violate the constitutional principle that 

requires water be put to beneficial use to the fullest extent possible” (id. at p. 250).

Ultimately, “[e]ach case must turn on its own facts, and the power of the court 

extends to working out a fair and just solution, if one can be worked out, of those facts.” 

(Rancho Santa Margarita v. Vail (1938) 11 Cal.2d 501, 560–561.)

V

STANDARDS OF REVIEW

When a trial court exercises its equitable powers to adopt a physical solution, our 

review of that judgment is constrained by the deferential abuse of discretion standard of 

review. (Barstow, supra, 23 Cal.4th at p. 1256.) We must begin with the “most 

fundamental rule of appellate review ... that a judgment is presumed correct, all 

intendments and presumptions are indulged in its favor, and ambiguities are resolved in 
23.

favor of affirmance.” (Santa Maria, supra, 211 Cal.App.4th at p. 286 [standard of 

appellate review for trial court judgment adopting a physical solution following trial 

court’s groundwater rights determination].) When “[a] trial court exercises its equitable 

powers in approving a physical solution and entering the judgment, ... review of that 

judgment is under the abuse of discretion standard of review.” (Hillside Memorial Park

& Mortuary v. Golden State Water Co. (2011) 205 Cal.App.4th 534, 549; accord, 

Barstow, supra, 23 Cal.4th at p. 1256 [when trial court “exercise[s] its equitable powers 

in approving the proposed physical solution ..., [court] properly review[s] the judgment 

under the abuse of discretion standard of review”].)

The familiar test for abuse of discretion is “whether the trial court exceeded the 

bounds of reason. When two or more inferences can reasonably be deduced from the 

facts, the reviewing court has no authority to substitute its decision for that of the trial 

court.” (Shamblin v. Brattain (1988) 44 Cal.3d 474, 478–479.) The court’s discretion as 

to equitable remedies, while not unlimited, should be granted deference when the record 

reflects the trial court has considered “the material facts affecting the equities between 

the parties.” (Dickson, Carlson & Campillo v. Pole (2000) 83 Cal.App.4th 436, 447.) 

“‘The burden is on the party complaining to establish an abuse of discretion, and unless a 

clear case of abuse is shown and unless there has been a miscarriage of justice a 

reviewing court will not substitute its opinion and thereby divest the trial court of its 

discretionary power.’” (Denham v. Superior Court (1970) 2 Cal.3d 557, 566.)

Tapia appears to argue we should accord no deference to our review of the court’s 

adopted Physical Solution and judgment because it was premised on stipulations among 

various parties, and stipulated judgments present questions of law subject to de novo 

review. (Crosby v. HLC Properties, Ltd. (2014) 223 Cal.App.4th 597, 602–604; In re 

Marriage of Smith (2007) 148 Cal.App.4th 1115, 1120.) We reject that argument 

because the 2015 judgment, while certainly based on a “stipulation and physical solution 

presented as the [Proposed] Judgment and Physical Solution,” was entered only after 
24.

contested proceedings were held—at which evidence was introduced and challenges were 

considered—and after the court made extensive factual findings and concluded it would 

“adopt [the proposed Physical Solution] as the Court’s own physical solution.” 

Accordingly, we will apply the ordinary abuse of discretion standard to our review of the 

judgment entered as the trial court’s “own physical solution.”

Some of Tapia’s claims appear to rest on express or implied challenges to the 

factual determinations underpinning the judgment and Physical Solution. As to those 

challenges, our review is constrained by the substantial evidence standard of review. 

(Santa Maria, supra, 211 Cal.App.4th at p. 286, citing Reichardt v. Hoffman (1997) 52 

Cal.App.4th 754, 766–767 [“Where appellants challenge the sufficiency of the evidence 

we defer to the trial court”].)

“When a trial court’s factual determination is attacked on the ground that 

there is no substantial evidence to sustain it, the power of an appellate court 

begins and ends with the determination as to whether, on the entire record, 

there is substantial evidence, contradicted or uncontradicted, which will 

support the determination, and when two or more inferences can reasonably 

be deduced from the facts, a reviewing court is without power to substitute 

its deductions for those of the trial court. If such substantial evidence be 

found, it is of no consequence that the trial court believing other evidence, 

or drawing other reasonable inferences, might have reached a contrary 

conclusion.” (Bowers v. Bernards (1984) 150 Cal.App.3d 870, 873–874.)

VI

ANALYSIS

A. The Physical Solution’s Allocation of the NSY Does Not Violate 

California’s Water Priorities

Tapia contends the Physical Solution violates California’s established water rights 

priorities to water in a groundwater basin because the allocation of the available NSY5

offended two principles: (1) it allocated production rights to the PWS despite the PWS 

holding a lower priority than Tapia and (2) it allocated production rights in the NSY to 

5The NSY was 82,300 afy for the AVAA basin as a whole, but after deducting the United 

States’ allotted federal reserved rights, the remaining available NSY was 74,700 afy.
25.

other overlying landowners while depriving Tapia of any equivalent production right in 

disregard of Tapia’s correlative rights with other overliers.

1. The Allocations to the PWS Accords with California Law

Tapia correctly notes overlying landowners have rights to a basin’s groundwater 

that are “superior to that of other persons who lack legal priority” (Barstow, supra, 23 

Cal.4th at p. 1240), and that such overlying rights have priority over appropriators when 

there is no surplus available for an appropriator to draw upon. (See generally Corona 

Foothill Lemon Co. v. Lillibridge (1937) 8 Cal.2d 522, 530–531.) However, allocating 

part of the NSY to the PWS does not violate this precept of California’s structure for 

prioritizing water rights: to the extent the PWS’s uses of the groundwater had ripened 

into a prescriptive interest in the available groundwater, the PWS’s water use was 

transformed from an appropriative use into rights entitled to equivalent priority with the 

rights of overliers.6 (Santa Maria, supra, 211 Cal.App.4th at p. 297 [acquisition of a 

prescriptive right in groundwater “rearranges water rights priorities among water users, 

elevating the right of the one acquiring it above that of an appropriator to a right 

equivalent in priority to that of a landowner”].) Accordingly, we reject Tapia’s claim that 

allocating production rights to the PWS offends California’s structure for prioritizing 

water rights. (See, e.g., San Fernando, supra, 14 Cal.3d at p. 293 [where prescription 

established, party has “a prescriptive right against the water rights concurrently held by a 

6This aspect of Tapia’s argument appears predicated on the claim that the PWS hold only 

appropriative groundwater rights, and in cases of overdraft, Tapia’s overlying rights supersede 

appropriative claims to groundwater. While cases such as Corona Foothill Lemon Co. v. 

Lillibridge, supra, 8 Cal.2d 522 support the general proposition that overlying rights supersede 

appropriative rights (id. at pp. 530–531), Tapia ignores that the court found the PWS had 

perfected certain prescriptive rights, thereby elevating the PWS’s rights to equal priority with 

overlying rights. Because Tapia makes no claim on appeal that the evidence is insufficient to 

support the court’s finding that the PWS had perfected their prescriptive rights as against Tapia, 

Tapia has waived any claim that the court erred in finding the PWS had obtained prescriptive 

rights. (Badie v. Bank of America (1998) 67 Cal.App.4th 779, 784–785.) Accordingly, Tapia’s 

legal argument falters on its false predicate—the Physical Solution did not allocate production 

rights to holders of appropriative rights, but instead allocated production rights to holders of 

prescriptive rights.
26.

private defendant [and] [t]he effect of the prescriptive right would be to give to the party 

acquiring it and take away from the private defendant against whom it was acquired 

either (1) enough water to make the ratio of the prescriptive right to the remaining rights 

of the private defendant as favorable to the former in time of subsequent shortage as it 

was throughout the prescriptive period [citation] or (2) the amount of the prescriptive 

taking, whichever is less”]; Santa Maria, supra, at p. 297.)

2. The Allocations to Correlative Rights Holders Accords with 

California Law

Tapia alternatively asserts the Physical Solution violates California law regarding 

water rights priorities because it allocates the remaining NSY to overlying owners who 

are currently pumping while denying him the correlative share to which he was entitled 

by virtue of owning overlying land.7 Tapia argues this allocation violates correlative 

rights principles, contending these principles confer on Tapia the right to be treated 

equally with all fellow correlative rights holders based solely on his ownership of land, 

regardless of whether Tapia demonstrated he was currently pumping for reasonable and 

beneficial uses for his overlying lands.

Tapia correctly notes that, under California law, protection of an overlier’s rights 

include protection for prospective uses as against the claims of lower priority users 

(Tulare Dist. v. Lindsay-Strathmore Dist. (1935) 3 Cal.2d 489, 525 (Tulare); Hillside

Memorial Park & Mortuary v. Golden State Water Co., supra, 205 Cal.App.4th at p. 

539), and that overliers have a shared or common (correlative) right among each other to 

extract groundwater from the aquifer for the reasonable and beneficial use of their 

property (see Katz v. Walkinshaw, supra, 141 Cal. at p. 136). While overliers have equal 

7Tapia also appears to assert the judgment and Physical Solution improperly deprived 

him of his allocation because it rested on the erroneous disregard of his proof of the extent of his 

pumping for reasonable and beneficial uses. However, as we conclude below, this aspect of 

Tapia’s challenge fails because there was substantial evidence upon which the court could have 

found Tapia failed to show the extent of his pumping for reasonable and beneficial uses, and 

hence failed to show a basis for an allocation of production rights.
27.

priority, such “equal right, in cases where the supply is insufficient for all, [is] to be 

settled by giving to each a fair and just proportion.” (Ibid.) Thus, where (as here) the 

native supply is insufficient to meet the needs of all overliers, each overlier can be 

“limited to his proportionate fair share of the total amount available based upon his 

reasonable need.” (Tehachapi-Cummings, supra, 49 Cal.App.3d at p. 1001.)

The case law, therefore, appears only to require that, as among correlative rights

holders, the division of an inadequate supply is tested by whether such allocation is 

equitable. (Barstow, supra, 23 Cal.4th at p. 1249 [a trial court “within limits, ... may use 

its equitable powers to implement a physical solution”]; cf. Tehachapi-Cummings, supra, 

49 Cal.App.3d at p. 1001 [correlative rights “means that each has a common right to take 

all that he can beneficially use on his land if the quantity is sufficient; if the quantity is 

insufficient, each is limited to his proportionate fair share of the total amount available 

based upon his reasonable need” (italics added)].) Thus, when crafting a physical 

solution for an overdrafted groundwater basin where a court must allocate a water supply 

that is insufficient to meet the reasonable needs of all who hold correlative rights, a court 

may employ equitable apportionment principles to allocate the available supply among 

competing claimants with equivalent priorities, as long as that physical solution does not 

“wholly disregard[] the priorities of existing water rights in favor of equitable 

apportionment ... [and] adequately consider[s] and reflect[s] the priority of water rights 

in the basin.” (Barstow, supra, 23 Cal.4th at pp. 1247–1248; accord, City of Pasadena v. 

City of Alhambra, supra, 33 Cal.2d at p. 926 [overlying rights are held in common and 

each overlier “may use only his reasonable share when water is insufficient to meet the 

needs of all” (italics added)].)

We conclude that, when apportioning water in an overdrafted basin among 

correlative rights holders, a court may employ equitable apportionment principles to the 

extent necessary to reach a practical apportionment of the available water among parties 

holding equivalent priorities. (Cf. San Fernando, supra, 14 Cal.3d at p. 265 [allocating 
28.

water based on prescriptive rights “does not necessarily result in the most equitable 

apportionment of water according to need. A true equitable apportionment would take 

into account many more factors”].) Equitable apportionment should factor in the various 

legal priorities accorded to the competing users, but “‘if an allocation ... is to be just and 

equitable, strict adherence to the priority rule may not be possible. ... Apportionment 

calls for the exercise of an informed judgment on a consideration of many factors.

Priority of appropriation is the guiding principle. But physical and climatic conditions, 

the consumptive use of water in the several sections of the river, the character and rate of 

return flows, the extent of established uses, the availability of storage water, the practical 

effect of wasteful uses on downstream areas, the damage to upstream areas as compared 

to the benefits to downstream areas if a limitation is imposed on the former—these are all 

relevant factors. They are merely illustrative, not an exhaustive catalogue. They indicate 

the nature of the problem of apportionment and the delicate adjustment of interests which 

must be made.’” (Id. at pp. 265–266, fn. 61, quoting Nebraska v. Wyoming (1945) 325 

U.S. 589, 618.)

The Barstow court, although concluding a physical solution based on equitable 

apportionment must adequately account for the water rights priorities of those impacted 

by the apportionment, nevertheless agreed that “within limits, a trial court may use its 

equitable powers to implement a physical solution” (Barstow, supra, 23 Cal.4th at p. 

1249), and “may impose a physical solution to achieve a practical allocation of water to 

competing interests.” (Id. at p. 1250.) Indeed, Barstow appears to uphold (at least by 

negative implication) the use of equitable apportionment principles when considering 

how to apportion water among correlative rights holders. (See Barstow, at p. 1248 

[“Case law ... does not support applying an equitable apportionment to water use claims 

unless all claimants have correlative rights” (italics added)].)

Tapia appears to assert the Physical Solution’s equitable apportionment of the 

remaining NSY among overliers wholly disregarded his correlative rights, in violation of 
29.

Barstow’s admonition, because it extinguishes all future access by Tapia to any part of 

the NSY for his future use in contravention of California law. Certainly, California seeks 

to protect both actual uses and prospective reasonable beneficial uses by overliers. (See 

generally Hillside Memorial Park & Mortuary v. Golden State Water Co., supra, 205 

Cal.App.4th at p. 539.) However, the protection of the interests of correlative rights 

holders who are actually using all available water for reasonable and beneficial purposes 

may (under appropriate circumstances) permit a court to craft a physical solution that

acknowledges the rights held by overliers such as Tapia, but subordinates any future use 

by Tapia to his fellow correlative rights holders who (unlike Tapia) demonstrated they 

presently use the available supply for reasonable and beneficial purposes.

In In re Waters of Long Valley Creek Stream System (1979) 25 Cal.3d 339 (Long 

Valley), our Supreme Court addressed a comprehensive water rights adjudication in the 

same circumstances as are present here: a water source that was being completely used 

but had substantial unexercised claims upon it that were held by correlative rights 

holders. The Long Valley court held that prospective future uses of significant 

unexercised correlative water rights may be conditioned and subordinated to protect 

existing uses and reliance interests as part of a comprehensive water rights adjudication 

that allocated a limited water supply among competing claimants. (Id. at pp. 358–359.) 

In Long Valley, the court evaluated a riparian owner’s challenge to the allocation by the 

State Water Resources Control Board, which allocated water to him for his ongoing 

irrigation of his riparian land but allocated no water for his prospective future use on his 

remaining undeveloped land. (Id. at p. 346.) The owner argued that foreclosing his 

future access to the water was improper because Tulare, supra, 3 Cal.2d 489, barred 

extinguishment of his prospective riparian right merely to ensure water would remain 

available for other existing interests competing for the same inadequate supply. (Long 
30.

Valley, supra, at pp. 353-354.) Rejecting that argument in part,

8

the Long Valley court 

held that article X, section 2 of the California Constitution authorized the board to 

determine that an undemonstrated or speculative riparian claim “loses its priority with 

respect to all rights currently being exercised.” (Long Valley, at pp. 358–359.) The court 

further held the board could “also determine that the future riparian right shall have a 

lower priority than any uses of water it authorizes before the riparian in fact attempts to 

exercise his right.” (Ibid.) “In other words, while [state law does not] authoriz[e] the 

Board to extinguish altogether a future riparian right, the Board may make determinations 

as to the scope, nature and priority of the right that it deems reasonably necessary to the 

promotion of the state’s interest in fostering the most reasonable and beneficial use of its 

scarce water resources.” (Id. at p. 359.)

Long Valley makes clear that, when there is a comprehensive adjudication in 

which a court is called upon to divide and allocate a limited supply among competing 

equal priority users whose demonstrated cumulative demands exceed the capacity of that 

resource, California law (although precluding any solution purporting to entirely 

extinguish correlative rights to future uses) permits the court to determine “the scope, 

nature and priority of the right” as the court may “deem[] reasonably necessary to the 

promotion of the state’s interest in fostering the most reasonable and beneficial use of its 

scarce water resources.” (Long Valley, supra, 25 Cal.3d at p. 359.) The structure of the 

8The board’s order in Long Valley purported to entirely “extinguish” any unexercised 

riparian rights appurtenant to the owner’s remaining lands (Long Valley, supra, 25 Cal.3d at p. 

346), which Long Valley observed was a “more difficult question.” (Id. at p. 357.) The Long 

Valley court ultimately held there was no “persuasive argument for concluding that complete 

extinction of such rights is necessary to the promotion of the reasonable and beneficial use of a 

stream system, nor ... that the reasonable and beneficial use of the waters in the Long Valley 

Creek cannot be equally well promoted by placing limitations on [the owner’s] future riparian 

right other than complete extinction ... such as the quantification of the future right, or assigning 

to it a lower priority than all present and future actual reasonable beneficial uses made prior to 

the riparian’s attempted use [in the future].” (Id. at p. 357, italics added.) Thus, while Long 

Valley bars an adjudication that entirely extinguishes future overlying rights, it does not bar an 

adjudication that preserves those rights but subordinates them to present and future actual 

reasonable beneficial uses that arose prior to a dormant right holder’s attempt to use the supply.
31.

judgment and Physical Solution here comports with that approach: the court found that 

Tapia had not shown the extent or reasonableness of his claimed beneficial uses, and 

therefore had not demonstrated any statutory or equitable basis for an allocation of the 

NSY under the Physical Solution, and that Tapia would be “subject to the provisions of 

the Physical Solution.” The judgment thus recognized Tapia’s overlying future rights but 

required any future exercise of that preserved right be exercised “subject to the provisions 

of the Physical Solution.” The Physical Solution, by allocating the remaining available 

NSY to holders of priority rights who demonstrated actual and reasonable beneficial uses 

of their correlative interests, effectively subordinated Tapia’s future exercise of his 

correlative rights to the present exercise by correlative rights holders who demonstrated 

their existing reasonable domestic and nondomestic uses. We conclude the Physical 

Solution, by preserving but subordinating Tapia’s access to the NSY, comports with 

California law as construed and applied in Long Valley.

B. The Physical Solution’s Allocation of the NSY Does Not Violate 

California’s Principles Promoting the Reasonable and Beneficial Use of 

Water

Tapia argues the Physical Solution violates a cardinal constitutional requirement—

that water be put to reasonable and beneficial uses to the fullest extent possible and its 

waste be prevented—because various elements of the Physical Solution or judgment are 

incompatible with that requirement.

An overarching consideration for any water rights adjudication is that the 

judgment should promote California’s policy that available water be put to the maximum 

beneficial use possible, with waste or unreasonable use prevented, under the 

circumstances presented. (Barstow, supra, 23 Cal.4th at pp. 1241–1242.) Barstow

explained the requirement of this constitutional imperative:

“‘[T]he trial court ... determine[s] whether [overlying rights holding] 

owners, considering all the needs of those in the particular water field, are 

putting the waters to any reasonable beneficial uses, giving consideration to 

all factors involved, including reasonable methods of use and reasonable 
32.

methods of diversion....’ (Tulare[, supra, 3 Cal.2d at pp.] 524–525 ....) 

We have reiterated these principles in subsequent cases, observing that 

although ‘what is a reasonable use of water depends on the circumstances 

of each case, such an inquiry cannot be resolved in vacuo isolated from 

statewide considerations of transcendent importance. Paramount among 

these we see the ever increasing need for the conservation of water in this 

state, an inescapable reality of life quite apart from its express recognition 

in the 1928 amendment.’ (Joslin v. Marin Mun. Water Dist. (1967) 67

Cal.2d 132, 140, fn. omitted.)” (Barstow, at p. 1242.)

Tapia contends the Physical Solution violates these principles in several ways, 

including that it allocates the available NSY on a permanent basis, and it was not based 

on an adequate evaluation of the reasonableness of each individual’s existing use.9

Tapia first asserts allocating the NSY on a “permanent” basis could violate the 

reasonable and beneficial use requirement at some point in the future. Specifically, he 

argues a particular user who received an allocation might change the user’s current use 

from a currently “reasonable” use to a later “unreasonable” use, and there is no 

mechanism within the Physical Solution designed to detect such changed usages or to 

allow for modification of the allocations to prevent such unreasonable uses. Even 

assuming this claim is preserved,

10 the courts have recognized that physical solutions are 

9Tapia’s opening brief also asserts the reasonable and beneficial use mandate was 

violated because the Physical Solution (1) awarded a small water right as an incentive award to 

the Wood Class representative, (2) granted certain of the parties the ability to transfer and/or 

carryover any allocated amount, and (3) deprived Tapia of any share of the NSY based on the 

assumption any future pumping by him would be unreasonable. However, these assertions are 

interposed peremptorily, and are entirely undeveloped (by either citation to the record or by legal 

argument) in Tapia’s opening brief. Because these assertions are unsupported by citations either 

to the record or to pertinent legal authority, we do not further consider them. (Badie v. Bank of 

America, supra, 67 Cal.App.4th at pp. 784–785 [“When an appellant fails to raise a point, or 

asserts it but fails to support it with reasoned argument and citations to authority, we treat the 

point as waived”]; San Diego Navy Broadway Complex Coalition v. California Coastal Com.

(2019) 40 Cal.App.5th 563, 588 [where contentions are unaccompanied by substantive 

arguments or citation to pertinent evidence, courts deem the arguments waived].)

10It is axiomatic that a party who fails to object below forfeits its claim of error (K.C. 

Multimedia. Inc. v. Bank of America Technology & Operations, Inc. (2009) 171 Cal.App.4th 

939, 950), and Tapia has not directed our attention to that part of the record in which there was 

any objection below that the absence of a monitoring and adjustment system rendered the 

Physical Solution incompatible with California’s reasonable and beneficial use requirement, 
33.

designed “to achieve a practical allocation of water to competing interests” (Barstow, 

supra, 23 Cal.4th at p. 1250, italics added; accord, Imperial Irrigation Dist. v. State Wat. 

Resources Control Bd., supra, 225 Cal.App.3d at p. 572), and Tapia’s implied suggestion 

that allocations may not have permanence but must instead be malleable appears 

inconsistent with achieving a “practical” allocation of water among competing interests. 

(Ibid.) Indeed, other courts have implicitly concluded physical solutions may incorporate 

“permanent” allocations.11 (See generally Long Valley, supra, 25 Cal.3d 339; In re 

Water of Hallett Creek Stream System (1988) 44 Cal.3d 448; City of Pasadena v. City of 

Alhambra, supra, 33 Cal.2d 908.) Moreover, Tapia’s suggestion the Physical Solution 

violates the reasonable and beneficial use mandate because the court is powerless to 

modify allocations to prevent subsequent unreasonable uses ignores section 6.5 of the 

Physical Solution. That section specifies the court has reserved “full jurisdiction ... for 

the purpose of enabling the Court, upon a motion of a Party or Parties ... to make such 

further or supplemental order or directions as may be necessary or appropriate to 

interpret, enforce, administer or carry out this Judgment and to provide for such other 

matters as are not contemplated by this Judgment and which might occur in the future, 

and which if not provided for would defeat the purpose of this Judgment.” (Italics 

added.) The declared purposes of the judgment and Physical Solution are to “further[] ...

the State Constitution mandate and the State water policy” and to “establish[] a legal and 

which permits us to deem the argument forfeited. (In re S.C. (2006) 138 Cal.App.4th 396, 406–

407 [“When an appellant’s brief makes no reference to the pages of the record where a point can 

be found, an appellate court need not search through the record in an effort to discover the point 

purportedly made. [Citations.] We can simply deem the contention to lack foundation and, thus, 

to be forfeited”].) While the absence of timely objection below would ordinarily entirely bar 

Tapia from raising this claim for the first time on appeal (Save Our Heritage Organisation v. 

City of San Diego (2015) 237 Cal.App.4th 163, 181), we nevertheless evaluate this claim.

11Tapia’s contrary suggestion—that allocations must be subject to revisitation and 

relitigation at unspecified periodic intervals—is unsupported by any relevant legal authority. 

Although Tapia cites Joslin v. Marin Mun. Water Dist., supra, 67 Cal.2d at page 143 for the 

proposition that “‘reasonable and beneficial use’ determinations must constantly be reevaluated,” 

Joslin did not address the requirements of a valid physical solution, nor does it contain language 

suggesting a court must constantly revisit water rights adjudications.
34.

practical means for making the maximum reasonable and beneficial use of the waters of 

the Basin ... in order to meet the reasonable and beneficial use requirements of water 

users in the Basin” (Physical Solution § 7.1), and to “provide flexibility and adaptability 

to allow the Court to use existing and future technological, social, institutional, and 

economic options in order to maximize reasonable and beneficial water use in the Basin”

(Physical Solution § 7.2). Because these declared purposes include “maximiz[ing] 

reasonable and beneficial water use,” and the court retained jurisdiction to address 

matters that “might occur in the future and which if not provided for would defeat the 

purpose of this Judgment” (italics added), there is adequate protection against potential 

future uses that might transgress the reasonable and beneficial use mandates.12

Tapia also asserts the court adopted the Physical Solution without an “adequate” 

examination of whether the allotted production rights were being devoted to “reasonable 

and beneficial” purposes. (Tulare, supra, 3 Cal.2d at p. 535.) We disagree. The court 

heard extensive evidence from two experts, Robert Beeby and Robert Wagner, who 

opined the parties who were presently using water (and who received allocated 

production rights) were reasonably using the amounts of water they extracted and were 

devoting it to beneficial purposes.13 Tapia does not appear to assert the inquiry was 

12For these reasons, we also reject Tapia’s argument that Santa Maria, supra, 211 

Cal.App.4th 266 undercuts the validity of the Physical Solution adopted here. Santa Maria

stated: “‘[I]f a physical solution be ascertainable, the court has the power to make and should 

make reasonable regulations for the use of the water by the respective parties, provided they be 

adequate to protect the one having the paramount right in the substantial enjoyment thereof and 

to prevent its ultimate destruction, and in this connection the court has the power to and should 

reserve unto itself the right to change and modify its orders and decree as occasion may demand, 

either on its own motion or on motion of any party.’ ([Peabody v. City of Vallejo, supra, 2 

Cal.2d] at pp. 383–384.)” (Id. at p. 288, italics added.) That is precisely the ability reserved by 

the Physical Solution as described above.

13Beeby’s testimony was supported by detailed spreadsheets, which used the data drawn 

from the evidence submitted during the Phase 4 trial, identifying numerous users’ pre-rampdown 

average yearly pumping, the acres to which such water was applied, and identifying the 

beneficial uses to which such water was devoted. This data provided the basis for his conclusion 

that, with limited exceptions, the amounts drawn were being reasonably used for beneficial 
35.

inadequate as to other landowners, but instead asserts the inquiry was inadequate as to 

Tapia because he also presented evidence of the amounts he used and the purposes for 

such use that the trial court erroneously rejected. As we conclude below, we do not 

review this aspect of Tapia’s claim de novo but must instead affirm the finding if there is 

substantial evidence to support the ruling as to Tapia. Because we conclude the court’s 

inquiry into the reasonable and beneficial uses of the water by those receiving production 

rights was adequate, and the evidence supports the trial court’s findings thereon, we 

reject Tapia’s argument that the court inadequately assessed whether the Physical 

Solution satisfied the reasonable and beneficial use requirement.

C. Substantial Evidence Supports the Judgment as to Tapia

Tapia argues the trial court erred in denying him production rights to “continue to 

use water at their current levels” (capitalization omitted) because he established—through 

his testimony as well as two declarations allegedly admitted at trial—his baseline 

groundwater use and the reasonable and beneficial use for that water.14 Tapia, although 

recognizing a trial court may fashion a remedy through a Physical Solution to preserve a 

water basin, argues it may “neither change priorities among the water rights holder nor 

eliminate vested rights in applying the solution without first considering them in relation 

to the reasonable use doctrine” (Barstow, supra, 23 Cal.4th at p. 1250), and asserts the 

trial court’s Physical Solution violated Barstow’s equitable apportionment mandate by 

eliminating Tapia’s vested rights without considering the evidence he presented at trial.

purposes. Wagner also reviewed the materials documenting the amounts of water historically 

used by the various parties and the types of uses to which they devoted that water, and opined the 

parties receiving production rights under the Physical Solution had historically applied their 

water to beneficial uses in amounts that were appropriate for such beneficial purposes.

14The evidence established, and on appeal Tapia does not claim to the contrary, that the 

PWS had obtained prescriptive rights as against Tapia. Instead, Tapia also appears to assert on 

appeal the Physical Solution unreasonably burdens Tapia, in violation of Barstow, supra, 23 

Cal.4th 1224, by stripping him of all economic benefits of the land. While the Physical Solution 

certainly limits Tapia’s use of free groundwater, Tapia apparently farmed the property using 

imported water through at least 2009, which belies his appellate claim that the limits imposed on 

Tapia deprived him of any economically viable use of his farm.
36.

The record is clear that the trial court carefully listened to Tapia’s evidence15

(asserting he had used an average of 534.5 afy during the “baseline” period for use on his 

overlying property), but ultimately rejected Tapia’s evidence as lacking credibility. Our 

role on appeal is not to determine whether Tapia presented sufficient evidence that could

have supported a contrary finding, but whether there is substantial evidence to support the 

trial court’s finding that Tapia “failed to prove their groundwater use.” “As the trier of 

fact, the trial court is the sole judge of the credibility and weight of the evidence; we do 

not judge credibility on appeal.” (In re Marriage of Brewster & Clevenger (2020) 45 

Cal.App.5th 481, 500.) Instead, we examine only whether there was substantial evidence 

to support the trial court’s finding that Tapia’s claimed use of 534.5 afy of water lacked 

credibility.16 (See Bowers v. Bernards, supra, 150 Cal.App.3d at pp. 873–874 [“If such 

substantial evidence be found, it is of no consequence that the trial court believing other 

evidence, or drawing other reasonable inferences, might have reached a contrary 

conclusion”].)

Here, Tapia’s claimed use of an average of 534.5 afy to irrigate his farmland for 

the production of sweet corn and pumpkins was rebutted by numerous aspects of the 

evidence. Tapia estimated his water use based on his total electrical bills for the baseline 

period, but he admitted (and the evidence showed) that the electrical bills upon which this 

extrapolation was based measured electrical use for other applications (not merely the 

15The record shows the trial court interposed an occasional question to Tapia to help 

clarify his testimony, and also asked its own additional questions before Tapia finished his 

testimony.

16We note Tapia’s opening brief cites only to his own evidence and does not mention any 

evidence or testimony contradicting his testimony. “An appellant challenging the sufficiency of 

the evidence to support the judgment must cite the evidence in the record supporting the 

judgment and explain why such evidence is insufficient as a matter of law.” (Rayii v. Gatica

(2013) 218 Cal.App.4th 1402, 1408.) Failure to discuss contrary evidence waives any argument 

the judgment is not supported by substantial evidence. (Ibid.; Mendoza v. City of West Covina

(2012) 206 Cal.App.4th 702, 713–714 [“completely one-sided presentation of the facts” waives 

the challenge to sufficiency of evidence].) Accordingly, while we could deem this claim waived, 

we have elected to examine this claim.
37.

well), which rendered unreliable Tapia’s sole metric for estimating water use during 2011 

and 2012. Moreover, even assuming some portion of the electricity was measuring 

pumped water, Tapia admitted the well had a split in the main line that ultimately left his 

property and irrigated land he did not own, and he had “no idea” what part of the water 

pumped was used on land owned by others. There was also satellite imagery showing 

that (in 2012) nearly 75 percent of Tapia’s farm was “fallowed” so that his claimed water 

use was far in excess of the level of water necessary to grow pumpkins and corn on the 

land actually under cultivation. Beeby also extensively testified that, based on his 

expertise as to the amount of water needed to cultivate pumpkins and corn, Tapia’s 

claimed history of water consumption for farming those crops on the amount of land 

actually farmed was “far [in] excess of anything that did make sense.”

On this record, there was ample basis for the trier of fact to conclude Tapia’s 

claimed water use was not credible. Accordingly, we conclude Tapia has not 

demonstrated the evidence was insufficient to support the judgment as to Tapia.

We conclude substantial evidence supports the judgment as to Tapia, and the 

Physical Solution is consistent with California law governing water priorities and the 

constitutional reasonable and beneficial use requirement.

DISPOSITION

The judgment is affirmed as to Tapia. Each party is responsible for its costs on 

appeal.

PEÑA, Acting P.J.

WE CONCUR:

SMITH, J.

SNAUFFER, J.
Filed 4/14/21

CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIFTH APPELLATE DISTRICT

ANTELOPE VALLEY GROUNDWATER CASES*

F082492

LOS ANGELES COUNTY WATERWORKS 

DISTRICT NO. 40 et al.,

Cross-complainants and Respondents,

v.

CHARLES TAPIA, Individually and as Trustee, 

etc., et al.,

Cross-defendants and Appellants;

ANTELOPE VALLEY–EAST KERN WATER 

AGENCY,

Cross-defendant, Cross-complainant and 

Respondent;

(JCCP No. 4408)

*Los Angeles County Waterworks District No. 40 v. Diamond Farming Co. (Super. Ct. 

Los Angeles County, No. BC325201); Los Angeles County Waterworks District No. 40 v. 

Diamond Farming Co. (Super. Ct. Kern County, No. S-1500-CV254348); Wm. Bolthouse 

Farms, Inc. v. City of Lancaster (Super. Ct. Riverside County, No. RIC353840); Diamond 

Farming Co. v. City of Lancaster (Super. Ct. Riverside County, No. RIC344436); Diamond 

Farming Co. v. Palmdale Water Dist. (Super. Ct. Riverside County, No. RIC344668); Willis v. 

Los Angeles County Waterworks District No. 40 (Super. Ct. Los Angeles County, 

No. BC364553); Wood v. Los Angeles County Waterworks District No. 40 (Super. Ct. Los 

Angeles County, No. BC391869).
2.

U.S. BORAX INC. et al.,

Cross-defendants and Respondents.

As the nonpublished opinion filed on March 16, 2021, in the above matter meets 

the standards for publication specified in the California Rules of Court, rule 8.1105(c), it 

is ordered that the opinion be certified for publication in the Official Reports.

PEÑA, Acting P.J.

WE CONCUR:

SMITH, J.

SNAUFFER, J.