                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


UNITED STATES OF AMERICA,             No. 15-16316
                        Plaintiff,
                                         D.C. No.
WALKER RIVER PAIUTE TRIBE,            3:73-cv-00125-
              Intervenor-Plaintiff,     RCJ-WGC

NATIONAL FISH AND WILDLIFE
FOUNDATION,
                      Petitioner,

MINERAL COUNTY,
             Intervenor-Plaintiff,

               and

NEVADA STATE ENGINEER,
           Respondent-Appellant,

                v.

UNITED STATES BOARD OF WATER
COMMISSIONERS,
             Participant-Appellee,

BACKTRACK, LLC; BALE COUNTER,
INC.; GARY M. BERRINGTON;
BERRINGTON CUSTOM HAY
HAULING & TRANS., INC.; DAMIAN,
LTD.; PETER A. FENILI; GDA
2 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

DEGREE, INC.; GARY G. GARMS;
GARY J. GARMS; KARI D. GARMS;
TONI GARMS; GARMSLAND LIMITED,
LLC; HIGH SIERRA GARLIC;
JACKAROO, LLC; SETTELMEYER-
ROSSE RANCH MANAGEMENT, LLC;
SIX-N-RANCH, INC.; STRAGGLER,
LLC,
               Objectors-Appellees,

               and

NEVADA DEPARTMENT OF WILDLIFE;
CALIFORNIA STATE WATER
RESOURCES CONTROL BOARD;
MONO COUNTY, CALIFORNIA; LYON
COUNTY, NEVADA,
                   Respondents,

WALKER LAKE WORKING GROUP;
WALKER RIVER IRRIGATION
DISTRICT,
                     Defendants.
  NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 3

UNITED STATES OF AMERICA,             No. 15-16317
                        Plaintiff,
                                         D.C. No.
WALKER RIVER PAIUTE TRIBE,            3:73-cv-00125-
              Intervenor-Plaintiff,     RCJ-WGC

NATIONAL FISH AND WILDLIFE
FOUNDATION,
                      Petitioner,

MINERAL COUNTY,
             Intervenor-Plaintiff,

               and

NEVADA DEPARTMENT OF WILDLIFE,
           Respondent-Appellant,

                v.

UNITED STATES BOARD OF WATER
COMMISSIONERS,
             Participant-Appellee,

BACKTRACK, LLC; BALE COUNTER,
INC.; GARY M. BERRINGTON;
BERRINGTON CUSTOM HAY
HAULING & TRANS., INC.; DAMIAN,
LTD.; PETER A. FENILI; GDA
DEGREE, INC.; GARY G. GARMS;
GARY J. GARMS; KARI D. GARMS;
TONI GARMS; GARMSLAND LIMITED,
LLC; HIGH SIERRA GARLIC;
4 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

JACKAROO, LLC; SETTELMEYER-
ROSSE RANCH MANAGEMENT, LLC;
SIX-N-RANCH, INC.; STRAGGLER,
LLC,
              Objectors-Appellees,

               and

NEVADA STATE ENGINEER;
CALIFORNIA STATE WATER
RESOURCES CONTROL BOARD;
MONO COUNTY, CALIFORNIA; LYON
COUNTY, NEVADA,
                   Respondents,

WALKER LAKE WORKING GROUP;
WALKER RIVER IRRIGATION
DISTRICT,
                     Defendants.
  NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 5

UNITED STATES OF AMERICA,             No. 15-16319
                        Plaintiff,

WALKER RIVER PAIUTE TRIBE,               D.C. No.
              Intervenor-Plaintiff,   3:73-cv-00125-
                                        RCJ-WGC
MINERAL COUNTY,
             Intervenor-Plaintiff,

               and

NATIONAL FISH AND WILDLIFE
FOUNDATION,
              Petitioner-Appellant,

                v.

UNITED STATES BOARD OF WATER
COMMISSIONERS,
             Participant-Appellee,

BACKTRACK, LLC; BALE COUNTER,
INC.; GARY M. BERRINGTON;
BERRINGTON CUSTOM HAY
HAULING & TRANS., INC.; DAMIAN,
LTD.; PETER A. FENILI; GDA
DEGREE, INC.; GARY G. GARMS;
GARY J. GARMS; KARI D. GARMS;
TONI GARMS; GARMSLAND LIMITED,
LLC; HIGH SIERRA GARLIC;
JACKAROO, LLC; SETTELMEYER-
ROSSE RANCH MANAGEMENT, LLC;
SIX-N-RANCH, INC.; STRAGGLER,
6 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

LLC,
              Objectors-Appellees,

              and

NEVADA STATE ENGINEER; NEVADA
DEPARTMENT OF WILDLIFE;
CALIFORNIA STATE WATER
RESOURCES CONTROL BOARD;
MONO COUNTY, CALIFORNIA; LYON
COUNTY, NEVADA,
                   Respondents,

WALKER LAKE WORKING GROUP;
WALKER RIVER IRRIGATION
DISTRICT,
                     Defendants.
  NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 7

UNITED STATES OF AMERICA,             No. 15-16321
                        Plaintiff,

WALKER RIVER PAIUTE TRIBE,               D.C. No.
              Intervenor-Plaintiff,   3:73-cv-00125-
                                        RCJ-WGC
NATIONAL FISH AND WILDLIFE
FOUNDATION,
                      Petitioner,

MINERAL COUNTY,
             Intervenor-Plaintiff,

               and

WALKER RIVER IRRIGATION
DISTRICT,
            Defendant-Appellant,

                v.

UNITED STATES BOARD OF WATER
COMMISSIONERS,
             Participant-Appellee,

BACKTRACK, LLC; BALE COUNTER,
INC.; GARY M. BERRINGTON;
BERRINGTON CUSTOM HAY
HAULING & TRANS., INC.; DAMIAN,
LTD.; PETER A. FENILI; GDA
DEGREE, INC.; GARY G. GARMS;
GARY J. GARMS; KARI D. GARMS;
TONI GARMS; GARMSLAND LIMITED,
8 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

LLC; HIGH SIERRA GARLIC;
JACKAROO, LLC; SETTELMEYER-
ROSSE RANCH MANAGEMENT, LLC;
SIX-N-RANCH, INC.; STRAGGLER,
LLC,
              Objectors-Appellees,

               and

NEVADA STATE ENGINEER; NEVADA
DEPARTMENT OF WILDLIFE; MONO
COUNTY, CALIFORNIA; LYON
COUNTY, NEVADA,
                    Respondents,

WALKER LAKE WORKING GROUP,
                    Defendant.
  NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 9

UNITED STATES OF AMERICA,              No. 15-16323
                        Plaintiff,

WALKER RIVER PAIUTE TRIBE,                D.C. No.
              Intervenor-Plaintiff,    3:73-cv-00125-
                                         RCJ-WGC
NATIONAL FISH AND WILDLIFE
FOUNDATION,
                      Petitioner,

                and

MINERAL COUNTY,
     Intervenor-Plaintiff-Appellant,

WALKER LAKE WORKING GROUP,
            Defendant-Appellant,

                 v.

UNITED STATES BOARD OF WATER
COMMISSIONERS,
             Participant-Appellee,

BACKTRACK, LLC; BALE COUNTER,
INC.; GARY M. BERRINGTON;
BERRINGTON CUSTOM HAY
HAULING & TRANS., INC.; DAMIAN,
LTD.; PETER A. FENILI; GDA
DEGREE, INC.; GARY G. GARMS;
GARY J. GARMS; KARI D. GARMS;
TONI GARMS; GARMSLAND LIMITED,
LLC; HIGH SIERRA GARLIC;
10 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

JACKAROO, LLC; SETTELMEYER-
ROSSE RANCH MANAGEMENT, LLC;
SIX-N-RANCH, INC.; STRAGGLER,
LLC,
              Objectors-Appellees,

               and

NEVADA STATE ENGINEER; NEVADA
DEPARTMENT OF WILDLIFE; MONO
COUNTY, CALIFORNIA; LYON
COUNTY, NEVADA,
                    Respondents,

WALKER RIVER IRRIGATION
DISTRICT,
                      Defendant.
  NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 11

UNITED STATES OF AMERICA,             No. 15-16489
                        Plaintiff,
                                         D.C. No.
NATIONAL FISH AND WILDLIFE            3:73-cv-00125-
FOUNDATION,                             RCJ-WGC
                      Petitioner,

MINERAL COUNTY,                         OPINION
             Intervenor-Plaintiff,

               and

WALKER RIVER PAIUTE TRIBE,
    Intervenor-Plaintiff-Appellant,

                v.

UNITED STATES BOARD OF WATER
COMMISSIONERS,
             Participant-Appellee,

BACKTRACK, LLC; BALE COUNTER,
INC.; GARY M. BERRINGTON;
BERRINGTON CUSTOM HAY
HAULING & TRANS., INC.; DAMIAN,
LTD.; PETER A. FENILI; GDA
DEGREE, INC.; GARY G. GARMS;
GARY J. GARMS; KARI D. GARMS;
TONI GARMS; GARMSLAND LIMITED,
LLC; HIGH SIERRA GARLIC;
JACKAROO, LLC; SETTELMEYER-
ROSSE RANCH MANAGEMENT, LLC;
12 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

SIX-N-RANCH, INC.; STRAGGLER,
LLC,
              Objectors-Appellees,

                and

NEVADA DEPARTMENT OF WILDLIFE;
NEVADA STATE ENGINEER;
CALIFORNIA STATE WATER
RESOURCES CONTROL BOARD;
MONO COUNTY, CALIFORNIA; LYON
COUNTY, NEVADA,
                   Respondents,

WALKER LAKE WORKING GROUP;
WALKER RIVER IRRIGATION
DISTRICT; JOSEPH LANDOLT;
BEVERLY LANDOLT,
                      Defendants.

      Appeal from the United States District Court
               for the District of Nevada
      Robert Clive Jones, District Judge, Presiding

        Argued and Submitted August 30, 2017
                Pasadena, California

                  Filed May 22, 2018

    Before: A. Wallace Tashima, Raymond C. Fisher,
            and Jay S. Bybee, Circuit Judges.

                Opinion by Judge Bybee
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 13

                            SUMMARY*


                            Water Rights

    The panel reversed the district court’s judgment and
remanded in an action brought by farmers who alleged injury
to their water rights arising from state agency approval of
modifications to a water rights leasing program in the Walker
River Basin.

    The Nevada district court has maintained in rem
jurisdiction over the waters of Walker River in accordance
with the Walker River Decree of 1936, which governs the
water rights in the Walker River Basin. In 2009, Congress
established the Walker Basin Restoration Program, which
allocated funding to be administered by the National Fish and
Wildlife Foundation to acquire water and water rights for the
purpose of restoring and maintaining Walker Lake, the
terminus of the Walker River. Under the program, the
Foundation leases or purchases flow and storage rights from
willing sellers, and uses those rights to convey water
downstream to feed the Lake.

    The Foundation and the Walker River Irrigation District
both submitted applications seeking modifications to their
decreed water rights. The Foundation requested changes to
the place of use where water was diverted, and changes to the
purpose of use from irrigation to wildlife purposes. The
Nevada State Engineer approved the Foundation’s
application, finding that no party would suffer injury from the

    *
      This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
14 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

changes because the Foundation agreed to limit its in-stream
water use to the historic consumptive use portion of its
decreed water rights, the amount actually used and consumed
by agriculture, and to dedicate to the non-consumptive
portion to mitigate hydrological system loss.

    The California State Water Control Board approved the
separate application of the Irrigation District to temporarily
change its decreed water storage rights, finding that the
farmers who objected to the proposed changes failed to
demonstrate any right to the stored water that would be
injured. The district court rejected the state agency rulings,
refused to grant the change applications, and remanded to the
state agencies after finding that the proposed modifications
would injure the water rights of farmers.

    The panel held that (1) it had jurisdiction over the action
because the district court’s remand order was sufficiently
final, (2) state law applied, (3) it would review the district
court’s decision de novo, and (4) the district court was
required to afford the same level of deference to the state
agencies as the state courts would.

    The panel held that the district court failed to defer to the
findings and conclusions of the state agencies. The panel
considered the record before the Nevada State Engineer, and
concluded that the Engineer properly found that a transfer to
the Foundation limited to the consumption portion would
avoid conflict and injury to other existing water rights. The
panel held that the findings were supported by substantial
evidence and that the Engineer applied the correct legal rule.
The panel held that to the extent the district court made its
own findings of fact, those findings were clearly erroneous.
The panel further held that the California State Water Control
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 15

Board’s finding that the changes proposed by the Irrigation
District “would not injure any legal use of the water” was
consistent with the Walker River Decree of 1936 and in
accord with California law.

    The panel held that Walker Lake is part of the Walker
River Basin. Consequently, the panel held that dedicating
water from the Walker River to Walker Lake did not violate
the Decree’s prohibition on delivering water outside of the
basin of the Walker River. The panel reversed the district
court’s judgment, vacated the district court’s opinion and
remanded for approval of the change applications.


                       COUNSEL

Don Springmeyer (argued) and Christopher Mixson, Wolf
Rifkin Shapiro Schulman & Rabkin LLP, Las Vegas, Nevada;
Jamie Morin, Mentor Law Group PLLC, Seattle, Washington;
for Petitioner-Appellant National Fish and Wildlife
Foundation.

Micheline Noel Nadeau Fairbank (argued) and Bryan L.
Stockton, Senior Deputy Attorneys General; Adam Paul
Laxalt, Attorney General; Office of the Attorney General,
Carson City, Nevada; for Respondent-Appellant State of
Nevada.

Gordon DePaoli (argued) and Dale E. Ferguson, Woodburn
and Wedge, Reno, Nevada, for Defendant-Appellant Walker
River Irrigation District.

Simeon Herskovits (argued), Advocates for Community &
Environment, El Prado, New Mexico; Sean A. Rowe, Mineral
16 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

County District Attorney, Hawthorne, Nevada; for Plaintiff-
Intervenor-Plaintiff-Appellant Mineral County and
Defendant-Appellant Walker Lake Working Group.

Wes Williams Jr., Law Offices of Wes Williams Jr. P.C.,
Schurz, Nevada, for Intervenor-Plaintiff-Appellant Walker
River Paiute Tribe.

Karen A. Peterson (argued), Justin M. Townsend, Kyle A.
Winter, and Willis M. Wagner, Allison MacKenzie Ltd.,
Carson City, Nevada, for Participant-Appellee United States
Board of Water Commissioners.

Elizabeth Ann Peterson, David L. Negri, Andrew “Guss”
Guarino, Katherine J. Barton, David C. Shilton, and William
B. Lazarus, Attorneys; John C. Cruden, Assistant Attorney
General; United States Department of Justice, Washington,
D.C.; for Amicus Curiae United States of America.

Jan Zabriskie, Deputy Attorney General; Annadel A.
Almendras and Tracy L. Winsor, Supervising Deputy
Attorneys General; Robert W. Byrne, Senior Assistant
Attorney General; Office of the Attorney General,
Sacramento, California; for Amicus Curiae California State
Water Resources Control Board.
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 17

                           OPINION

BYBEE, Circuit Judge:

    Water was plentiful when the first settlers arrived in
northwestern Nevada ten thousand years ago. Massive Lake
Lahontan spread from the Sierra Nevada to the Carson Sink,
the Black Rock Desert, and as far as California and Oregon.
“The world,” they said, “was all water.”1 Lake Lahontan has
slowly vanished over the years, and now survives only in the
form of a few desert lakes, including the subject of this case,
Walker Lake, the terminus of the Walker River.

   Walker Lake has suffered since the 1860s, when the
River’s waters were first diverted for agriculture, and the
Lake’s volume has plummeted precipitously in recent years.
In response, federal, state, tribal, local, and private
organizations and authorities have banded together to save the
Lake. The federal program at issue in this case is a voluntary
water rights leasing program managed by the National Fish
and Wildlife Foundation (“NFWF”) to convey water from
Walker River downstream to the Lake as part of the federal
Walker Basin Restoration Program. Like duck stamps and
emissions markets, NFWF’s program proposes to employ free
market forces to restore a natural balance between the
competing demands of agriculture and conservation.

   The Nevada State Engineer and the California State Water
Resources Control Board approved change applications for
NFWF’s program over the objections of farmers (“the
Farmers”) who claim injury to their water rights. The

    1
      NEVADA: A GUIDE TO THE SILVER STATE 218 (Nev. State Historical
Soc’y, Inc. 1940).
18 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

Farmers brought their complaints to the district court which,
as the Decree court, has maintained in rem jurisdiction over
the waters of Walker River since 1902 in accordance with the
Walker River Decree of 1936. The Decree court rejected the
state agency rulings, and found that the program, as proposed,
would injure the Farmers’ water rights.

    We examine two questions. First, did the Decree court
properly reject the state agency rulings—that NFWF’s
program would not cause any cognizable injury to the
Farmer’s water rights—based on its de novo review of the
Walker River Decree? Second, does the export restriction of
the Walker River Decree prohibit delivering water to Walker
Lake because it is “outside of” the Walker River Basin? We
answer both questions in the negative, reverse the judgment
of the Decree court, and remand for approval of the change
applications.

       I. FACTS AND PROCEDURAL HISTORY

A. The River and the Lake

    The Walker River consists of two forks that begin in
California and end in Nevada. The West Walker River
springs from the Emigrant Wilderness of Stanislaus National
Forest, and flows through Topaz Lake and north into
Nevada’s Smith and Mason Valleys. The East Walker River
springs from the Hoover Wilderness, passes through
Bridgeport Reservoir and into Nevada east of the Wovoka
Wilderness and Bald Mountain, before streaming into Mason
Valley. The forks join by Yerington and flow north to
Wabuska, before turning southeasterly through the land of the
Walker River Paiute Tribe (“the Tribe”). See United States
v. Walker River Irrigation Dist., 11 F. Supp 158, 161 (D.
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 19

Nev. 1935). From there, the River flows through Weber
Reservoir and Schurz, and into Walker Lake. See id. at
160–62.

    Walker Lake is about 13 miles long by 5 miles wide,
tucked against the east side of the Wassuk Range in Mineral
County, Nevada. It is one of the last few puddle remnants of
ancient Lake Lahontan.2 For centuries, the Lake served an
important ecological role as fishery for the native Lahontan
Cutthroat Trout—the state fish of Nevada—and as home and
resting grounds for hundreds of species, including fish,
insects, migratory birds, and wild horses.3 Human life at the
Lake is quite ancient as well, dating back to the spearheads in




    2
       NEVADA: A GUIDE TO THE SILVER STATE 218 (Nev. State Historical
Soc’y, Inc. 1940) (“In the steadfast intensity of its color and the beauty of
its setting Walker Lake is one of the most impressive lakes in the West.
As deeply and opaquely blue as the Mediterranean, under bright sunlight
it looks like a field of heavy liquid of unfathomable depth. . . . The lake,
impressive in its wild setting, has been the subject of numerous tall tales
and people are occasionally met who swear that they have glimpsed the
fabulous monster supposed to live in its blue depths.”).
    3
       In March 1885, a local publication “reported that Walker Lake was
so crowded with Lahontan cutthroat trout that during the middle of the day
long rows of the fish could be seen lying at the water’s edge on the sand
sunning themselves.” Gary A. Horton, WALKER RIVER CHRONOLOGY II-
12–13 (1996) (quoting the Walker Lake Bulletin), available at
http://images.water.nv.gov/images/publications/River%20Chronologies
/Walker%20River%20Chronology.pdf; see also Saxon E. Sharpe, et al.,
Desert Research Institute, Pub. No. 41231, THE WALKER BASIN, NEVADA
AND CALIFORNIA: PHYSICAL ENVIRONMENT, HYDROLOGY AND BIOLOGY
27–32 (2008) (“DRI Report”).
20 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

Mastodon bones and the petroglyphs carved by the Lake’s
northern shores.4

    By the early 1860s, miners looked to the mountains of the
Walker River Basin, seeking the same silver bonanzas
unearthed in the Comstock Lode near Lake Tahoe. Following
expanded mining operations, innovators in irrigation
technology arrived to make the desert bloom. They
succeeded. The Smith and Mason Valleys soon became the
picturesque and fertile agricultural region they are today.
More than half of the valley farmland is dedicated to alfalfa,
Nevada’s cash crop.

    As agriculture boomed, water flows to Walker Lake
diminished. See DRI Report, supra note 3, at 7. Between
1882 and 2007, the Lake’s volume plummeted from nine
million to two million acre feet and its salinity rose from
2,500 mg/L total dissolved solids (TDS) to 16,000 mg/L
TDS.5 Just a few years later in 2013, salinity exceeded
20,000 mg/L TDS.6 Lahontan cutthroat trout die in such a
saline environment; they and many other Lake residents have

    4
      NEVADA: A GUIDE TO THE SILVER STATE 24 (Nev. State Hist. Soc.,
Inc. 1940).
    5
      DRI Report at 7; Michael W. Collopy & James M. Thomas, Desert
Research Institute, RESTORATION OF A DESERT LAKE IN AN
AGRICULTURALLY DOMINATED WATERSHED: THE WALKER LAKE BASIN
ii–vii (2016), http://greatbasinresearch.com/walker/downloads/2016-
Walker-Report-without-appendices.pdf.
    6
      Erik Borgen, et al., Desert Research Institute, Ecosystem
Economics, Desert Research Institute, A SIMULATION MODEL FOR
EVALUATING WATER ACQUISITIONS TO REDUCE TOTAL DISSOLVED
SOLIDS IN WALKER LAKE 6 (2014), http://goo.gl/CWgQRg (indicating
TDS levels of 21,800 mg/L in Walker Lake in January 2014).
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 21

vanished. With the death of its aquatic life, migratory birds
have begun to abandon the Lake. Even the midges, side
swimmers, and damselflies have disappeared from the Lake
on a search for a more hospitable habitat.7 A scum now lines
the Lake’s receding shores.

B. The Decree and River Administration

    The action before us was filed in 1924, but traces its
history even further back, to 1902, when two cattle kings
realized that the Walker River Basin wasn’t big enough for
the two of them. Miller & Lux, the sprawling ranching
enterprise owned by Henry Miller, the “Cattle King of
California,” filed a quiet title action in Nevada district court
against 150 defendants, including arch-rival Rickey Land &
Cattle Co. owned by Thomas Rickey, the “Cattle King of the
West.” Miller & Lux sought a declaration of appropriative
water rights to a flow of 943.29 cubic-feet per second (cfs) of
the Walker River for use on its Nevada lands. Miller & Lux
v. Rickey, 127 F. 573, 575–76 (C.C.D. Nev. 1902). Rickey in
turn sued Miller in California state court, seeking his own
appropriative rights to a flow of 2,079 cfs for use on his
California lands. For years the parties disputed the Nevada
district court’s jurisdiction over California water rights,
pleading deficiencies, and application of the now-extinct local
action doctrine.

    The Nevada district court granted an antisuit injunction in
Miller’s favor, and we affirmed. Rickey Land & Cattle Co.
v. Miller & Lux, 152 F. 11, 22 (9th Cir. 1907). Because any
given usufructory right to a flow has an inherent connection

    7
      U.S. Fish & Wildlife Service, Walker Lake Ecosystem: Research
and Monitoring Summary Report 2006–2013 (2013).
22 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

to all other such rights in the same stream, appropriative
rights are conclusively established only by reference to all
other competing rights. We held that this naturally requires
exclusive jurisdiction over the entire res of the Walker River.
Id. at 14–19. The Supreme Court agreed. Rickey Land &
Cattle Co. v. Miller & Lux, 218 U.S. 258 (1910) (Holmes, J.).
After a decade of factfinding and hearings, the district court
issued a final decree settling the rights to the River. Pac.
Livestock Co. v. Thomas Rickey, In Equity No. 731, Final
Decree (D. Nev. 1919) (“the Rickey Decree”). Under the
Rickey Decree, the district court retained ancillary
jurisdiction to resolve future disputes over rights to Walker
River.

    The Walker River Irrigation District (“WRID”) was
established in 1919. It built two reservoirs in 1919 and 1921:
Topaz on the West Walker River, and Bridgeport on the East
Walker River.8 In 1924 the United States filed an action—In
Equity No. C-125—to quiet title to water rights to the Walker
River as trustee for the Tribe. After another decade of service
of process, the appointment of two Special Masters,
factfinding, and hearings, the court issued a final Decree on
April 14, 1936, amended in 1940 in ways not relevant here.

    Article I of the Decree recognizes the implied reserved
rights of the United States as trustee to the Tribe. See Winters
v. United States, 207 U.S. 564, 576–78 (1908). Article II
recognizes in their entirety the rights established in the 1919
Rickey Decree. Articles III–VII and IX provide for the flow
and storage rights of new private parties. Article VIII
recognizes WRID’s storage rights in the Topaz and

   8
     See NEV. REV. STAT. 539.013(2); James H. Davenport, NEVADA
WATER LAW 34 (2009).
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 23

Bridgeport reservoirs with respective priority dates of 1919
and 1921, and the attendant authority to distribute the water
stored there. Article X permits rightsholders to change the
manner, means, place or purpose of use, or the point of
diversion in the manner provided by law “so far as they may
do so without injury to the rights of other parties hereto, as
the same are fixed hereby.” Articles XI–XII provide that no
party may relitigate a claim to water rights in the Walker
River Basin, in the Nevada District Court or any other court,
that was litigated in the original case as of April 14, 1936.
Article XIII permits rightsholders to rotate their use of water,
i.e., collectively or individually rotate water usage for
improved efficiency, so long as no other rights are thereby
injured. Article XIV establishes the district court’s continued
jurisdiction “for the purpose of changing the duty of water or
for correcting or modifying this decree; also for regulatory
purposes, including a change of the place of use of any water
user,” but stipulates that “no water shall be sold or delivered
outside of the basin of the Walker River . . . .” Article XV
permits the Decree court to designate a water master, which
it did in 1937 by creating the U.S. Board of Water
Commissioners (“the Water Commissioners”)—a six-
member board overseen by a Water Master who apportions
and distributes the River’s waters. Finally, Article XVI sets
the irrigation season, which is today set at March 1 to October
31. By establishing its continued jurisdiction over the action
and the river, the district court became the “Decree court.”

C. The Walker Basin Restoration Program

    In 2002, Congress began to allocate funds for desert
terminal lake conservation. In 2009, it established the Walker
Basin Restoration Program “for the primary purpose of
restoring and maintaining Walker Lake.” Pub. L. No. 111-
24 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

85, §§ 207–08, 123 Stat. 2845, 2858–60 (2009); 16 U.S.C.
§ 3839bb-6. The Program is designed as a voluntary water
rights acquisition, trading, and leasing scheme to be jointly
administered by NFWF and WRID. Under the program,
NFWF leases or purchases flow and storage rights from
willing sellers, and uses those rights to convey water
downstream to feed the Lake. NFWF negotiated the program
details with the Tribe and WRID. WRID thereafter adopted
a regulation permitting rightsholders along the River to
participate in the program by leasing their claims for in-
stream use.

    NFWF purchased a number of claims with priority dates
from 1874 to 1906, which cumulatively provide for
7.745 cfs.9 In an effort to avoid injury to other rightsholders,
NFWF entered into stipulations with WRID, Lyon County,
the Tribe, the U.S. Department of the Interior Bureau of
Indian Affairs, and several private rightsholders. Per these
stipulations, NFWF agreed that program water would be
limited to the consumptive use portion of its decreed claims:
4.122 cfs out of 7.745 cfs.

     The consumptive use portion of a water right reflects the
amount of water that is actually used and consumed by
agriculture. When an upstream user appropriates water for
irrigation, some portion of the water—the non-consumptive
use portion—is not consumed by the crop and returns as
runoff to the river, and for another rightsholder’s use
downstream. For example, if Farmer A calls for a constant
flow of 10 cfs, some variable non-consumptive portion
returns to the river, say 4 cfs; the difference (6 cfs) is Farmer

     9
       These claims are identified as Decree Claims No. 23, 23-A, 35, 44,
67, and 89.
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 25

A’s consumptive use portion. The 4 cfs that returns to the
river is then available for Farmer B’s use. Effectively,
Farmer A has the right to call for 10 cfs, but is consuming
only 6 cfs. The consumptive and non-consumptive use
portions of any given water right will vary depending on crop
type, volume of irrigation water, and environmental factors.
In this example, if Farmer A seeks to change the claim’s use
by removing the entirety of the 10 cfs from the river, Farmer
B’s right is injured through deprivation of the non-
consumptive 4 cfs runoff. Determining whether a change to
Farmer A’s use will injure Farmer B’s right thus requires
determining how the change will affect the disposition of the
non-consumptive portion of Farmer A’s water right.

    Here, NFWF acquired the rights to call for 7.745 cfs.
NFWF’s hydrologists calculated a historic consumptive use
portion at a flow rate of 4.122 cfs. The difference, 3.623 cfs,
is the river runoff that was historically available to
downstream rightsholders. So as not to injure these
downstream claims, NFWF stipulated that it would call for
program water only in the flow amount of 4.122 cfs over the
course of the irrigation season, that is, approximately
53 percent of its total appropriative rights to 7.745 cfs.
NFWF further stipulated that the non-consumptive use
portion of its claims—a flow of 3.623 cfs—would be
administered by the Water Commissioners “in [their]
discretion . . . to avoid conflict with and injury to existing
water rights . . . and to mitigate hydrologic system losses.”

D. State Agency Rulings

   Under Article X of the Decree, as well as the 1953 Rules
and Regulations and the 1996 Administrative Rules and
Regulations, both of which were approved by the Decree
26 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

court, change applications—meaning any proposed changes
in purpose or place of use—must first be presented to the
state agencies for their approval.10 Applicants with Nevada
water rights submit applications with the Nevada State
Engineer, and applicants with California water rights submit
applications to the California State Water Resources Control
Board (“the California Control Board”).11

    1. The Nevada Ruling

    In 2011, NFWF applied with the Nevada State Engineer
for approval of two changes to its claims to a cumulative
7.745 cfs. First, NFWF requested changing the place of use
to “within the Walker River from the Weir Diversion
Structure through the USGS Wabuska Gauge, then through
Weber Reservoir into and including Walker Lake.” The
previous rightsholders had diverted the flow from the Weir
Diversion Structure into the West Hyland Ditch, downstream
from Yerington. Second, NFWF requested changing the
purpose of use from irrigation to wildlife purposes. See NEV.
REV. STAT. § 533.023. Effectively, NFWF sought approval
not to remove the water obtained through exercise of its water

    10
       See Administrative Rules & Regulations Regarding Change of
Point of Diversion, Manner of Use or Place of Use of Water of the Walker
River and its Tributaries and Regarding Compliance with California Fish
and Game Code Section 5937 and Other Provisions of California Law (as
amended through June 3, 1996) (“1996 Adminstrative Rules &
Regulations”).
    11
       The California Control Board only has authority over water rights
established after 1914, when the Board was created. See Nat. Res. Def.
Council v. Kempthorne, 621 F. Supp. 2d 954, 963 (E.D. Cal. 2009). In
1990, the Decree court appointed the Board as a Special Master, thus
authorizing the Board to make findings and recommendations as to pre-
1914 claims. See Fed. R. Civ. P. 53(b).
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 27

rights, so that water acquired from prior rightsholders may
flow, as it naturally would, into Walker Lake. Appropriative
rights in Nevada may be applied for a beneficial use in-
stream, regardless of whether the water flows to areas not
owned by the rightsholder. NEV. REV. STAT. § 533.040(2);
State Bd. of Agric. v. Morros, 104 Nev. 706, 766 (1988).

    The Water Commissioners and a group of private parties
(“the Farmers”) objected to both change applications. The
objecting Farmers hold so-called New Land Stored Water
Rights. That is, they operate farms on acres lacking
associated decreed claims, and instead have contractual
arrangements with WRID. They pay assessments to WRID,
which provides them with surplus reservoir water from Topaz
and Bridgeport. In other words, these are nondecreed rights
to reservoir water, not appropriative flow or storage rights.

     The Water Commissioners and Farmers pressed two
arguments. First, they argued that the changes would
impermissibly injure their New Land Stored Water Rights.
NFWF expects to call continuously for water during the
irrigation season when in priority, whereas the farmers who
previously owned the claims would on certain days
occasionally not call for water, such as on harvesting days,
which permitted the flow claims to be redirected by the Water
Master for reservoir storage. As such, the Farmers argued
that a continuous call would impermissibly injure their rights,
because it would ultimately decrease the amount of reservoir
water later available to meet their irrigation needs. Second,
they argued that Walker Lake lies outside of the Walker River
Basin. Thus, directing water to the Lake would violate
Article XIV of the Decree: “[N]o water shall be sold or
delivered outside of the basin of the Walker River.”
28 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

    The Nevada State Engineer, following public hearings,
rejected both arguments and granted NFWF’s application.
With respect to the question of injury, the Nevada State
Engineer found that under NFWF’s consumptive use
stipulation, no party would suffer injury. The State Engineer
considered NFWF in the position of “an irrigator who has a
decreed right to call for water on March 1st for the duration
of the irrigation season,” and “as the holder of claims senior
in priority to new lands storage rights, [NFWF] has the right
to seek a change in the manner and place of use.” The State
Engineer rejected any possibility that injury could occur
under NFWF’s stipulations, because it had dedicated the non-
consumptive portion of its decreed rights to the Water
Commissioners to remedy any injury or hydrological
efficiency loss caused by a continuous call of the
consumptive use portion of its decreed appropriative rights.
The State Engineer’s ruling adopted and incorporated the
consumptive use stipulations in their entirety. Finally, the
Engineer concluded that “Walker Lake is included in the
Walker River basin.”

   2. The California Ruling

    Likewise, WRID applied to the California Control Board
to temporarily change the place and purpose of use of its
decreed storage rights for Topaz and Bridgeport. This change
would allow WRID to distribute 25,000 acre-feet of stored
water per season to Walker Lake to meet the in-stream water
calls made by rightsholders within WRID who participate in
the program. The temporary changes were intended to give
WRID the time and flexibility to run the program for a trial
season while preparing its application for permanent changes.
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 29

   The California Control Board reviewed WRID’s
temporary one-year change application under California
Water Code § 1727. As relevant here, a party applying for a
temporary change must show that:

        [t]he proposed temporary change would not
        injure any legal user of the water, during any
        potential hydrologic condition that the board
        determines is likely to occur during the
        proposed change, through significant changes
        in water quantity, water quality, timing of
        diversion or use, consumptive use of the
        water, or reduction in return flows.

CAL. WATER CODE § 1727(b). See also CAL. WATER CODE
§1707(b)(2) (changes may not “unreasonably affect any legal
user of water”).

    The California Control Board overruled the objections of
the Water Commissioners and the Farmers. It found that
WRID had carried its burden because “petitioners do not
request any changes in the diversion of water to storage;
instead they only request changes in the place and purpose of
use upon release from storage.” By contrast, the Water
Commissioners and Farmers had failed to demonstrate “any
right, under contract or otherwise, to the stored water that will
be injured by the proposed temporary change.” As the
California Control Board explained, under California law,
changes to the purpose or place for which WRID releases
reservoir water under its control cannot give rise to an injury,
because WRID—not the Farmers—holds the statutory and
decreed right to distribute this water to legal appropriative
users. See Stevens v. Oakdale Irrigation Dist., 90 P.2d 58,
60–61 (Cal. 1939) (noting that a downstream user has no
30 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

right to a continued release of artificial flow). Accordingly,
the California Control Board concluded:

        It is not enough for a water user to show that
        it will receive less water as a result of the
        change. Instead, a water user claiming injury
        must demonstrate that it has a right to the
        greater amount of water claimed and that the
        proposed change will interfere with that
        right. . . . None of the commenters have
        demonstrated any right, under contract or
        otherwise, to the stored water that will be
        injured by the proposed temporary change.

Like the Nevada State Engineer, the California Control Board
rejected the argument that Walker Lake is not part of the
Walker River Basin, noting that the Lake sits within the same
hydrological drainage basin as the River.

    On motion for reconsideration, the California Control
Board affirmed its decision with an amendment noting that “a
stored water transfer . . . is not limited to the consumptive use
portion of the water right,” because “a downstream water user
who does not have a right to stored water cannot be injured
by changes in releases of the stored water.” See CAL. WATER
CODE § 1725 (permitting transfers of amounts that have been
“consumptively used or stored”).

E. Decree Court Ruling

    The Decree court rejected the Nevada State Engineer’s
and California Control Board’s rulings, refused to grant the
change applications, and remanded to the state agencies.
First, the court found that the stipulated program water
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 31

quantity would injure New Land Stored Water Rights,
because NFWF would not mimic the historical consumptive
use watering patterns of prior users who had occasionally
suspended calls for water on harvesting days. The court
reasoned that even if NFWF was

       limited to the historical use amount at any
       given time, it is likely to call for that amount
       on every day during the irrigation season,
       whereas its predecessors-in-interest did not in
       practice call for water during harvests and
       certain other periods, so the overall effect of
       the change will likely be to reduce the amount
       of water available for storage.

    The Decree court found that, although NFWF had
properly limited program water to the consumptive use
portion of its flow on a per second basis, NFWF would
continuously call for its claims to be serviced, and thus would
consume more water per season as compared to its
predecessors-in-interest. The court explained:

       A limit on the rate of consumption per second
       during days of use does not suffice to satisfy
       the no injury rule if the total amount of
       consumption per year is nevertheless
       increased. Where NFWF will in practice
       consume water at the same rate as its
       predecessors-in-interest but on more days
       throughout the year, its greater number of
       days of consumption per year could result in
       increased consumption per year (and therefore
       less available storage water available for
       junior users). . . . [T]he no injury rule
32 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

       prohibits NFWF from consuming more water
       per second or per year than its predecessors-
       in-interest.

The court remanded to the Nevada State Engineer to
determine the average number of days per year that each of
NFWF’s predecessors-in-interest historically called on their
respective claims and to limit approval of the change
application accordingly.

    As to the California Control Board’s ruling concerning
changes to WRID’s storage rights, the Decree court found
that changes to such rights must also be limited to the
consumptive use portion of the rights. In this regard, the
court held that the Farmers’ rights are injured where a change
application effectively reduces the amount of stored water
available to the users of those stored water rights. The
California Control Board had determined that because the
amount of storage water in the change would be limited to
water that would have otherwise been consumed or stored by
WRID, no injury would occur. The Decree court rejected this
finding, and remanded for the same historical consumptive
use calculations it had required with regard to the Nevada
State Engineer’s ruling. Specifically, the Decree court set out
a four-part procedure requiring the California Control Board
to: (1) identify each separate “piece” of program water
temporarily sold to WRID; (2) multiply those pieces by the
respective portions of those pieces historically attributable to
consumptive use; (3) calculate the sum of the consumptive
use pieces; and (4) limit the change applications accordingly.

    The Decree court also rejected both the Nevada and
California change applications on the grounds that in-stream
delivery of program water to Walker Lake would violate the
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 33

Decree’s export restriction, which prohibits delivering water
“outside of the basin of the Walker River.” The court found
that the “basin” comprises only agricultural lands and waters
named in the Decree. The court concluded, however, that
despite this, NFWF could still effectively send water to the
Lake by simply sending it to the most terminal point of the
River.

   These appeals followed. Appellants are NFWF, WRID,
the Nevada State Engineer, the Nevada Department of
Wildlife, Mineral County, and the Walker Lake Working
Group. Appellees are the Water Commissioners and the
Farmers. The United States and the California Control Board
appear as amici.

      II. JURISDICTION, CHOICE OF LAW, AND
               STANDARD OF REVIEW

A. Jurisdiction

    The Water Commissioners argue that, because the Decree
court merely remanded the change applications, did not fully
adjudicate the issues, and did not intend that its order be its
final act in the matter, we lack jurisdiction under 28 U.S.C.
§ 1291. Remand orders do not generally constitute
appealable “final decisions” under 28 U.S.C. § 1291. Alsea
Valley All. v. Dep’t of Commerce, 358 F.3d 1181, 1184 (9th
Cir. 2004); see also Dig. Equip. Corp. v. Desktop Direct, Inc.,
511 U.S. 863, 867 (1994).

    But a remand order may be considered final where
“(1) the district court conclusively resolves a separable legal
issue, (2) the remand order forces the agency to apply a
potentially erroneous rule which may result in a wasted
34 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

proceeding, and (3) review would, as a practical matter, be
foreclosed if an immediate appeal were unavailable.”
Collord v. U.S. Dep’t of the Interior, 154 F.3d 933, 935 (9th
Cir. 1998). These are not “strict prerequisites,” but merely
“considerations.” Sierra Forest Legacy v. Sherman, 646 F.3d
1161, 1175 (9th Cir. 2011).

    As to the first Collord consideration, the district court
resolved both questions at issue here: whether an injury can
accrue on these facts under the Walker River Decree, and
whether Walker Lake is “outside of the basin.” As to the
second Collord consideration, the Nevada State Engineer and
the California Control Board would be compelled to apply the
district court’s injury standard, which could as a practical
matter upset property rights elsewhere in the Walker River
Basin. The State Engineer explains that such a remand would
involve “a wasted proceeding [and] an unnecessary burden to
the State of Nevada’s resources, and force the [ ] Engineer to
apply the district court’s erroneous interpretation of Nevada
water law.” The State Engineer’s concerns are credible: the
remand order calls for a type of historical calculation that
would possibly require developing new methodologies for
measuring consumptive use. The third Collord consideration
is met where the agency is a party to the appeal. Alsea,
358 F.3d at 1184 (9th Cir. 2004). Otherwise, agencies “face
the unique prospect of being deprived of review altogether.”
Id. The third consideration is met here, as the Nevada State
Engineer appears as a party in these proceedings as
Respondent-Appellant. Although the California Control
Board is not a party to this appeal, it appears here as an
amicus and has fully briefed the issues.

    Beyond the Collord test, remand orders are sufficiently
“final” under § 1291, where the relief sought by appellants
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 35

cannot possibly be achieved through the district court’s
directions. Sierra Forest, 646 F.3d at 1174. Such
“meaningless remand[s]” are anathema to judicial economy.
Skagit Cty. Pub. Hosp. Dist. No. 2 v. Shalala, 80 F.3d 379,
384 (9th Cir. 1996). In the absence of appellate review, the
Nevada State Engineer and California Control Board may be
unable to grant any change applications that request
delivering water to Walker Lake, which the district court held
to be outside of the basin.

   The remand order is sufficiently final for our review
under 28 U.S.C. § 1291.

B. Choice of Law

     The Water Commissioners ask us to apply federal water
law. But there is no federal water law. Fundamental
principles of federalism vest control of water rights in the
states. See California v. United States, 438 U.S. 645, 677–79
(1978); United States v. Alpine Land & Reservoir Co.,
503 F.Supp 877, 885 (D. Nev. 1980). Decreed rights are
administered under applicable state law. See United States v.
Walker River Irrigation Dist., 11 F.Supp. 158, 165–68 (D.
Nev. 1935) (“The rights of the government, in its use of the
waters of the Walker river and its tributaries for purposes of
irrigation, like the rights of all other diverters in the Walker
River basin, are to be adjudged, measured, and administered
in accordance with the laws of appropriation as established by
the state of Nevada.”); see also Montana v. Wyoming,
563 U.S. 386, 377 n.5, 378 (2011); California Oregon Power
Co. v. Beaver Portland Cement Co., 295 U.S. 142, 163–64
n.2 (1935); United States v. Alpine Land & Reservoir Co.,
697 F.2d 851, 858 (9th Cir. 1983) (“[S]tate law will control
the distribution of water rights to the extent that there is no
36 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

preempting federal directive.”). Under the Decree, change
applications are to be treated “in the manner provided by
law.” The Decree presupposes state law in its entirety as to
both substance and procedure. See United States v. Orr
Water Ditch Co., 914 F.2d 1302, 1307–08 (9th Cir. 1990).

C. Standard of Review

   1. Review of the Decree Court

    We review the Decree court’s legal conclusions and
interpretations of the Decree de novo. United States v. Orr
Water Ditch Co., 256 F.3d 935, 945 (9th Cir. 2001); Orr
Water Ditch, 914 F.2d at 1307. Our review of mixed
questions of law and fact depends on the nature of the issue.
“A mixed question asks whether ‘the historical facts . . .
satisfy the statutory standard, or to put it another way,
whether the rule of law as applied to the established facts is
or is not violated.’” U.S. Bank Nat’l Ass’n v. Village at
Lakeridge, LLC, 583 U.S. ____ (2018) (slip op., at 7)
(quoting Pullman-Standard v. Swint, 456 U.S. 273, 289, n. 19
(1982)). “When an ‘issue falls somewhere between a pristine
legal standard and a simple historical fact,’ the standard of
review often reflects which ‘judicial actor is better
positioned’ to make the decision.” Id., slip op. at 8 (quoting
Miller v. Fenton, 474 U.S. 104, 114 (1985)). In reviewing
change application to water rights, the Decree court’s
activities are primarily legal—the evidence and facts
underlying the change applications are elicited and marshaled
in proceedings before the respective state agencies. The
Decree court then reviews those agencies’ rulings with at
least some deference to questions of fact and law, as
discussed below. We will review de novo the Decree court’s
review of the state agencies. Where the Decree court has
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 37

entered its own findings of fact, we review those for clear
error.

   2. Deference to State Agencies

    The parties dispute whether and to what degree the
Decree court was required to defer to the state agency
findings and rulings in their adjudication of change
applications. As we have previously explained, the Decree
court applies state water law. When it does so, the Decree
court must afford the same level of deference state courts
would afford the state agencies. See Orr Water Ditch,
914 F.2d at 1307–08.

    Under Nevada law, the “decision of the State Engineer is
prima facie correct, and the burden of proof is upon the party
attacking the decision.” NEV. REV. STAT. § 533.450(10); see
State Eng’r v. Morris, 819 P.2d 203, 205 (Nev. 1991)
(“[D]ecisions of the State Engineer are presumed to be
correct upon judicial review.”). With respect to findings of
fact, the Nevada Supreme Court has stated that “neither the
district court nor this court will substitute its judgment for
that of the State Engineer: we will not pass upon the
credibility of the witnesses nor reweigh the evidence, but
limit ourselves to a determination of whether substantial
evidence in the record supports the State Engineer’s
decision.” Id. (citation omitted). As to matters of law, the
State Engineer’s interpretation of legal questions and Nevada
statutes is “persuasive,” but not controlling. Orr Water Ditch,
256 F.3d at 945; State v. Morros, 766 P.2d 263, 266 (Nev.
1988).

   California courts also exercise deferential review and
must consider:
38 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

       (1) whether the [Board] has proceeded
       without, or in excess of jurisdiction;
       (2) whether there was a fair trial; and
       (3) whether there was any prejudicial abuse of
       discretion. Abuse of discretion is established
       if the [Board] has not proceeded in the manner
       required by law, the order or decision is not
       supported by the findings, or the findings are
       not supported by the evidence.

CAL. CIV. PROC. CODE § 1094.5(b); see State Water Res.
Control Bd. Cases, 39 Cal. Rptr. 3d 189, 226 (Cal. Ct. App.
2006). A court “review[s] the record to determine whether
the [Board’s] factual findings are supported by substantial
evidence, resolving all evidentiary conflicts and drawing all
legitimate and reasonable inferences in favor of the [Board’s]
decision.” Millview Cty. Water Dist. v. State Water Res.
Control Bd., 177 Cal. Rptr. 3d 735, 746 (Cal. Ct. App. 2014)
(citation omitted). Like Nevada courts, California courts
review the Board’s legal conclusions independently, “giving
deference to the determination of the agency appropriate to
the circumstances of the agency action.” Phelps v. State
Water Res. Control Bd., 68 Cal. Rptr. 3d 350, 360 (Cal. Ct.
App. 2007) (emphasis in original) (citation omitted).

    The Farmers and Water Commissioners argue that
because the Decree court appointed the California Control
Board as Special Master under FED. R. CIV. P. 53(b) in 1990,
the Decree court may review all aspects of the Board’s
rulings de novo and that the Decree court’s 1996
Adminstrative Rules and Regulations so provide. See FED. R.
CIV. P. 53(f)(3)–(4); 1996 Administrative Rules &
Regulations § 7.9; see also id. § 7.10 (“In reviewing any
report of the Water Resources Control Board, the court . . .
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 39

shall not be limited by the ‘clearly erroneous’ standard.”). As
we have previously explained, supra note 11, the Decree
court appointed the California Control Board as a Special
Master over pre-1914 appropriative rights, over which the
Board lacks statutory authority. WRID’s storage rights did
not arise until the construction of the reservoirs in 1919 and
1921, and thus the California Control Board had authority to
rule on WRID’s change applications. Here, the Board issued
its Order and Modified Order in its role as state agency and
submitted a report to the Decree court in its role as Special
Master. Insofar as the California Control Board exercised
lawful agency authority under California law in adjudicating
change applications to WRID’s post-1914 water rights, the
Decree court should have afforded the Board the same degree
of deference that California courts do.12

                       III. ANALYSIS

    Appellants claim two errors. First, they argue that
NFWF’s promise to limit its in-stream use to the historic
consumptive use portion of its claims precludes any
possibility of injury to other rightsholders. Second, they
argue that the court erred by interpreting the Decree’s export
restriction as a prohibition on delivering water to the Lake.
We address each in turn.

A. Injury

    Article X of the Decree states:



    12
      On remand, the Decree court may wish to consider whether the
1996 Administrative Rules and Regulations need to be clarified to
conform to this opinion and to Nevada and California law.
40 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

       Any of the said parties shall be entitled to
       change the manner, means, place or purpose
       of use or the point of diversion of the said
       waters or any thereof in the manner provided
       by law, so far as they may do so without
       injury to the rights of other parties hereto, as
       the same are fixed hereby.

This “no-injury” provision in the Decree recognizes the duty
of each appropriator to manage its water use so as to avoid
injury to other appropriators, including junior appropriators.
The Nevada State Engineer and the California Control Board
both concluded that because NFWF agreed to limit program
water to the consumptive use portion of the claims, there is no
material change in its usage and no other rightsholders will be
injured. The Decree court rejected this conclusion. We
conclude that the Decree court failed to defer to the findings
and conclusions of the state agencies. To the extent the
Decree court entered its own findings, we conclude that those
findings are clear error.

   1. Principles

    Almost all states employ one of three water rights
regimes: a regime of riparian rights common in the East, a
regime of rights acquired by prior appropriation common in
the West, or a hybrid system such as in California. While
riparian rights inhere in the land appurtenant to the waterway,
vary in quantity based on flow, remain vested even if unused,
and are subject to reasonable use, appropriative rights are
untethered from land ownership, are acquired and maintained
by active beneficial diversion of water, provide for a fixed
flow of water, and are tiered as senior and junior rights based
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 41

on chronological claim priority. As the Supreme Court
explained,

            The right to water by prior appropriation
       . . . is limited in every case, in quantity and
       quality, by the uses for which the
       appropriation is made. . . . The appropriation
       does not confer such an absolute right to the
       body of the water diverted that the owner can
       allow it, after its diversion, to run to waste and
       prevent others from using it for mining or
       other legitimate purposes.

       ...

           What diminution of quantity . . . will
       constitute an invasion of the rights of the first
       appropriator will depend upon the special
       circumstances of each case, considered with
       reference to the uses to which the water is
       applied.

Atchison v. Peterson, 87 U.S. 507, 514–15 (1874). See also
Colorado v. New Mexico, 459 U.S. 176, 179 n.4 (1982).

    In Nevada, as elsewhere, a water right is the “right to
divert water . . . for beneficial use from a natural spring or
stream.” Application of Filippini, 202 P.2d 535, 537 (Nev.
1949). Perfecting and maintaining appropriative water rights
require an act of diversion—or, as here, an act of so-called
non-diversion—and beneficial use of the water. See, e.g.,
Prosole v. Steamboat Canal Co., 140 P. 720, 722 (Nev. 1914)
(superseded by statute on other grounds); Strait v. Brown,
16 Nev. 317, 324 (1881); Lobdell v. Simpson, 2 Nev. 274, 279
42 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

(1866); see also Nebraska v. Wyoming, 325 U.S. 589, 614
(1945) (“The water right is acquired by perfecting an
appropriation, i.e., by an actual diversion followed by an
application within a reasonable time of the water to a
beneficial use.”). As with senior and subordinated debt, a
senior appropriative right, i.e., the right with an earlier
priority date, is superior to all junior rights. When there is
insufficient water to fill all claims, the senior right is satisfied
before others. DAVID H. GETCHES, WATER LAW 77–80 (4th
ed. 2009).

   The no-injury rule of Article X of the Decree is a
codification of a basic principle of prior appropriation:

        [T]he no-injury rule prevents appropriators
        from making certain water-right changes that
        would harm other appropriators . . . . Because
        each new appropriator is entitled to the stream
        as it exists when he finds it, the general rule is
        that “if a change in these conditions is made
        by [a senior] appropriator, which interferes
        with the flow of the water to the material
        injury of [the junior appropriator’s] rights, he
        may justly complain.”

Montana, 563 U.S. at 378 (alterations in original) (quoting
2 C. Kinney, LAW OF IRRIGATION AND WATER RIGHTS § 803,
at 1404 (2d ed. 1912)); see also Wyoming v. Colorado,
298 U.S. 573, 584 (1936) (“[T]he use of the water may be
changed from the irrigation of one tract to the irrigation of
another, if the change does not injure other appropriators.”).
Alleged injuries are analyzed on a case-by-case basis with a
primary focus on the particular equities at issue. Atchison,
87 U.S. at 514–15.
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 43

    Nevada has codified its no-injury rule. NEV. REV. STAT.
§ 533.370 (requiring an injury analysis in change application
adjudications to determine whether “the proposed use or
change conflicts with [other] existing water rights” and
prohibiting changes that will “adversely affect the cost of
water for other holders of water rights in the district”). In
determining whether a proposed change application causes
injury,

         [t]he State Engineer may consider the
         consumptive use of a water right and the
         consumptive use of a proposed beneficial use
         of water in determining whether a proposed
         change in the place of diversion, manner of
         use or place of use [causes injury]. The
         provisions of this section [m]ust not be
         applied by the State Engineer in a manner that
         is inconsistent with any applicable federal or
         state decree concerning consumptive use.

NEV. REV. STAT. § 533.3703(1). Cf. Pyramid Lake Paiute
Tribe of Indians v. Nev. Dep’t of Wildlife, 724 F.3d 1181,
1185 n.4 (9th Cir. 2013) (“[C]hange in manner of use
applications from use for irrigation to any other use . . . shall
be allowed only for the net consumptive use of the water as
determined by this Decree.”) (quoting Administrative
Provision VII of Alpine Decree).13

    13
       The Orr Ditch decree court’s definition of injury is also consistent
with these principles:

         An “injury” to a Decreed water right is not shown
         merely by establishing a shortage of water because an
         owner of a water right can be shorted water without
         violating the Orr Ditch Decree. Similarly, alterations of
44 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

     California law similarly recognizes the no-injury rule and
takes into account the effect of consumptive use. The
California Control Board “shall approve a temporary change
if it determines that a preponderance of the evidence shows”
that the “proposed temporary change would not injure any
legal user of the water” or “unreasonably affect fish, wildlife,
or other instream beneficial uses.” CAL. WATER CODE
§ 1727(b); see also CAL. WATER CODE § 1726(e) (“[T]he
proposed change must involve only the amount of water that
would have been consumptively used or stored in the absence
of the temporary change.”). “[I]n determining whether the
petitioned changes to the licenses of the irrigation districts
would cause ‘substantial injury’ to or would ‘unreasonably
affect’ riparian and appropriative users in the [water at
issue],” the California Control Board should focus “on the
effect of those changes on the rights of those users.” State
Water Res. Control Bd. Cases, 39 Cal. Rptr. 3d at 243. “[A]
person who claims injury from a change in the terms of a
permit to appropriate water must show the change will
interfere with his or her right to use the water, whatever the
source of that right may be.” Id. at 293. California law
protects the continuation of a river’s natural flow against a


         historical flows do not, of themselves, establish injury.
         Rather, an injury occurs when the owner receives less
         water than the amount to which the owner is legally
         entitled, which determination requires consideration not
         only of the amount of the water duty, but also its
         priority, and certain other conditions affecting the river
         system.

Orr Water Ditch, 2014 WL 4832052, at *7 (D. Nev. Sept. 30, 2014); see
also United States v. Gila Valley Irrigation Dist., 859 F.3d 789, 801 (9th
Cir. 2017) (“Possible injury should be analyzed by comparing the impact
of a proposed change against a baseline of existing conditions.”) (citation
and quotation omitted).
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 45

change in use by another appropriator, but does not assure the
release of stored water, as such water constitutes an artificial
supply and flow. Stevens, 90 P.2d at 60–61; see also State
Water Res. Control Bd. Cases, 39 Cal. Rptr. 3d at 238–46.

    As we have previously explained, when water is
withdrawn from a river system for irrigation, some of that
water will return to the system through drainage. The
consumptive use portion of a water right reflects the amount
of water that a farmer’s crops actually consume.14 The rest of
the water, the non-consumptive use portion, drains as runoff
to the river or otherwise remains in the basin’s
hydroecosystem for subsequent use by downstream users.
See Alpine Land & Reservoir Co., 697 F.2d at 857 n.4.
Consumptive use is not a measure of how farmers call for
water, but rather the “quantity of water actually consumed by
crop growth.” Pyramid Lake Paiute Tribe of Indians,
724 F.3d at 1185. When rightsholders change the purpose or
place of use of a water right, they must consider how that
change will affect fellow appropriators. Suddenly drawing
more water from the river for a new and unannounced
purpose can diminish one’s downstream neighbor’s rights to
the runoff. The nonconsumptive portion of an appropriation
must be considered, because a junior rightsholder “is entitled
to the stream as it exists when he finds it.” Montana,
563 U.S. at 378 (quoting 2 KINNEY § 803, at 1404); see
GETCHES, WATER LAW at 178.



    14
        The U.S. Geological Survey (USGS) defines consumptive use as
“the part of water withdrawn that is evaporated, transpired, incorporated
into products or crops, consumed by humans or livestock, or otherwise not
available for immediate use.” USGS, WATER USE TERMINOLOGY,
https://water.usgs.gov/watuse/wuglossary.html.
46 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

   2. Application

     When NFWF acquired decreed appropriative rights with
priorities from 1874 to 1906, it acquired the right to a flow of
7.745 cfs. But NFWF’s prior appropriators did not consume
all 7.745 cfs. Their consumptive use was only 4.122 cfs, the
remaining 3.623 cfs finding its way back to the Walker River
as runoff. NFWF agreed, consistent with the historic use of
the prior rightsholders, to divide its right into a consumptive
use portion of 4.122 cfs to be used as program water, and the
remaining non-consumptive use portion of 3.623 cfs to be
used to mitigate hydrological system loss.

    The Nevada State Engineer and the California Control
Board approved NFWF’s and WRID’s proposed change
applications, but the Decree court refused to approve the
changes. According to the court, NFWF’s changes would
“injure other users with decreed rights.” The court
acknowledged that NFWF would take only “the former
consumptive use amount,” but found that NFWF was “likely
to call for that amount on every day during the irrigation
season, whereas its predecessors-in-interest did not in
practice call for water during harvests and certain other
periods.” Specifically, the court was referring to the
historical harvest days identified in the evidence submitted to
the Nevada State Engineer, indicating a total of four alfalfa
harvest days in the Mason Valley beginning around June 3
each year. In the Decree court’s view, because “the no injury
rule prohibits NFWF from consuming more water per second
or per year than its predecessors-in-interest did,” “the overall
effect of the change will likely be to reduce the amount of
water available for storage.” The Decree court was
concerned that, although NFWF’s flow rate was consistent
with historic usage, the total amount of water to be taken by
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 47

NFWF would exceed the water historically called for by its
predecessors-in-interest:

       The Court finds that under the no injury rule,
       the changes must be limited not only to the
       prior consumptive use per second, but also to
       the prior total amount of consumptive use per
       year. A limit on the rate of consumption per
       second during days of use does not suffice to
       satisfy the no injury rule if the total amount of
       consumption per year is nevertheless
       increased. Where NFWF will in practice
       consume water at the same rate as its
       predecessors-in-interest but on more days
       throughout the years, its greater number of
       days of consumption per year results in
       increased consumption per year (and therefore
       less available storage water available for
       junior users).

    Water can be calculated as a flow or as a volume.
Appropriative flow rights under the Decree are calculated in
cubic-feet per second (cfs), while annual consumptive use is
calculated as a volume in acre-feet per acre per irrigation
season (afa). See BECK & KELLEY, 1-1 WATERS AND WATER
RIGHTS § 1.02 (2017). The Net Irrigation Water Requirement
(NIWR) of alfalfa in the Mason Valley is 3.1 afa. See J.L.
Huntington & R.G. Allen, Nevada Department of
Conservation & Natural Resources, EVAPOTRANSPIRATION
AND NET IRRIGATION WATER REQUIREMENTS FOR NEVADA
215 (2010) (“NIWR Report”). The NIWR is synonymous
with consumptive use per year. This figure means that over
the course of an irrigation season, one acre of alfalfa in the
48 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

Mason Valley will consume 3.1 acre-feet of irrigation
water—anything beyond that is runoff.15

    NFWF’s stipulations contained three provisions pertinent
here. First, NFWF stipulated to an annual consumptive use
volume of 3.1 acre-feet of water per acre (afa), which is the
total consumptive requirement for an acre of alfalfa, the crop
grown by NFWF’s predecessors-in-interest. Second, out of
NFWF’s total rights to 7.745 cfs, only 4.122 cfs—the
consumptive use portion of the flow—would be used as
program water. Third, the remaining portion of its
rights—the non-consumptive use portion of
3.623 cfs—would be at the Water Commissioners’ disposal
to mitigate any possible injury to other water rights, including
the storage rights belonging to WRID.

    The Nevada State Engineer received testimony on the
consumptive use as measured per second (cfs) and annually
(afa). And, specifically, that testimony addressed whether
NFWF’s proposed use accounted for the harvest days of its
predecessors-in-interest. The Nevada State Engineer credited
the testimony of hydrologist Dr. Greg Pohll, who stated that
the 3.1 afa in the NIWR included both “variable start dates
for irrigation in Mason and Smith Valleys, and individual
simulated cuttings as part of the calculations.” Similarly, the
Engineer heard from David Yardis, Director of the Walker

    15
        The NIWR of 3.1 for alfalfa in the Mason Valley was calculated
using evapotranspiration parameters such as crop height, radiation, soil
heat flux densities, temperatures, wind speeds, saturation vapor pressures,
pressure-temperature curves, precipitation, other atmospheric and
psychrometric variables, as well as simulated green-ups and harvest
cuttings. NIWR Report at 3–9, 27, 44–50. The NIWR of 3.1 afa was
derived from mean evapotranspiration values from 1965–2007. Id. at 68,
215.
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 49

Basin Restoration Program, who “reiterated Dr. Pohll’s
testimony that the consumption figures of 3.10 acre-feet per
acre accounted for variable weather situations,
[evapotranspiration], and regular cuttings.”16 The Nevada
State Engineer found that “Dr. Pohll’s interpretation of the
methodology of the NIWR is correct, and that the NIWR
consumptive use figure of 3.10 acre-feet per acre in the
Walker River Basin for alfalfa takes into account a variable
irrigation start date and multiple simulated cuttings during the
irrigation season.” The Nevada State Engineer found that the
Commissioners’ and the Farmers’ arguments “concerning
impacts to new land storage rights are addressed within the
calculation of the 3.10 acre-feet per acre consumptive use
amount.”

   The Decree court failed to defer to the findings of the
Nevada Engineer, whose findings are presumed correct. NEV.


   16
        The NIWR itself accounts for variable irrigation start dates:

               Defining the length of the growing season, time to
          effective full cover, and harvest dates are all important
          aspects of estimating [actual evapotranspiration] and
          the NIWR. . . .

               Calibration of [Cumulative Growing Degree Days],
          [the thirty-day moving average of mean daily air
          temperature], percent time from effective full cover to
          harvest days, and days after effective full cover to
          harvest, for simulating greenup and harvest dates was
          ultimately accomplished by minimizing the error in
          simulated vs. documented/typical greenup, planting,
          and harvest dates outlined in Table 4, which lists the
          results and specific information used in the calibration.

NIWR Report at 42–44.
50 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

REV. STAT. § 533.450(9)–(10); Alpine Land & Reservoir Co.,
919 F. Supp. at 1474; Morris, 819 P.2d at 205. Once we
consider the record before the Nevada State Engineer, the
Decree court’s concerns are unfounded, and the Nevada State
Engineer properly found that “a transfer [to NFWF] limited
to the consumption portion . . . would avoid conflict and
injury to other existing water rights.” Because these findings
are supported by substantial evidence and the State Engineer
applied the correct legal rule, the Engineer’s conclusions are
entitled to deference. It was error for the Decree court to
reject those conclusions.

     To the extent the Decree court made its own findings of
fact, those findings are clearly erroneous. The Decree court
found that there was a difference between NFWF’s proposed
per second consumption rate (cfs) and its annual consumptive
volume (afa). The Nevada State Engineer concluded there
was not, and the math bears this out. NFWF’s stipulated flow
of 4.122 cfs, if called for continuously over the irrigation
season, does not exceed the annual consumptive use volume
of 3.1 afa. They are identical. We convert the stipulated flow
and consumptive use volume into total acre-feet of water per
irrigation season, and compare. To determine the total
volume of water delivered to Walker Lake if the stipulated cfs
is continuously called for, we multiply the stipulated flow
(4.122 cfs) by seconds in a day (86,400 s), and then by days
in the irrigation season (245 d),17 which produces




    17
      The irrigation season is 245 days from March 1 to October 31. See
Decree Art. XVI, amended (1940); Walker River Irrigation District,
RULES AND REGULATIONS GOVERNING THE DISTRIBUTION AND USE OF
WATER § 9.1, http://www.wrid.us/WRID/rulesandregs.
    NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 51

87,254,496 cubic-feet or 2,003.091 acre-feet.18 To determine
the total volume of irrigated water previously consumed per
irrigation season in acre-feet, we multiply the total acreage of
farmland whose decreed claims NFWF acquired
(646.160 acres), by the consumptive use by each acre
(3.1 afa). That produces a volume of 2,003.096 acre-feet of
water. If NFWF were to call for a continuous flow of its
maximum diversion rate of 4.122 cfs during the entire
irrigation season, the total amount of program water will be
0.005 acre-feet less than that consumptively used by its
predecessors-in-interest, which appears to be a rounding
error. Whether we calculate the program water as a rate (cfs)
or as a volume (afa), the quantities are the same. The Decree
court erred in when it concluded that the Nevada State
Engineer had not accounted for the harvest days.

    The Decree court’s rejection of the California Control
Board’s ruling was also error. WRID holds combined
licenses to store between 71,310 and 76,060 acre-feet of
water annually. It requested permission to use up to
25,000 acre-feet of water stored at the Bridgeport and Topaz
Reservoirs for in-stream use at Walker Lake. The California
Control Board approved the temporary permit, finding that
the amount of storage water in the transfer would be limited
to water that would otherwise be consumed or stored by
WRID, and thus no injury would occur. The Board found
that the Farmers objecting to WRID’s proposed change did
not have “any right under contract or otherwise, to the stored
water,” and thus could not be injured by the proposed change
in use. According to the Board, stored water is considered an



    18
       One acre-foot equals 43,560 cubic-feet. 87,254,496 divided by
43,560 equals 2,003.091.
52 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

artificial flow, and a downstream user has no right to the
discharge of stored water.

    The Decree court rejected the Board’s conclusions and
substituted its own conclusion that WRID’s temporary permit
to release stored water would injure “junior storage right[s]”
because WRID was “reduc[ing] stored water that would
otherwise be available to a user with storage rights.” The
court concluded that WRID’s proposal thus ran afoul of the
“no injury rule.” The court’s reliance on injury to “junior
storage right holders” is misplaced, both as a matter of the
Decree and California law. The Decree’s “no injury” rule
refers to “injury to the rights of other parties hereto, as the
same are fixed thereby.” Art. X (emphasis added). The no
injury rule does not extend to persons who do not have
decreed rights. Under Section VIII of the Decree, WRID is
declared to be “the owner of the flow and use of the flood
waters of East Walker River and its tributaries for storage in
Bridgeport Reservoir”; it likewise is the owner of the flood
waters of the West Walker River for storage in the Topaz
Reservoir. Any permits issued to WRID by the California
Control Board are “subject to vested prior rights” and stored
water must be distributed “to the lands in the District entitled
thereto, in accordance with their respective rights.”
Accordingly, the Decree gives WRID distribution rights over
the stored water, which it must exercise consistent with the
Decree and Nevada law.              The Decree recognizes
appropriative and storage rights in numerous private parties
throughout the Walker River Basin, but it gives WRID alone
the right to store and distribute the waters of Topaz and
Bridgeport.

    California’s no injury rule is codified in various sections
of California’s Water Code, each of which prohibits injury to
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 53

a “legal user of water.” CAL. WATER CODE §§ 1701(b)(2),
1725, 1727(b)(1) (emphasis added). But under California
law, “appropriators have no right to water stored by the
irrigation districts.” State Water Res. Control Bd. Cases,
39 Cal. Rptr. 3d at 244. “When [ ] stored water is released to
customers, it is not part of the river’s natural flow and does
not count towards the appropriators current allocation of river
water.” Id.; see also Stevens, 9 P.2d at 61 (“The producer of
an artificial flow is for the most part under no obligation to
lower claimants to continue to maintain it. . . . [L]ower users
will not have acquired a right against him, either by
appropriation or prescription, to continued augmentation of
the natural volume of the stream”); Lindblom v. Round Valley
Water Co., 173 P. 994, 997 (Cal. 1918) (holding that an
appropriator “cannot require [a reservoir owner] to discharge
any water into the stream during those months in which there
would be no flow if no dam had ever been built.”).

    We know of no principle in California law that recognizes
“storage rights” in a reservoir, outside of the reservoir owner.
Insofar as the Farmers complaining here hold no decreed
rights to the waters WRID is storing, they cannot claim any
legal injury caused by changes to how and where WRID
distributes flow to the rightsholders of decreed, appropriative
rights. As the California Control Board explained “[i]t is not
enough for a water user to show that it will receive less water
as a result of the change. Instead, a water use claiming injury
must demonstrate that it has a right to the greater amount of
water claimed and that the proposed change will interfere
with that right.” The Control Board found that “[n]one of the
[objectors] have demonstrated any right, under contract or
otherwise, to the stored water that will be injured by the
proposed temporary change,” and that the “[l]andowners in
[WRID] will continue to be allocated their portion of the
54 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

stored water.” It thus concluded that “[o]nce the water is
diverted to storage in a manner consistent with water right
priorities, water stored in Topaz and Bridgeport Reservoirs is
previously stored water to which the [objectors] have not
demonstrated any legal interest.” In sum, the Control Board
found that the proposed changes “would not injure any legal
use of the water.” That finding is consistent with the Decree
and in accord with California law, and it was error for the
Decree court to refuse to approve the California Control
Board’s Report approving WRID’s change application.

B. The Basin

    Under Article XIV of the Decree, “no water shall be sold
or delivered outside of the basin of the Walker River.” The
Water Commissioners argue, and the Decree court held, that
delivering river water to Walker Lake would violate this
export restriction, because the Lake is “outside of the basin of
the Walker River.” The court’s interpretation rested on
several grounds: that there are no decreed rights to
appropriate water from the Lake; that the Decree does not
mention the Lake, but rather mentions other lakes as
tributaries to the River; and that the Decree concerns
appropriative rights only to the River and its tributaries, but
not the Lake. On this basis the court held that “basin,” as
used in the export restriction, unambiguously refers only to
those agricultural lands that beneficially use the River’s
waters and those waters that are mentioned by name in the
Decree, but not the Lake itself. By contrast, both the Nevada
State Engineer and the California Control Board found that
Walker Lake was within the Walker River Basin.

   The Walker River Decree is a partially stipulated decree,
and so we interpret its provisions in a manner consistent with
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 55

the entirety of the decree, and without the aid of extrinsic
materials unless the provisions are ambiguous. Wackerman
Dairy, Inc. v. Wilson, 7 F.3d 891, 897 n.13 (9th Cir. 1993).
Provisions are ambiguous where they are subject to two or
more reasonable interpretations. See Frei ex rel. Frei v.
Goodsell, 305 P.3d 70, 73–74 (Nev. 2013); State v. Cont’l
Ins. Co., 281 P.3d 1000, 1004 (Cal. 2012).

     The district court correctly noted that the export
restriction ensures that the basin’s waters remain in the basin
for beneficial use by appropriative rightsholders. Such a
protectionist measure appears elsewhere in water law as a
mechanism to preserve water resources for local use. See,
e.g., COLO. REV. STAT. § 37-81-101 (prohibiting the export
of river waters outside Colorado to ensure “adequate supplies
of water necessary to insure the continued health, welfare,
and safety of all its citizens”).

    We do not think there is any ambiguity in the phrase
“basin of the Walker River.” Consider the plain hydrological,
geomorphic, geographic, and everyday meaning of the word
“basin.” A “basin,” as we commonly use that word, is simply
the geographic area that is coextensive with a river system’s
hydrological drainage. The Decree court itself used the term
“basin” according to this plain hydrological and geographic
meaning, when it opened its Order by observing that the
Walker River Basin is approximately 4,050 square miles
“from its origins in the southwestern elevations of the Sierra
Nevada Mountains to its terminus, Walker Lake.”

    Even if the term “basin” were ambiguous, interested
extrinsic sources support the interpretation urged by NFWF
and found by the Nevada State Engineer and the California
Control Board. The State of Nevada refers to the Walker
56 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

River Basin, including Walker Lake, as “Hydrographic
Region No. 9.”19 The USGS calls it “Accounting Unit
160503,” composed of hydrological sub-units East Walker,
West Walker, Walker, and Walker Lake.20 And the USGS’s
Nevada Water Science Center places the Lake at “the lowest
point in the basin.”21 Additionally, the Nevada Supreme
Court views the Lake as part of the Walker River system and
subject to the Decree court’s jurisdiction.22 The Decree court
itself once noted that the Basin includes “sub-basin[] . . .
110B,” which the State of Nevada titled the “Lake Subarea.”23
Congress understood no differently when it enacted the
legislation to save Walker Lake under the aptly titled Walker
Basin Restoration Program. Pub. L. No. 111-85, §§ 207–08,
123 Stat. 2845, 2858–60 (2009).




    19
        See Nev. Dep’t of Conservation & Nat’l Res., DESIGNATED
GROUNDWATER BASINS OF NEVADA (2017),
http://water.nv.gov/mapping/maps/designated_basinmap.pdf.
    20
        Paul R. Seaber, et al., USGS, HYDROLOGIC UNIT MAPS 54 (1994),
https://pubs.usgs.gov/wsp/wsp2294/pdf/wsp_2294.pdf; id., Plate 1,
https://pubs.usgs.gov/wsp/2294/plate-1.pdf.
     21
        Kip K. Allander, et al., USGS, United States Dep’t of the Int.,
EVAPOTRANSPIRATION FROM THE LOWER WALKER RIVER BASIN, WEST-
C E N T RAL N EVAD A , W ATER Y EARS 2005-07 5 ( 20 0 9) ,
https://pubs.usgs.gov/sir/2009/5079/pdf/sir20095079.pdf.
    22
         Mineral County, 20 P.3d at 805–06.
    23
       Compare United States v. Walker River Irr. Dist., 2002 WL
35634154, at *1 (D. Nev. Apr. 26, 2002), with Nev. Dep’t of Conservation
& Nat’l Res., DESIGNATED GROUNDWATER BASINS OF NEVADA (2017),
supra note 19.
   NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS 57

    The Commissioners point to a 1935 opinion of the Decree
court, in which Judge St. Sure described his happy “tour of
the Walker River basin” and referred to his visit to “the
valleys, meadows, the Walker Indian Reservation, the storage
reservoirs, a site of a proposed reservoir, and points of
diversion of waters for irrigation,” but omitted any reference
to the Lake. United States v. Walker River Irr. Dist., 11 F.
Supp. 158, 162 (D. Nev. 1935). They also point to statements
made by counsel in the 1930s, in which they mentioned the
Basin, but not the Lake. We give little weight to these
anecdotal statements. The Decree’s export restriction is not
structured as an inclusionary list of those places to which
water may be sent. That Walker Lake itself—an obvious and
dominant physical feature in the Basin—was not mentioned
by the court or counsel means little in light of the Decree’s
text and purpose. The Commissioners’ interpretation flies in
the face of history and logic and that ancient and simple
maxim aqua currit et debet currere ut currere solebat ex jure
naturae: water runs and ought to run as it is accustomed to
run, according to the law of nature. Wholey v. Caldwell,
41 P. 31, 32 (Cal. 1895); Lux v. Haggin, 4 P. 919, 920 (Cal.
1884); Lobdell, 2 Nev. at 276. We conclude that Walker
Lake is part of the Walker River Basin. As a consequence,
dedicating water from the Walker River to Walker Lake does
not violate the Decree’s prohibition on delivering water
“outside of the basin of the Walker River.”

                    IV. CONCLUSION

    The judgment of the Decree court is reversed. We vacate
the opinion below and remand with instructions to grant the
Petition to Confirm Nevada State Engineer Ruling No. 6271
of March 20, 2014, grant the Petition to Confirm California
58 NEV. STATE ENG’R V. U.S. BD. OF WATER COMM’RS

State Water Resources Control Board Report of May 29,
2014, and modify the Decree accordingly as necessary.

   REVERSED and REMANDED.
