ECONOMIC IMPLICATIONS OF A DYNAMIC LAND AND WATER Mack

ECONOMIC IMPLICATIONS OF A DYNAMIC LAND AND WATER Mack
ECONOMIC IMPLICATIONS OF A DYNAMIC LAND AND WATER
BASE FOR AGRICULTURE IN CENTRAL ARIZONA
by
Lawrence E
Mack
A Dissertation Submitted to the Faculty of the
DEPARTMENT OF ECONOMICS
In Partial Fulfillment of the Requirements
For the Degree of
DOCTOR OF PHILOSOPHY
In the Graduate College
THE UNIVERSITY OF ARIZONA
1969
THE UNIVERSITY OF ARIZONA
GRADUATE COLLEGE
I hereby recommend that this dissertation prepared under my
direction by Lawrence E. Mnck
entitled Economic Imilications of a D
.11
.(
for Agriculture in Central Arizona
be accepted as fulfilling the dissertation requirement of the
degree of Doctor of Philosophy
Dissertation Director
L
After inspection of the final copy of the dissertation, the
following members of the Final Examination Committee concur in
its approval and recommend its acceptance:*
J
y
/
/
J
S,,
/h7
21 /
This approval and acceptance is contingent on the candidate's
adequate performance and defense of this dissertation at the
The inclusion of this sheet bound into
final oral examination.
the library copy of the dissertation is evidence of satisfactory
performance at the final examination.
STATEMENT BY AUTHOR
This
requirements
is deposited
rowers under
dissertation has been submitted in partial fulfillment of
for an advanced degree at The University of Arizona and
in the University Library to be made available to borrules of the Library.
Brief quotations from this dissertation are allowable without
special permission, provided that accurate acknowledgment of source
is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by
the head of the major department or the Dean of the Graduate College
when in his judgment the proposed use of the material is in the inIn all other instances, however, permission
terests of scholarship.
must be obtained from the author.
SIGNED:
PREFACE
The research reported in this dissertation focuses on the changes
and adjustments that will occur in irrigated agriculture in two irrigation
districts located in central Arizona.
It is part of a comprehensive study
of the use of Arizona's water resources entitled "Water in Relation to
Social and Economic Growth in an Arid Environmentt' and has been supported
by a grant from The Rockefeller Foundation.
This comprehensive study has proceeded in two parts.
The first
part has been the construction of an interindustry model of the state's
economy with primary importance being placed on the heavy water-using
A second phase, of which the present study is a part, has been
sectors.
a determination of how the output of the agricultural sector will change
in response to various water conditions expected to occur over time in
different subregions of the state.
An integration of these regional
studies of the agriculture sector with other sectors of the economy will
provide a total picture of how the economy of the state will be affected
by changing water conditions.
Intra--sector adjustments in agricultural related industries
following adjustments within the agriculture sector will be determinable.
The social and economic changes necessary to facilitate orderly planning
for changes that will occur in all sectors of the state's economy will
be possible.
Projections of intra-sector and intersector, as well as
total state economic activity, will be possible at the culmination of this
research.
iii
ACKNOWLEDGMENTS
A sincere debt of gratitude is extended to Dr. N. M. Kelso,
who provided constant counsel and guidance at all stages of the author's
graduate studies.
His thoughtful judgments and enduring patience during
the preparation of this dissertation are beyond recompense.
The helpful advice and criticisms of Drs. Robert C. Angus,
William E. Martin, Philip G. Hudson and Robert A. Marshall in the final
preparation of this dissertation are gratefully acknowledged.
The valuable programming assistance provided by Mr. Russell Gum
has been much appreciated.
Fellow students, Drs. Douglas N. Jones and
Harold M. Stults and Mr. Kenneth J. Hock, have also contributed greatly
by providing technical assistance and participating in informal digcussion sessions.
A final note of thanks is due The Rockefeller Foundation and
The University of Arizona, whose generous financial support made this
dissertation possible.
To all of the above who have given so unselfishly of their
time and talents, I extend a personal thank you.
iv
TABLE OF CONTENTS
Fag e
viii
LIST OF TABLES
Xi
LIST OF ILLUSTRATIONS
xii
ABSTRACT
CHAPTER
INTRODUCTION
1
3
Problem Orientation
Geographical Location
Water Sources and -Rights
Land Availability and Use
3
5
6
6
Objectives
Method of Analysis
Assumptions
Data Sources
Review of Related Studies
INSTITUTIONAL FRAMEWORK OF WATER SUPPLY ORCAIIIZATIONS
Central Arizona Water Industry
9
10
11
13
.
16
17
17
Development
Description
Distinctive Features
18
20
22
Users' Cooperative
23
Water Pricing
Water Supply Organizations
Salt River Project
Roosevelt Water Conservation District
Significance of Water Supply Organizations for the
Present Study
REPRESENTATIVE MODEL SPECIFICATIONS
Sample Characteristics
Definition of Size Categories
V
25
25
29
30
31
33
33
vi
TABLE OF CONTENTS--Continued
Page
Production Resources
Land
Irrigation Facilities
Buildings
Water Availability
Machinery Inventory
Custom Operations
Labor
Capital
Management
Alternative Enterprise Combinations
Calendars of Operations and Budgets
Costs and Returns
Yields, Product Prices and Gross Returns
Net Returns Over Variable Costs
Fixed Costs
34
35
35
36
37
38
39
39
40
40
41
41
43
43
47
50
THE LINEAR PROGRME'4ING MODEL
54
Procedural Technique
Components of the Models
54
58
The Objective Functions
Real Activities
Restrictions
Variations in Water Quantity
Variations in Land and Water Availability
Over Time
Land Availability
Groundwater Table Projections
Pumping Costs
Water Supply Functions
RESULTS AND CONCLUSIONS
Projected Adjustments to Resource Changes
Enterprise Combinations
Cropland and Water Use
Net Revenue Changes
Firm Numbers
Allotments
58
58
59
62
63
63
65
69
75
77
77
78
92
96
100
106
vii
TABLE OF CONTENTS--Continued
Page
Total Costs and Net Returns per Farm
Agricultural Demand for Irrigation Water
Water Parameter Variations
Additional Water Sources
Values and Quantities of Additional Water
VI.
SUMMARY AND EVALUATION
LIST OF REFERENCES
107
108
119
119
121
129
133
LIST OF TABLES
Page
Table
Salt River Project Land Use, 1962-1968
7
Roosevelt Water Conservation District Land Use,
1963-4968
8
Selected Central Arizona Irrigation District Data
19
Range of Cropland Acreage, Total Number of Farms,
Aggregate Cropland Acreage, and Number of Farms in
Sample, SRP, 1964
33
Range of Cropland Acreage, Total Number of Farms,
Aggregate Cropland Acreage, and Number of Farms in
Sample, RWCD, 1964
33
Salt River Project Farm Model Sizes
34
Roosevelt Water Conservation District Farm Model Sizes
34
.
Irrigation Well and Ditch Inventory and Investment for
Typical Farm Models, SRP and RWCD
36
Alternative Crop Enterprises Available to Typical Farm
Models, SRP and RWCD
42
Yields, Prices, and Gross Returns per Acre from Field
Crops, SRP and RWCD
44
Farm Model Gross Returns, Total Variable Operating Costs,
and Net Returns per Acre, SRP and RWCD
48
Annual Fixed Costs for Typical Farm Models, SRP and RWCD
51
.
Aggregate Water Availability and Cost by Size Group,
SRP, 1967
Constraints for Aggregate Model Farms, SRP and RWCD, 1967.
16.
.
60
Aggregate Water Quantity Variations in One-Half Acre-Foot
Increments from Zero to Six and One-Half Acre-Feet per
Acre, SRP and RWCD
64
Projected Agricultural Land and Irrigation Water
Availability over Time, 1967-2020, SRP
66
ix
LIST OF TABLES--Continued
Page
Table
31.
Estimated Pumping Lifts and Rates of Groundwater Decline,
1967-2020, SRP and RWCD
71
Pumping Lifts and Pump Water Costs per Acre-Foot for
Selected Years, SRP and RWCD
73
Projected Adjustments on Farms in Size Group I to Changing
Land and Water Availability, SRP
79
Projected Adjustments on Farms in Size Group II to
Changing Land and Water Availability, SRP
80
Projected Adjustments on Farms in Size Group III to
Changing Land and Water Availability, SRP
81
Projected Adjustments on Farms in Size Groups IV to
Changing Land and Water Availability, SRP
82
Projected Adjustments on Farms in Size Group I to
Increasing Water Costs, RWCD
83
Projected Adjustments on Farms in Size Group II to
Increasing Water Costs, RWCD
84
Projected Adjustments in Agriculture to Changing Land
and Water Availability, SRP
89
Projected Adjustments in Agriculture to Increasing
Water Costs, RWCD
90
Projected Adjustments in Agriculture to Changing Land and
Water Availability and Increasing Water Costs, SRP and RWCD.
93
Projected Water Use by District, per Acre by District
and by Study Area
97
Projected Aggregate Net Revenue over Variable Production
Costs by Farm Size Group, Irrigation District and
Study Area
98
Projected Change in Farm Numbers by Farm Size Group, SRP,
1967 and 2020
103
Gross Returns, Fixed Costs and Net Revenue per Farm
and Its Allocation, 1967
105
x
LIST OF TABLES--Continued
Page
Table
Demand for Irrigation Water at Various Prices by all
Farms in Each Farm Size Group and by the Aggregate of
all Farms, SRP, 1967
114
Demand for Irrigation Water at Various Prices by all
Farms in Each Farm Size Group and by the Aggregate of
all Farms, RWCD, 1967
115
Estimated Time-Related Demand for Replacement Water for
Agriculture in the SRP and RWCD
122
Projected Net Revenue at Selected Marginal Water
Prices, SRP and RWCD
125
Projected Net Revenue per Acre, Water Use per Acre,
and Net Revenue per Acre-Foot of Water Used, SRP and RWCD.
.
130
LIST OF ILLUSTRATIONS
Page
Figure
Central Arizona Groundwater Subareas as Determined by
United States Geological Survey
Depth to Water, 1967, and Change in Water Level, 1962-1967,
in Selected Wells in the Central Part of Arizona
4
70
Projected Water Use and Net Revenues over Variable
Production Costs, SRP
101
Projected Water Use and Net Revenues over Variable
Production Costs, RWCD
102
Individual Model Farm Demands for Irrigation Water,
SRP, 1967
109
Individual Model Farm Demands for Irrigation Water,
RWCD, 1967
110
Aggregate Agricultural Demand for and Supply of
Irrigation Water, all Farms, SRP, 1967
112
Aggregate Agricultural Demand for and Supply of
Irrigation Water, all Farms, RWCD, l97
113
xi
ABSTRACT
Irrigated agriculture's future in central Arizona is dependent
upon the availability of two relatively fixed and limited resources:
land and water.
Adjustments within the agricultural sector will flow
directly from, or in response to, changes in the availability and/or
costs of these production factors.
This study explores the agricultural use of these two factors
of production and adjustments that will follow from their changing
availability and cost over a 53-year period from 1967 to 2020.
The area
of central Arizona under study encompasses two irrigation districts-the Salt River Project (SRP) and the Roosevelt Water Conservation
District (RWCD).
A structural model of the agricultural sector was synthesized
from a survey of 102 operating farms in the study area.
Models of four
farm sizes were employed in a linear programming analysis to depict
economies of scale.
All four models were used to represent SRP farms,
while two were used to represent RWCD farms.
These farm models were held
constant throughout the projection period, except for specified changes
in the number of acres represented by each model (a decrease in land
availability) in the SRP and the increasing water cost with which they
are confronted in the RWCD.
All other changes and/or adjustments wIthin
agriculture are, in this analysis, dependent upon these land availability
and water cost factors.
xii
xiii
Agricultural land and irrigation district surface and groundwater
availability are considered factors exogenous to the agricultural sector.
In the SRP, land and its appurtenant water rights have been and will continue over the projection period to flow into the urban-industrial sector
at the expense of the agricultural sector.
The cost of obtaining ground-
water will increase over the projection period as the groundwater table
declines.
This increasing cost of groundwater will affect adjustments in
agriculture in the SRP only slightly since water is provided to agriculture
primarily through a user's cooperative which has excess electrical power
revenues available to subsidize water prices to farmers.
Increasing water costs in the RWCD will have a considerable
affect on adjustments in agriculture because of the absence of revenue
from any source to subsidize the cost of obtaining groundwater.
Land
availability is assumed constant in this district and, therefore, is of
no significance in adjustments that occur over the projection period.
Acreages of crops producing high values per acre-foot of water
used are not affected by projected decreases in cropland and/or increases
in water costs.
Adjustments occurring within agriculture over the pro-
jection period take place in the acreages of those crops which produce
a low net return per acre-foot of water used.
As land availability decreases and/or water costs increase over
the projection period, cropped acreage, total water use,
over variable production costs decline.
and net revenue
The changes are not proportional
since adjustments take place in the acreage of those crops which produce
low values per acre and per acre-foot of water used.
In the SRP, cropped
acreage is projected to decrease 76 percent, total water use to decrease
xiv
71 percent, and net revenue over variable production costs to fall
approximately 50 percent due largely to continuous transfer of land and
water out of agriculture.
Projected declines in cropped acreage in the
RWCD are 50 percent, total water use decreases 45 percent and net revenue
over variable production costs falls 21 percent due entirely to increasing
cost of water.
A second phase of this analysis presents a demand function for
irrigation water in each district over price ranges from zero dollars
per acre-foot to those at which no water would be demanded.
In the SRP,
positive price and quantity relationships were found to exist from a
price of $248 per acre-foot at which quantity would be zero, to a quantity
of 816,873 acre-feet demanded at a zero price.
Price and quantity
relationships in the RWCD ranged from zero quantity demanded at a price
of $113.36 per acre-foot to a quantity of 130,338 acre-feet at a zero
price.
A final section of this study treats various possible sources,
uses, and values of additional water to agriculture in each irrigation
district over the projection period.
CHAPTER I
INTRODUCTION
Economic activity in Arizona is heavily dependent on an annually recurring quantity of surface water and a fixed stock of groundwater.
The groundwater is being depleted at a relatively rapid rate.
Competition among present and potential uses and users for this water
supply and for the land area on which it may be used occurs in all parts
of the state, though most acutely in areas of intensive irrigation and
rapid urbanization.
The intensity of this competition is expected to
become more acute as the groundwater table falls, population increases,
and the nonagricultural economy grows.
These changes have been occurring
at relatively rapid rates during the past two decades and are expected
to continue.
In order better to understand the implications of this intensifying competition for limited water supplies, the Department of Agricultural Economics, in cooperation with other segmeiits of The University of
Arizona, has initiated studies that examine its implications for the
continued growth of the Arizona economy, assess the need for changes in
the state's water policies, and determine the economic benefits and
costs of developing additional water supplies.
These studies seek to
determine the historic, present and future water demands in the state.
They also explore the political, economic, legal and sociological implications of past, present and future water use patterns.
1
2
One such study is entitled "Water in Relation to Social and
Economic Growth in an Arid Environment.
The goal of this study is to
determine the aggregate effects on the state's economic output that will
result from possible changes in economic activity in those sectors of
the economy affected directly by growing economic scarcity of water.
To this end, a major phase of this study has been the construction of an
inter-industry "flow-of-funds" model of the Arizona economy (Tijoriwala,
Martin and Bower, 1968).
This model will provide the mechanism for de-
termining by conventional input-output analysis the aggregate economic
effects of individual sector changes induced by growing competition for
land and water.
Since irrigated agriculture is an important sector of
the state's economy and accounts for approximately 90 percent of all
water used in the state, changes that will occur in that sector due to
growing competition for land and water are of primary importance in the
use of this model.
Aggregate water use in the state's agriculture may change over
time because of water's increasing economic scarcity and changing land
availability.
As water costs increase and land availability declines,
gross and net revenue and land and water use in agriculture will decline.
These changes and adjustments will have direct and indirect effects in
other sectors of the economy.
These intersector effects stemming from
changes within the agricultural sector will be determined via the
input-output model described above.
This research is supported by a grant from The Rockefeller
1.
Foundation and is being conducted under the direction of Dr. M. N. Kelso,
Professor of Agricultural Economics, Agricultural Economics Department,
The University of Arizona, Tucson.
3
The research reported in this dissertation focuses on the changes
and adjustments that will occur in irrigated agriculture in two irrigation
districts located in Maricopa County in central Arizona.
In this area,
there is competition for both land and water between the urban-industrial
and agricultural sectors.
The adjustments and changes in the agricultural
sector herein determined, together with those determined by Stults (1968),
Jones (1968) and Hock (n.d.) and others for other irrigated areas, will
be used in the input-output model of the state's economy to project
aggregate state changes in economic activity as the water and land base
change.
Problem Orientation
Principal characteristics of the area relevant to the problem
under investigation are described below.
Geographical Location
The area with which this study is concerned is composed of two
separate, but related, irrigation districts (see Figure 1, Page 4).
These are the Salt River Project (hereafter denoted by the initials
SRP) and the Roosevelt Water Conservation District (hereafter denoted
by the initials RWCD).
These irrigation districts are distinct in that
their water supply, its cost, and the availability of agricultural land
differ and this difference is expected to increase.
Their similarities,
which provide a basis for studying them together, are their location in
a singular climatic region, their access to common basic resources, and
their production of identical combinations of crops with similar production techniques and resource organization.
Source:
Figure 1.
r
A
1s: CANOLE
N
AREA
6.2 L
Vt 3E.
COUSTYI
R.4E.
RIVAL
IMARICIPA CSTY
r
I
(I
- '-
_
O]h
QUEEN
-
CREEX-
--
Junct.On
SO PC NO
I
1t5 E.
I
P.6 C.
lION
U
UU
!AUlUUUUI
-
IkUUUUUU
h.
ruurdiIIIIUUiU
U 'dUU
AN TAN U
j4
El
i*iri
1UiUJI
UUUUW4ULIIUUU
I1I
.-J__ -' ..i....
-
R.9E.
iIiIU
' IIi!ç!Jlihl
UU
y
ChUndI.n
C A-
' ua
tuiuiUa
.UII
J
UlU .t1idncnU
IY
mI
1lU4UI
if
I)
RE.
Central Arizona Groundwater Subareas as Determined by United States Geological Survey.
R. I E.
--
-t
ttr
L, r4
I.
"
Ui1U'
U...
In
UUUUUUIIIIUI$EIUIII1
lit
, u.I.UU.t..CrPiU.UU!.iU!
NIUUUliUUULRW'p
UI1
WU*UUU51
Pu
UUI,
S..
ii,1Nv
iiuui;aui
uiuiiu.
'--I
ii
Glenda
White, Stulik and Rauh, 1964.
60/HOARY OP SUBAREA
IRRIGATION CVAL
(20-/Had iaHHn.H/)
CHANGE IN WATER LEVEL
---20
RAND-ROCK AREA
ALLUVIAL AREA
NIX-
TOLL E SON-
uuu.
P_lw.
EXPLANATION
dui.
4.1..
-.
PUU
PHOE
---- _l_
luU4 UIkIll .P,
_UlU.lIUIuI.UU..
UUURViUi
Iu. ' I.
Prii
5
Annual rainfall is 10 inches or less and is of minor consequence
in agricultural production,
Soils are generally of sufficient depth to
provide excellent growing conditions.
Soil compaction and waterlogging
are minor problems that have, from time to time, presented problems but
are presently of little consequence.
Drainage wells have been drilled
to alleviate shallow water tables in the past, but at present are more
detrimental than helpful.
Cropping patterns in both districts are diversified.
Major field
crops include cotton, alfalfa, small grains and a variety of vegetables,
of which lettuce is predominant.
Cilrus, together with other speciality
crops, is of minor importance so far as land and water are concerned.
Water Sources and Rights
Irrigation water is obtained from three sources in both districts.
These are surface-water runoffs carried in the Salt and Verde Rivers,
project pumps, and private pumps.
Surface water is obtained exclusively
from four reservoirs on the Salt River and from two reservoirs on the
Verde River, constructed for and operated by the SRP.
These reservoirs
capture and retain runoff from approximately 13,000 square mules of
watershed located in east central Arizona.
This water is distributed
to SRP and RWCD lands under a variety of water rights based upon past
history of water use, continuous cultivation, contractual arrangements,
and water availability.
In addition to surface water, both districts produce water from
pumps which they operate on a cooperative basis with district members.
The SRP and RWCD operate 250 wells and 60 wells, respectively.
6
A third source of irrigation water is wells owned and operated
by private landowners in the districts.
The exact number of these
private wells is not known; however, estimates place approximately 500
in the SRP and 26 in the RWCD.
Both the SRP and RWCD have been declared
critical groundwater areas by the Arizona State Land Department.
As a
result, only replacement irrigation wells may be drilled (Ernst, 1954).
No restrictions are placed on the quantities of water that may be produced from existing wells or their replacements.
Mann (1963), in
Chapters 3 and 4, describes the surface-water and groundwater law under
which these districts operate and the history of its development.
Land Availability and Use
SRP land use is presented in Table 1.
pattern is evident.
The changing land use
Irrigated agriculture has experienced a decline in
land availability coincidental to an increase in residential and industrial land use.
Since water rights are attached to land, this means that
as land moves from one use to another the water also moves.
This movement
of land and water is expected to continue.
Land use data for the RWCD are presented in Table 2.
lands are used exclusively for agricultural purposes.
not shown, is in subdivision use.
Project
A small portion,
The area subdivided occupies only
about one-tenth of one percent of the total acreage in the district and
has not exhibited any recent tendency to change.
Obj ectives
A first objective of this study is to determine the marginal
value productivity of irrigation water in the SRP and RWCD as increasing
Source:
1968b
Salt River Project, 1962-l968.
Preliminary spring report, compiled in June, 1968.
b.
135,742
Totals are not constant because of reporting procedures.
13,027
a.
148,769
9,438
80,045
238,252
238,252
77,051
9,672
135,600
15,929
151,529
1967
238,252
75,559
9,762
135,890
17,041
152,931
1966
238,252
72,971
9,917
145,329
10,035
155,364
1965
238,252
70,170
10,085
146,031
11,966
157,997
1964
238,081
68,000
12,030
159,881
1963
10,200
146,289
19,289
165,575
147,851
Totala
239,150
Subdivided
62,000
(Acres)
Farmsteads, Ditches
and Roads
10,575
Salt River Project Land Use, 1962-1968.
Area
Area in
Fallow
Irrigated
or Idle
Cultivation
1962
Year
Table 1.
a.
39,415
2,545
1,056
Source:
Roosevelt Water Conservation District, 1963-1968a.
Totals may not be exact due to rounding procedures.
5,544
30,310
1968
39,415
2,568
902
9,823
5,968
26,227
29,977
1967
39,425
2,500
956
12,031
9,425
23,882
26,544
1966
39,425
2,445
730
9,223
5,510
26,912
30,740
1965
39,425
2,536
730
7,105
4,117
28,786
32,042
1964
39,425
2,415
678
27,803
31,453
8,358
Totala
Uncleared
4,876
Roosevelt Water Conservation District Land Use, 1963-1968.
Fallow or
Area in
Farmsteads,
Idle
Cultivation
Fall
Ditches and Roads
Fall
Spring
Spring
1963
Year
Table 2.
9
quantities are applied to cropped acres.
Production theory states that
as larger amounts of water are applied to these acres, its marginal
value productivity will fall since each additional quantity is employed
in the production of crops, or units of crop output, from which declining
amounts of net revenue are received per unit of additional water used.
These successive and declining marginal value products from increasing
quantities of water applied constitute the demand function for water in
irrigated agriculture in these districts as of 1967.
The second and primary objective is to project changes in crop
enterprises, in volume of crop output, in net incomes, and in water use
that will occur in irrigated agriculture in the districts as the availability of their land and water bases changes over time.
The adjustments
and changes are projected for each district, starting in 1967 and proceeding by five-year intervals from 1970 to 2020.
Method of Analysis
Linear programming is the analytical tool used to develop the
demand function for water and to predict changes in the agriculture of
the districts that will follow from changes in the agricultural land and
water base over time.2
Basic inputs for the linear programming models
were determined from a field survey.
This survey provided the necessary
data for a description of the typical agricultural resource organizations,
The program employed is Aiphac, Version I, developed by
2.
Thomas Zierer at the University of California, Berkeley, for use on the
6400 Control Data Computer.
10
cropping patterns, size distribution of farm units, and operation procedures for producing an array of relevant crops.
From these data,
calendars of operation and technical and financial budgets based on
available production equipment were constructed for each of four distinct
farm sizes found to characterize the area.
Linear programming models
were then developed for each of four farm sizes.
All four models were
found to be relevant in the SRP, while but two were needed to represent
the resource combinations and production techniques in the RWCD.
These
six linear programming models, which represent typical operating units
in the two districts, are representative of all farming units in the study
area.
Once constructed, the linear programming models were used to
generate an aggregate demand function for irrigation water in each
district and to project adjustments in agriculture to a changing land
and water base over time.
As sumptions
The method of analysis described above include severalassumptions
basic to any linear programming problem and some that are necessary to
this particular study for purposes of workability.
Those that are
inherent in the analytical tool are well documented in readily available
literature.
Assumptions employed to provide workability in this study
are recognized to be departures from real world conditions, but are
necessary in order to focus attention sharply only on the consequences
of land and water changes.
This sharpness of focus was obtained by
arbitrarily holding constant in the analysis other real world variables
not germane
to this objective.
11
The overriding economic assumption is that the elasticity of
supply and demand will remain unchanged.
That is, the ratio of product
prices to factor costs, and among product prices and factor costs,
will not change over the projection period.
It is further assumed that technical production coefficients
will not change over time; that the assumed enterprise mix will not
change in favor of new varieties of existing crops or totally new crops
requiring substantially different resources; that the quality of irrigation water will remain such that the quantity needed on any specific
crop will remain constant or that costly materials or practices will not
be needed to correct its quality; and that all project lands are, and
will remain, homogeneous in quality.
Current government acreage control policies are also assumed to
continue unchanged from those prevailing currently.
Irrigation district
operations and policies are assumed to continue as they have in the recent
past.
This includes such district-related matters as their size, their
policies relative to water deliveries, their water right structures,
and voter participation in determining policies relative to their operation.
Data Sources
Input-output coefficients were developed from information
ob-
tained from a sample of operating units in the two irrigation districts.
The basic population list from which the sample was drawn was obtained
from the list of farms with cotton allotments maintained by the Maricopa
County Agricultural Stabilization and Conservation Service (ASCS).
list contained information as to both total farm acreage and cotton
This
12
allotment acreage for each farm.
The list was found to be quite com-
plete as almost all farms in the area grow cotton.
Farm units of less
than 30 acres were excluded from the population on the assumption that
they were not commercial farms.
A commercial farm was defined as one producing $10,000 or more
in gross revenue.
The ASCS farm list was correlated with the United
States Census of Agriculture 1959 (United States Bureau of the Census,
1961) as a check on the number and distribution of farms by size.
population of farms was arrayed by sizes from 30 to 5,000 acres.
The
Sampling
ratios were determined, both on the basis of concentration of numbers of
farm units within ranges and total farm acreages.
This method thus con-
sidered both number of farms and total acreage in farm units by size
classes.
It also provided a basis for sampling operating units as well
as acreage, in that smaller farms were sampled more heavily in terms
of number of units while larger farms were sampled more heavily in terms
of total acreage.
A sample was drawn from the population by a systematic
procedure involving a random start within the array of farms in each
size range
A farm survey questionnaire (Mack, 1968) was developed, of which
102 were completed in the study area.
Ninety were from the approximately
150,000 acres of irrigated land in the SRP, and 12 were located in the
32,000 acres of irrigated cropland in the RWCD.
Retail suppliers were contacted to obtain factors costs.
Maricopa
County Extension personnel extended considerable advice as to agronomic
practices in the area.
Much of the basic data relative to product prices,
machine accomplishment rates, and variable operating costs are presented
13
by Young, Martin and Shaw (1968).
Individual crop calendars of operations
and budgets can be found in an unpublished file report of the Department
of Agricultural Economics (Mack, 1968).
Review of Related Studies
Several studies have been carried out over the past 10 years
that treat, in part, the particular problem investigated here.
Several
other works deal with a similar problem in its entirety in other areas
of Arizona.
However, this study is unique in that it analyzes resource
use within the agricultural sector while considering urban-industrial
changes only as exogenous factors.
The Planning and Zoning Departments of Maricopa County and the
City of Phoenix (City of Phoenix and Maricopa County, l959a and 1959b)
have undertaken a number of studies for purposes of long-range planning.
These studies deal with an array of factors such as present population
characteristics and projections, employment and income characteristics,
future employment needs, present land and water need and use and their
probable need and use in the future.
They consider the agricultural
sector only in its role as a user of resources in the total economy.
They make no analysis of the use of resources within agriculture.
They
take present resource use within agriculture as given and project
proportional adjustments in agricultural sectors solely on the basis of
urban population increases and their needs.
Western Business Consultants, Inc. (1959) and Western Management
Consultants, Inc. (1965) have prepared studies that analyze present
resource use and provide future expected patterns of change.
These studies
emphasize resource use and expected use in all sectors of the county's
14
economy but, similar to the above studies, do not treat within-sector
use.
They do, however, provide an inventory of resource need and avail-
ability outside the agricultural sector.
Dr. Heinrich J. Thiele (1965) conducted a study which centers on
water use and its potential availability in the Phoenix Metropolitan
Area.
This area encompasses the study area of the SRP and RWCD.
analysis relates water need to its availability.
Thiele's
He assumes a constant
per acre use of water in the agricultural sector in his predictions of
water use by the several sectors that compose the Phoenix Metropolitan
Area.
Smith (1968), in a sociological study of the SRP, describes many
of the attitudes of project personnel and water and power users.
He
focuses on the effect of different degrees of disorganization, secular-
ization and individualization with respect to changes in the distribution
of water and increasing number of participants.
SRP actions and their
accompanying user reactions are described and assessed.
Future courses
of project action are predicted on the basis of these assessments.
Smith's analysis provides a great deal of information upon which the
project's future relations with its agricultural participants can be
based.
His work is relied upon and cited extensively throughout this
study.
Hedges and Moore (1962-1965) have completed studies in the
San Joaquin Valley of California, analyzing adjustments that occur in
response to changing irrigation water availability and costs.
The
initial features and methods used by Hedges and Moore are similar to
15
those of the present work.
This study, however, employs a dynamic
analysis whereby adjustments within agriculture are related to a changing
land and water base.
CHAPTER II
INSTITUTIONAL FRAMEWORK OF WATER
SUPPLY ORGANIZATIONS
Institutional arrangements develop out of some group need for
the fulfillment of a specific function.
Rules are established to pro-
vide guidelines or bounds within which orderly actions on the part of
members of the group can proceed to satisfy their own individual needs.
These rules provide the structure or framework of the institution.
institutional framework develops.
Hence,
This framework may be broad and quite
loosely constructed or it may be narrow and very rigid.
supported by custom or a formal legal structure.
It may be
Individuals or organ-
izations may operate within institutional frameworks.
Water supply organizations conform to the pattern of development
described above.
These organizations perform the function of developing
and/or delivering water to users under the auspices of a set of welldefined regulations.
They have evolved from rather loosely formed
groups of individuals fulfilling the needs of a small number of users
to highly developed formal organizations which function within a rigid
legalistic framework.
In many instances, they have adapted themselves
to performing an array of functions that members desire.
has changed or been extended.
The framework
New legislation has preceded as well as
followed these changes.
16
17
Central Arizona Water Industry
Water supplies in central Arizona have been developed by a large
number of organizations which can be nominally lumped together as an
industry on the basis of their generally similar economic functions.
This industry has evolved to become one of the most important and powerful
in central Arizona.
As such, its influence is felt throughout the entire
economy of the area.
A study of any sector of the economy that uses large quantities
of water supplied by the water industry necessarily involves some development of the water industry itself.
A synopsis of the industry includes
such factors as its development, physical features, and number of operating
units.
Development
The first modern irrigated agriculture in central Arizona began
in about the year 1869 when only a few hundred acres were under cultivation.
The first irrigation facilities were owned and operated by
private companies that supplied water directly from the surface sources
to the land.
In 1910, approximately 151,000 acres were being actively
farmed under irrigation.
Since that time, the number of acres of irri-
gated cropland in this area has increased with some fluctuations and
is presently of the approximate magnitude of 510,000 acres.
During this
60-year period, several irrigation districts have been established.
These date from 1903 to 1964.
and surface water.
Several districts distribute both pump
Some districts supply their members with only pump
water, while others function only as ready-made organizations through
18
which supplies of surface water might be distributed if it should
become available.
Description
Surface water supplies for central Arizona are obtained almost
exclusively from the Salt and Verde Rivers.
A series of six dams impound
water for controlled use by the agencies that exercise a claim on this
surface water.
This water, or its equivalent in SRP pump water, is
delivered through the conveyance system of the SRP, which uses the
largest quantity, to the lands of the Fort McDowell, Gila and Salt River
Indians and to the RWCD, St. Johns Irrigation District, Buckeye Irrigation
District, and the Peninsular-Horowitz Ditch Company.
The City of Phoenix
receives "gate" water from Horseshoe Dam on the Verde River.
This claim
arose when the City of Phoenix financed the construction of higher "gates"
on Horseshoe Dam, thus increasing its potential reservoir capacity.
The
only other source of district surface water is Lake Pleasant on the
Agua Fria River, which provides a small, rather unstable quantity of
water to the Maricopa County Municipal Water Conservation District.
In addition to project pump and surface -iater, private pumps
also operate in most districts.
The number of and quantity of water
obtained from these wells vary considerably among districts.
In several
districts, private pumps provide the one single source of water.
Table 3
summarizes selected central Arizona irrigation district data.
Cities and towns also operate and maintain pumping units in
central Arizona.
The cities of Phoenix, Mesa and Tempe are the three
largest municipal water users in this area.
population centers.
They are also the major
The cities of Phoenix, Tempe, Gilbert, Glendale
1
X
X
X
X
X
X
X
X
X
X
X
X
X
x
x
Inactive
United States Department of the Interior, 1965.
NcMicken Irrigation District
New State Irrigation and
Drainage District
Peninsula Ditch Company
Roosevelt Irrigation District
Roosevelt Water Conservation
District
Salt River Indian Irrigation
Project
Salt River Project
St. Johns Irrigation District
Queen Creek Irrigation
District
No.
Aquila Irrigation District
Arlington Canal Company
Buckeye Water Conservation
and Drainage District
Chandler Heights Citrus
Irrigation Districts
Harquahala Valley
Irrigation District
Maricopa County Municipal
Water Conservation District
Source:
13.
14.
15.
12.
11.
10.
9.
8.
7.
6.
5.
4.
3.
2.
1.
Active
x
Power
Generation
Selected Central Arizona Irrigation District Data.
Irrigation District
Table 3.
x
X
X
X
X
X
X
X
X
x
X
X
X
X
X
Project Sources
Ground- Surface
Water
Water
46,619
240,000
2,960
9,600
X
39,425
2,400
2,262
38,152
35,000
45,000
60,000
X
X
X
X
X
X
X
X
X
1,380
20,465
42,240
4,800
X
X
X
Acreage
Private
Pumps
20
and Peoria have domestic water contracts with the SRP.
Water delivered
under these contracts may be from surface or ground sources.
Several
other smaller municipalities are located in the area but their combined
total water use is less than five percent of the total municipal use
(Arizona Interstate Stream Commission, 1967:36).
Distinctive Features
Basic similarities exist between the water industry of central
Arizona and other industries.
In spite of these basic similarities,
there are also fundamental dissimilarities between the conventional
industry of privately owned, profit-seeking firms and a water industry
like that of central Arizona.
Due to these distinct features of the
water industry, its conduct differs from that of conventional industries.
Bain, Caves and Margolis (1966), in a study of the northern
California water industry, have presented six major ways in which the
water industry differs from a privately owned, profit-seeking industry.
These also apply to the industry in central Arizona.
First, the rela-
tionship between water suppliers and users is typically geared to the
provision of maximum advantage to the user of water rather than to its
supplier; second, regulations on the actions of the public utilities
operate to restrict districts in the water industry; third, there is
competition among distributing agencies for supplies of water rather
than for customers; fourth, there is generally an allocation of some
water to benefit the public generally rather than special groups of
direct users; fifth, there is an inflexibility of long-term allocations
of water supplies and a resulting imperfection of the competitive process
in meeting changing patterns of demand for water; and sixth, there exist
21
legal barriers to the bargaining processes as substitutes for competitive
markets in allocating water and water rights.
Markets in the water industry are not continuous in either space
or time.
Generally, competition exists only for long-term or perpetual
legal rights to surface flows or groundwater, rather than water supplies
on a day-to-day or year-to-year basis.
The result of this nonexistence
of continuous competition is that rigid and inflexible allocations of
water rights are established among different users.
established, become effectively perpetual in law.
These rights, once
The legal processes
then operate as substitutes for markets in determining the allocation
of water and water rights among competing users.
In the water industry, there is no live and continuing compet-
itive process through which water supplies may be reallocated due to
changes in technology or patterns of demand for water.
As stated by
Bain, etal., (1966:10), "It is rather an episodic historical process
reflected in a series of events, each dated in time."
In a conventional private industry independent sellers and
buyers are said to be "at arm's length" from one another.
Members of
the industry produce in order to sell to others at a profit rather than
to use themselves what they produce.
Conflicting aims exist between
buyers and sellers in that the seller seeks to sell at as high a price
as possible while the buyer desires to buy at as low a price as possible.
The typical case in the water industry, however, is one on which the
aims of both the "sellers" and "buyers" have a common goal:
to provide
water to its users (buyers) at as low a price as possible, and in the
quantities and at the times desired.
This is accomplished either through
22
a self-supplying user of water or a water supply organization which acts
as a users' cooperative in developing and supplying water for its members
as the water users.
Users' Cooperative
A user-supplier of water combines the function of developing
water and using it into a single function.
exists.
No supplier-user relationship
This is typically the case of a farmer operating his own wells.
His motive is to produce water in a quantity and at a cost such that
his profit from his water using activity will be maximized.
The farmer's
water producing activity and his water using activity are combined into
a single entity under one management head.
An irrigation district operating as a users' cooperative for a
particular group is not an independent entity.
It is not completely
separated from the user's in that it does not have the conventional arm's
length relationship of seller to buyer.
It is rather "an instrumentality
created by a group of users to act in ways most advantageous to them"
(Bain, etal., 1966:9).
Its motive is not to make a profit but to pro-
vide water in such quantities and at a cost that will permit its organizers to maximize their individual profits from the productive activities
in which they use water.
The relationship that exists between the dis-
trict and its members is a seller-buyer one in that the users have control
over the administration of the actions and charges of the district supplier.
From this it follows that the users' cooperative can be thought of as
vertically integrated with the operations of the individual members.
vertically integrated firm is interested in maximizing the profits for
the whole chain of operations.
The cooperative will operate to the
The
23
advantage of its members.
Water will be supplied in a mutually agreed
upon quantity to each member at the lowest possible cost.
Individual
member water rights may still be important within the users' cooperative,
but each member will be treated equally after rights extra-legal to the
cooperative have been satisfied.
Several characteristics of the water industry provide an explanation as to why users' cooperatives have developed in this industry.
These
include such things as water law, a lack of active water markets, externality factors, the need for development of organizations which will assure
long-term supplies of water and construction of facilities for which funds
can be obtained by pledging tax yields as security for the repayment of
loans.
Water Pricing
Pricing patterns of agricultural water districts have been built
on the basis of numerous considerations of equity and efficiency as seen
from within each individual district.
Water districts operating in the
agricultural sector as users' cooperatives generally set water prices
and tax rates so that current variable and fixed costs will be covered,
or occasionally to cover these costs, plus a contribution to a "safe"
surplus (Bain, et al., 1966:332).
Water is typically priced by water
districts at its average rather than marginal cost of production.
The
SRP does, however, distinguish between surface water and pump water in
its pricing policy in a manner related marginally to the higher cost of
providing pump water in the aggregate in comparison to the cost of providing surface water also in the aggregate.
Emphasis is placed on
maintaining charges fairly constant (or increasing or decreasing at a
24
constant rate), thus avoiding large fluctuations on a year-to-year basis.
Changes in water prices and taxes come slowly and tend to be small when
they do occur, unless some major reorganization of the district's facilities or size takes place.
The relative pattern of water rates and taxes differs substantially
Those districts in relatively prosperous areas, or
among districts.
districts which obtain large incomes from sales of hydro- or steamgenerated electric power, thus needing only modest water revenues to
cover costs, often use a moderate assessment charge plus a relatively
small per acre-foot water charge.
These districts may supply some
quantity of water at some fixed charge to its members in the form of an
assessment to cover district fixed financial costs.
Surface water may
also be made available to members at no charge when district facilities
are inadequate to store large watershed runoffs at times when district
storage facilities are full.
Districts that depend solely on a relatively
expensive source of water tend to set their assessment prices to cover
their fixed obligations and the maintenance of their system; their irrigation water rates being set somewhere near their variable costs of its
production.
Water allocation on a nonprice basis takes place in some irrigation districts.
-
The types of rationing used depend on the nature of
the district's physical facilities.
Rationing may be in terms of a
quantity per unit of time, a total "seasonal" quantity, or some combination of these.
A "prorate" among member-users may exist due to a
"shortage" of available water during a specific period of time or because
of an inability of the distribution system to adequately satisfy periodic
peak demands.
25
Water Supply Organizations
Two irrigation districts comprise the study area to which this
research is addressed.
They are located adjacent to each other in central
Arizona. The SRP and the RWCD are both organized under Arizona law.
The
SRP is incorporated as a municipality and the RWCD is organized under
Arizona irrigation district statutes.
They are owned and operated by
the land owners within the districts.
Operating decisions are made by
managers appointed by boards of directors.
The directors are elected
from subdivisions of the districts by the members in that district.
The
cooperative form of organization and operation applies
to both of these districts.
Water users in the SRP face a vory favorable
water supply situation, based almost entirely on project developed facilities.
In the RWCD, water supply conditions are less favorable than those
in the SRP, but users generally can obtain project water at lower costs
than if they produce it on an individual basis.
In both projects, water
cannot be transferred outside the districts.
Salt River Project
This project was authorized for construction in 1903 and was the
first project undertaken under the National Reclamation Act of 1902.
The full name of this organization is the Salt River Project Agricultural
Improvement and Power District.
The Salt River Valley Water Users'
Association operates the irrigation system and acts as an agent for the
project.
The project was organized and incorporated under the laws of
the Territory of Arizona in 1903, primarily to establish a central organ-
ization which could represent the individual water users in dealings with
the Secretary of the Interior.
26
In 1949, the Salt River Project Agricultural Improvement and
Power District took over control of the irrigation facilities of the
project, but the Salt River Valley Water Users' Association continues
to operate them.
This was done in order ".
.
to secure for the Salt
River Valley Water Users' Association lands, rights, privileges, exemptions and immunities granted to public corporations or political subdivisions of the State" (U. S. Department of the Interior, 1965).
The service area of this project includes 238,250 acres in
central Maricopa County.
This area surrounds the City of Phoenix, Arizona.
The irrigated
lands lie north and south of the Salt River in the triangles formed by
the intersection of the Salt-Gila Rivers and the Salt-Agua Fria Rivers.
Elevation of the irrigated lands range from 900 to 1,300 feet above sea
level.
At the present time, approximately 80,000 acres of the total area
are devoted to residential, colluLlercial or industrial use.
The transfer
from agricultural to urban-industrial use is expected to continue at a
rate defined in a subsequent section of this study.
Two rivers are the source of surface water.
A series of four
dams and reservoirs on the Salt River and two on the Verde River supply
approximately two-thirds of the present water distributed by the project.
Additional water is obtained from approximately 250 project owned and
operated pumps.
Water is distributed by the project under several
classes and priorities of rights.
Normal flow water rights are those that were established by the
Kent Decree (Hurley vs. Abbott, et al., 1910).
This right related to
water that would be carried by the rivers if their flows were not
27
restricted by dams.
These rights to "natural flows" of the river existed
prior to the development of the project and give their holders first
claim on diversion and use of surface water "flowing" in the river at any
and each point in time.
Lands entitled to this water must have been in
continuous cultivation beginning sometime between 1869 and 1909.
Land
cultivated and irrigated in the earlier years of this time period has a
greater probability of obtaining water under this normal flow right than
lands continuously cultivated toward the end of the period.
This water
is delivered to its claimants on demand through the district's system.
During periods of less than adequate flow, many lands with
Much of
priorities near 1909 do not receive any water under this right.
this water right goes unclaimed because it must be used at the time it
would theoretically flow if not held in reservoirs.
Also, most of the
flow of the rivers takes place in the winter and early spring months
when there is little demand for water.
This normal flow water right is
applicable to 151,083 acres of the 238,252 acres of the project area
(Hurley vs. Abbott, et al., 1910).
Water in the rivers over and above that covered and claimed
under
the normal flow right is stored in the project's system.
called stored and developed water.
It is
Rights to this water are held equally
by all agricultural land having capital stock in the association.
After
payment of an annual assessment, the project typically makes an allocation
of this water on an equal basis among project lands.
In some instances,
excess or floodwater becomes available and is also distributed on an equal
basis.
28
Rights to district-developed pump water are held by district
lands for which they were purchased by district members, beginning in
1948.
This right was purchased from the association in one-half acre-
foot per acre increments up to two acre-feet per acre.
This right, when
purchased, is a permanent right to buy pump water from the district if
and when needed.
These are available for sale by the project for an
indefinite period.
As of 1967, 163,580 acres of project land (or about
70 percent of the eligible acres) had purchased 242,376 acre-feet of this
pump water right.
A final water right is that entitled "townsite rights.t'
These
rights provide for the delivery of water to cities and towns within the
project.
This right is granted under the Reclamation Act of April 16,
1906, allowing the project to deliver water to land designated "Townsite
Lands" by the Secretary of Interior (SRP, 1964).
In addition to, and in conjunction with its irrigation operation,
the SRP maintains and operates an extensive electrical power producing
system.
Generating capacity is composed of both hydro and thermal plants.
These facilities have grown tremendously over the years and revenue
obtained from the electrical plant has been used in support of the water
production and delivery operations.
This financial contribution from
power to water has been increasing over time.
This may be a function of
increasing power revenues, a reflection of increasing costs of water
operations, or both.
29
Roosevelt Water Conservation District
This district covers an area of 39,425 acres in southeast Maricopa
County.
A part of this, 2,544 acres, is owned by the district and water
rights have been withdrawn from it.
All other lands within the district
boundaries have equal rights of access to district water.
The district
water supplies are derived from both surface and underground sources.
The district operates approximately 60 wells from which two-thirds to
three-fourths of its water supply is produced.
Typically, one-quarter
to one-third of its supply is obtained from the Salt and Verde Rivers
and the balance from project wells.
During the late spring and summer
months, the project wells are unable to furnish enough water to meet the
demand of users.
Surface water impounded in the SRP's system, to which
the RWCD has a claim, is then used to help meet these peak demands.
The
source of this water is a 1924 agreement whereby the district contracted
with the SRP to pay the cost of lining certain portions of the SRPts
major canals.
In return, the RWCD was granted the right to use 5.6 per-
cent of SRP diversions for agricultural purposes at Granite Reef diversion
dam.
This water is stored by the SRP and delivered to the RWCD on demand.
In order to apportion the water supply throughout the year and
to insure a more equitable distribution, the district has established a
seasonal "prorate" or limitation on water deliveries to individual disAt the beginning of each year, the board of directors
trict members.
sets the amount of water that will be available to each acre of project
land during the prorate period.
This quantity typically varies between
two and three acre-feet per acre, depending upon the anticipated supply
for the year.
The prorate is generally in effect from early March to
about October 1.
30
Individual members in this district can transfer water rights
from one account to another, either under the same or different ownerships.
Any member having a surplus of prorate allotment water may give or sell
his right to that water to any other member.
The transferred water is
then added to the buyer's account and handled in the same manner as his
original account.
Payments made to the selling member for this water
are in addition to the charge made for the water by the district.
Significance of Water Supply
Organizations for the Present Study
A description of the central Arizona water industry, with special
emphasis on the SRP and RWCD, has been presented in the previous sections
of this chapter.
Water supply organizations play a significant role in determining
the prices, quantities, and delivery circumstances of irrigation water
to individuals, as well as specific groups of users.
The policies of
irrigation water supplying organizations are determined by a majority
of those being supplied within whatever restraints are specified in law.
As such, the water supply organization and the individual firm are integrated through the users' cooperative concept.
An understanding of this
concept and its implications for the individual firm is necessary for the
development of future courses of action on the part of water supply
organizations.
The users' cooperative concept postulates maximum advan-
tage to the water user.
It is assumed in this study that irrigation water
users in the study area will continue to receive this maximum advantage
in the form of a favored position in the structure of water charges.
CHAPTER III
REPRESENTATIVE MODEL SPECIFICATIONS
The synthesis of representative single farm models based on
specified features of a population of farms can be accomplished in a
variety of ways.
Perhaps the most widely used method is through a
sample of that population.
Synthesized representative farm models that specify the struc-
tural characteristics of representative farms of the area provide a means
whereby only the most relevant characteristics of the population of farms
may be considered.
Such models eliminate, or substitute for, the need
to consider each operating unit of the population as a separate entity.
Representative farm models are synthesized from population characteristics
as determined from a survey of farm operating units.
Typical farm characteristics and the models to which they apply,
as determined from the farm survey, are set forth in this chapter.
Model
characteristics are first developed for single representative farm units
within specified farm size categories.
These typical single farm models
are later expanded to cover all farms in each size category in proportion
to their numbers and magnitude in the population of all farms.
When
referring to a size category or group, the term "aggregate" model or group
is employed.
Identification of criteria that are relevant to the attainment
of an objective must relate to those factors that most directly influence
31
32
the variables which relate to the objective.
A concise definition of
these variables is not always possible when the objective is being
formulated.
Pertinent to the objectives of this study, factors that affect
adjustments in agriculture and might be included in farm models suitable
for this study are such things as land, water and capital availability
to farms in the area, production techniques, enterprise combinations,
machinery complements, types of management, soil productivities, water
qualities, cotton allotment acreages, and possibly others.
A sample can only be drawn on the basis of hypotheses as to farm
characteristics presumed to have the most direct bearing on the question
The sampling procedure employed in this study was outlined
under study.
in Chapter 11.
Lied area.
The population sampled was individual farms in the speci-
The primary basis upon which the sample was drawn was farm
size because economics of size will significantly affect adjustments to
a changing land and water base.
It was felt that size of farm in crop-
land acres would most appropriately reflect economies of size and, hence,
most nearly represent a basis for projecting probable adjustments in the
agriculture of the area.
On this basis, the population of farms was arrayed according to
cropland acreage and a 20 percent sample of the farm numbers was drawn.
Large farms were sampled more heavily than small farms in order to obtain
a sample weighted in terms of acres, as well as farm numbers.
Number of
farms sampled, number of farms in the population, and aggregate cropland
acreage in each sampling range for the SRP and RWCD are presented in
Tables 4 and 5.
33
Table 4.
Range of Cropland Acreage3 Total Number of Farms, Aggregate
Cropland Acreage, and Number of Farms in Sample, SRP, 1964.
Cropland
Total Number
Aggregate
Number of Farms
Acrea.e Rart:e
of Farms
Cro.land Acrea:e
in Sample
30-
199.9
223
22,320
16
200-
599.9
106
42,768
28
600-1,199.9
42
37,728
28
1,200 and Above
23
41,184
18
Table 5.
Range of Cropland Acreage, Total Number of Farms, Aggregate
Cropland Acreage, and Number of Farms in Sample, RWCD, 1964.
Crop1 and
Total Number
Aggregate
Number of Farms
Acreage Range
of Farms
Cropland Acreage
in Sample
30-199.9
200 and Above
90
9,000
6
45
18,000
6
Sample Characteristics
After the survey was completed, an analysis of factors which
affect economies of size was undertaken.
It was concluded that a signif-
icant correlation existed between cropland acres and other factors of
production such as number of crawler and wheel tractors, amounts and
types of custom operations performed, irrigation water sources and
supplies, number of irrigation wells, number of full-time nonsupervisory
employees and number of hired supervisors.
These productive resources
greatly influence economies of size which, in turn, affect adjustments
that were specified in the objectives of the study.
Definition of Size Categories
Model sizes within each acreage range described in Tables 4 and
5 were determined by dividing the number of farms into the aggregate
acreage included in each acreage range.
As such, the models represent
34
averages within size groups.
The models are referred to as Size Groups
I through IV for the SRP and Size Groups I through II for the RWCD.
These are identified in Tables 6 and 7.
Table 6.
Salt River Project Farm Model Sizes.
Group Classifications
Cropland Acreage Range
Model Size
(Acres)
I
30-
199.9
100
II
200-
599.9
400
600-1,199.9
900
III
IV
1,200 and Above
1,800
Table 7.
Roosevelt Water Conservation District Farm Model Sizes.
Group Classifications
Crpland Acreage Range
Model Size
(Acres)
I
II
30-
199.9
200 and Above
100
400
Production Resources
A detailed description of all major production resources and their
relevant characteristics for this analysis can be found in a Department
of Agricultural Economics file report series (Mack, 1968).
The information
presented in that report describes in great detail the resource base,
enterprise combinations, costs and returns of enterprises and basic linear
programming matrices for each representative farm model.
Although the
file report is supplemental to this dissertation in an informal sense,
it will be referred to in the remaining parts of this work and can be
obtained from the Department of Agricultural Economics or author upon
request.
35
Because of the importance of several major production resources
to the analysis in Chapter IV, a brief review of these factors is presented
here.
A reiteration of their magnitudes and accompanying assumptions
follow.
Land
All land within each representative farm model, as well as
between models, is assumed to be homogeneous in productive capacity.
It
is readily granted that differences do exist throughout the study area;
however, the degree and extent to which soils do vary is not always a
major factor as to resource use and yields obtained.
More often, manage-
ment as to types of land used to produce different crops is the relevant
var jab 1 e.
Throughout the study area, soils are generally deep, well suited
to the types of crops grown, and require similar inputs of productive
factors necessary to produce alternative crops.
Irrigation Facilities
A complete and accurate listing of all irrigation equipment was
obtained in the farm survey.
This included wells, pumps and ditches.
Other minor irrigation equipment such as shovels, ditch checks and
siphons are included under small tools.
A synthesis of these data on a
representative farm model basis can be found in the supplemental report
(Mack, 1968).
Representative model facilities and their costs are
presented in Table 8.
36
Table 8.
Group
Irrigation Well and Ditch Inventory and Investment for Typical
Farm Models, SRP and RWCD.
Wells
SRP
RWCD
Concrete Ditches
Number
Investment
Number
Miles
Investment
Investment
(Dollars)
(Dollars)
(Dollars)
I
0
0
0
0
.5
3,300
II
2
45,302
.6
13,590
2.5
16,500
III
3
64,184
4.5
29,700
IV
6
135,906
9.0
59,400
Mack, 1968.
Source:
Larger farms were found to have a greater total investment in
irrigation facilities; however, the investment per acre was lowest on
farms having no irrigation wells.
Buildings
Farm building inventories were obtained for each farm surveyed.
The range and type of buildings on farms in each size category were found
to be quite diverse.
In many instances farms had buildings which were
not being employed in their present enterprise organization.
When syn-
thesizing the typical building inventory for each size group, buildings
not currently in use were excluded on the assumption that they had no
value in the operation and would not be repaired or replaced.
Most farms surveyed had some type of shop building(s); however,
their size, condition, and age varied considerably.
Labor and management
housing was typically present on farms in the larger size groups.
Farms
in the largest size group always had some type of office building
however,
the range in their value was considerable.
A complete summary of
buildings by size group can be found in Table 8 of the supplemental
37
report (Mack, 1968).
sented.
Their corresponding sizes and values are also pre-
These values for representative model farms are indicated in a
later section of this chapter.
Water Availability
A general outline regarding the sources and availability of water
by irrigation districts has been presented elsewhere in this Study (see
Chapter II, Water Supply Organizations).
However, as noted, water avail-
ability varies between irrigation districts and among representative farm
models.
In the SRP, water is available under five different categories
(Mack, 1968 and Smith, 1968).
Thee are assessment, normal flow, stored
and developed, project pump and private pump.
These sources, however,
are not relevant as far as each size group is concerned.
Assessment water up to two acre-feet is delivered upon request
to all project lands once the basic assessment has been paid.
Normal
flow water is, likewise, delivered upon demand to land having a normal
flow right (see Chapter II, Water Supply Organizations).
Although not
all project lands have a normal flow right and not all such rights are
fully used, an average of one-half acre-foot per acre of this right for
all cropland is assumed (Mack, 1965 and Smith, 1968).
Stored and developed
water is allocated, depending upon its availability, but has typically
amounted to one acre-foot per project acre (Salt River Valley Water
Users' Association, 1962).
This amount is assumed to be available to
all cropland in the model farms.
38
Pump water available from SRP pumps can vary from zero to two
acre-feet.
As of 1967, 163,580 acres of project land had project pump
water rights of 242,376 acre-feet.
The opportunity to purchase this
right from the project is still available.
On this basis, it is assumed
that each acre of land employed in agriculture in the SRP has a project
pump water right of two acre-feet per acre.
In addition to project water,
private wells exist on all farms except those in Size Group I.
It is
assumed there is no limit on water obtainable from these wells.
Project water, in fact or by assumption in this study, is avail-
able to each size group in the SRP in equal quantities per acre.
The
only variation among size group models is that Group I farms have no
private pump water.
In the RWCD, project water is available on an equal share basis
to each acre.
The only limitation on project water is a three acre-foot
maximum per acre during the prorate period (see Chapter II, Water Supply
Organizations).
During the remaining part of the year there are no quan-
tity restrictions on water available from the project.
in this project have .6 of an irrigation well per farm.
Group II farms
Water from this
source is assumed to be available to all farms in this size group.
Machinery Inventory
A detailed machinery inventory for each of the typical farm
models based on data collected in the farm survey is presented in Tables
9 through 12 of the supplemental report (Mack, 1968:11-17).
These machin-
ery inventories for the various size models provide the basis for selecting
a power unit and implement size in the individual enterprise budgets.
If
an implement is available in the inventory, the operations for which the
39
machine is used are considered done by the farmer.
If a machine is not
listed, the operations performed by that machine are considered done on
a custom basis.
Tables 9 through 12 of the supplemental report (Mack, 1968) also
present machinery costs.
These cost estimates were determined by inter-
views with retail machinery dealers located throughout the study area.
It is assumed that inventories and costs of machinery will remain constant over time.
This is in line with the previous assumptions of a
constant level of technology and prices.
The value of machinery inven-
tories is presented in a later section of this chapter.
Custom Operations
Farm survey data indicated that many small farms did not typically
own the more expensive tillage and harvesting equipment.
performed by these machinery items were hired done.
Operations
The machinery inven-
tory of the previous section of this chapter and operations done on a
custom basis are negatively correlated.
This is to say that if a machine
is owned, the operation is not performed on a custom basis.
A complete listing of custom operations and their associated
costs is contained in Table 19 of the supplemental report (Mack, 1968:25).
Labor
The supply function for all classes of labor is assumed to be
perfectly price elastic; that is, any and all quantities of labor, or
number of laborers, can be hired at a constant wage rate.
line with the assumed condition postulated in Chapter I
This is in
(Assumptions)
that the price elasticity of all supply and demand relationships would
be considered perfectly elastic.
40
A comprehensive discussion of the various classes of labor is
presented on Page 19 and in Table 14 of the supplemental report (Mack,
1968:20).
Capital
An infinitely elastic capital supply function is assumed for the
study area, as well as for individual farm models.
It is assumed that
farm operators, as individuals and in the aggregate, may obtain as much
capital as they need at constant interest rates.
In reality, there is
a large variety of sources of capital, and individual farm operators may
be able to obtain increasing amounts of operating capital only at increasing costs.
This would not be the case, however, with regard to
large groups of farm operators.
An average efficiency in obtaining
capital is assumed.
Management
Many levels of management ability are found at any one time in
any sector of the economy.
In some instances, the range of abilities
may be as wide as the number of firms.
However, over time the less
efficient management will either improve or be driven out and in the
theoretical long run, perfectly competitive situation all management
will be homogeneous.
Management ability in this study is assumed to be homogeneous
within each size group as well as between groups.
This also embodies
the assumption that levels of technology and output are identical for
all operating units within specific size groups.
41
Alternative Enterprise Combinations
Cropping patterns differ tremendously among farms within the
study area.
Some farms specialize in the growing of specific crops,
while others are diversified and may grow as many as six crops.
The
farm survey indicated that speciality crops are grown principally on
farms represented by Size Groups II and III.
The farms represented by
Groups I and IV tend to be oriented more toward general diversified
field crops.
Table 21 of the supplemental report (Mack, 1968:20) pre-
sents an array of crops that might be specified as grown on the various
farm size models.
These crops are only alternatives and, in no case,
would all of them be grown on any single farm or specified as grown on
any one representative model farm.
Table 9 summarizes these alternative
enterprise possibilities.
Calendars of Operations and Budgets
A complete and detailed calendar of operations and unit budget
for each alternative crop for each farm size model are presented in the
supplemental report (Mack, 1968:29).
The kinds and types of operations
for each crop were obtained from the farm survey.
There was little
variance among farms as to oçerations performed and physical inputs in
the production of identical crops.
Consequently, calendars of operations
for individual crops are identical for all representative farm models.
Representative farm model budgets are composed of inputs, operations and equipment necessary to perform the operation.
Equipment
related to an operation is taken directly from the machinery inventory
(see this chapter, Machinery Inventory) of the relevant farm model.
Unit
Source:
Mack, 1968.
D-C specifies double-cropped.
An "X" indicates possible crop alternative.
X
X
X
X
X
X
X
X
X
a
X
X
x
X
X
X
X
X
X
X
X
X
X
X
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
x
1,800 Acre
Farm
x
Alternative Crop Enterprises Available to Typical Farm Models, SRP and RWCD.
Farm Model Size
900 Acre
100 Acre
400 Acre
Farm
Farm
Farm
Crop Enterprise
Short Staple Cotton
(Solid Planted)
Short Staple Cotton
(Skip-Row Planted)
Alfalfa Production and Pasture
Alfalfa Production
Alfalfa Establishment
Sugar Beets for Sugar
Barley
Grain Sorghum
b
Barley-Grain Sorghum D-C
Wheat
Lettuce (Spring)
Lettuce (Fall)
Potatoes
Carrots
Onion (Dry)
Table 9.
43
costs of an operation performed by a particular size and type of machine
on any given size farm model are taken from Young, et al., (1968).
Costs and Returns
Several types of costs and returns are discussed in this section.
The relevance of each will be covered in turn.
gross and net.
Returns are of two types:
The two kinds of costs discussed are variable and fixed.
Each of these cost and return concepts is related to the representative
farm models previously developed.
Yields, Product Prices and Gross Returns
Major field crop yields used in this study were obtained from
farm survey data.
These yields were closely comparable to yields given
in other Arizona published sources.
In some instances, however, it was
felt that irrigation district crop reports (SRP, 1962-1968 and RWCD,
1963-l968a) provided more complete and comprehensive data pertinent to
the present in contrast to the time the field survey was conducted.
This
was particularly the case with regard to vegetable crops.
Only one output level for each enterprise is specified in
Table 10.
Production theory states that optimum input-output levels
change as the cost of inputs varies.
This relationship with respect to
water use and crop yields could not be identified in the study area even
though there was considerable variation in individual user's water costs.
It was found that farmers, when faced with a physical water restriction,
adjust cropped acreage rather than water use per cropped acre.
When
confronted by high water costs, farmers discontinue its use on low value
crops rather than attempt to produce these crops at lower water-yield
Dry Onions
Carrots
Fall
Potatoes
cw t.
cw t.
cwt.
cwt.
cwt.
ton
day
Lettuce
Spring
day
Pa s tur e
cwt.
cwt.
ton
cwt.
260
390d
275d
475
32
34
6.5
25
4.5
25
41
33
2.00
2.30
3.10
4.10
5.20
2.50
2.50
25.00
.05/day
25.00
.05/day
2.50
3.00
34
cw t.
cw t.
2.50
32
1
cwt.
50.00/ton
.22
50.00/ton
.22
10.94
10.00
2.50
1,500
2,295
1,150
1,760
20
ton
acre
lb.
lb.
lb.
lb.
Alfalfa Hay
PastureC
Wheat
Barley-Grain Sorghum
Double-Cropped
Barley
Sorghum
Alfalfa Hay
(Early)
Grain Sorghum
(Late)
Barley
Grain Sorghum
Lint
Seed
Sugar Beets
(Sugar)
Pasture
Short Staple Cotton
(Skip 4x4)
(Solid)
Lint
Seed
Short Staple Cotton
950.00
897.00
825.50
1,230.00
1,352.00,
80.00
74.80
162.50
12.50
112.50
12.50
90.20
99.00
74.80
218.80
10.00
80.00
330.00
57.38
253.00
45.00
2.14 per
a
42.80
Support Payment
103.15
a
Diversion Payment
61.91
Support Paymenta
103.15
a
61.91
Diversion Payment
(Dollars)
Yields, Prices, and Gross Returns per Acre from Field Crops, SRP and RWCD.
Product
Crop
Unit
Yield
Price per Unit
Revenue
Government Payment
Table 10.
950.00
897.00
825.50
1,230.00
1,352.00
125.00
175.00
154.80
90.20
99.00
74.80
80.00
271. 60
552.44
463.76
Gross
Return
Source:
Table 10.
Mack, 1968.
See Foerman (n.d.) and Salt River Project, 1962-1968.
Average 10 sheep per acre for 25 days at $0.05 per head per day.
See Young, et al., 1968.
See Pawson and Nelson, 1966.
(Continued).
46
levels.
Based upon these two findings, only one water-yield relationship
is presented for each crop.
The import of this approach is that water users assume that so long
as it is profitable to apply any water to a crop, it should be applied at
the level of maximum yield.
When water price moves above this level, no
water should be applied to the crop.
The implicit production function is
therefore merely a point as illustrated below:
X
-ç
N
Water Input
At any water price lower than or equal to the breakeven price, ON
quantities of water are applied and yield is OX.
At any water prices
higher than the breakeven price, no water is used on that crop and it drops
out of production entirely.
Though the empirical validity of a function of this form is
dubious, farmers act as if it were true.
Farmer's response to growing
water scarcity, which is what is being projected in this study, will follow
this pattern and, hence, becomes valid for this analysis.
Product prices are those reported in Arizona Agriculture, 1967
(Cooperative Extension Service and Agricultural Experiment Station, 1967)
and Young, etal., (1968).
Where applicable, government price support pay-
ments are included as a separate item in computing gross returns.
Table
10 presents a summary of yields, product prices, government payments, and
gross returns.
47
Net Returns Over Variable Costs
Variable operating costs are those costs which are incurred in
the production of any one crop.
They are variable in that if the specific
crop is not produced, these costs are not incurred.
They are directly
related to the production of a specific enterprise and are sometimes
referred to as direct costs.
These costs are dependent upon the level
of output in the short run since varying amounts of certain production
factors can be changed over the production period.
In this study,
however, specified levels of variable inputs are assumed for each
enterprise.
Net returns over variable production costs determine the shortrun allocation of resources among alternative enterprises.
Enterprises
with greater net returns over variable costs contribute the greatest
amount of net revenue to cover fixed costs and provide a residual profit.
Variable costs for producing each enterprise on each representative farm
model are presented in Table 11.
These costs are transcribed directly
from the unit budgets of each crop which are presented in the supplemental
report (Mack, 1968).
Total variable operating costs subtracted from
gross returns of Table 11 yields net returns.
The net returns are inclusive of variable water costs since
operating costs, as used herein, do not include the cost of water.
Water
cost, being one of the variables included under the objective of this
study, will be brought into the analysis later in negative quantities
in the objective function of the linear programming matrices.
In Table 11, net returns do not show clear economies of size for
all enterprises.
This is due to two factors:
transportation costs.
hired management and
These two items are particularly high on the 400-
Alfalfa
(Hay and Pasture)
Alfalfa
(Hay and Pasture)
Alfalfa
(Hay only) 6.5 T.
Alfalfa
(Hay only) 4.5 T.
(Early)
(Skip-Row)
Sugar Beets
Barley-Grain Sorghum
Double-Cropped
Potatoes
Dry Onions
Carrots
Spring Lettuce
Fall Lettuce
Wheat
Barley
Grain Sorghum
(Late)
Grain Sorghum
Short Staple Cotton
(Solid Plant)
Short Staple Cotton
35.22
52.45
25.19
89.78
110.05
87.31
125.00
162.50
112.50
29.03
61.17
90.20
62.48
56.99
14.41
60.39
74.80
112.52
55.96
54.12
32.72
45.88
47.28
175.00
100.06
556.68
663.25
469.37
746,59
644.34
42.19
43.41
46.62
108.18
154.80
825.50
1,230.00
1,352.00
950.00
897.00
99.00
80.00
25.13
54.40
108.10
87.37
35.16
64.43
33.41
70.51
83.65
72.98
86.12
59.16
75.18
62.62
41.99
65.09
78.85
53.02
77.65
56.50
31.04
88.88
55.69
16.45
49.88
87.32
60.91
97.35
33.70
19.11
55.56
36.66
43.44
43.34
58.35
55.17
99.63
49.78
251.40
556.09
867.96
190.81
235.76
54.68
33.82
18.84
339.60
114.79
219.21
156.81
325.10
109.50
227.34
162.10
105.02
574.10
673.91
484.04
769.19
662.28
45.72
46.18
282.26
181.50
277.06
Reb
turns
Net
1,800 Acre Farm
Total
Operating
Costs
186.70
900 Acre Farm
Total
Net
OperReating
b
turns
Costs
and Net Returns per Acre,
54.74
268.82
566.75
842.63
203.41
252.66
56.51
32.59
324.23
114.02
278.78
89.84
110.57
228.21
157.58
268.15
89.95
284.29
181.65
552.44
271.60
185.98
237.89
225.87
463.76
(Dollars)
Farm Model Gross Returns, Total Variable Operating Costs,
SRP and RWCD.
400 Acre Farm
100 Acre Farm
Total
Total
Net
Net
OperOperReGross
ating
Reating
b
b
a
turns
Returns
Costs
Costs
turns
Crop
Table 11.
Source:
Table 11.
See text.
Unit budgets, supplemental report (Mack, 1968).
Net returns are inclusive of water costs.
Taken from table 10.
(Continued).
50
and 900-acre farm models.
Their magnitudes and allocation among crop
enterprises are discussed in Mack (1968).
Their effect is largely to
eliminate economies of size from many of the crop enterprises appearing
in the agriculture of this area.
Fixed Costs
Fixed costs are defined as those incurred regardless of the
level of output.
They continue as long as the basic producing plant
is maintained without regard to output.
typical short run.
They cannot be varied in the
Over a long time span, longer than the usual yearly
production period for agricultural field crops, they are subject to
change by disposal by any one individual farm unit.
However, since this
study deals with the aggregate of all farms that compose the area, fixed
resources and their attendant costs will always exist so long as production
continues in the aggregate.
Fixed costs for each representative farm model are presented in
Table 12.
Fixed costs, as usually presented on an individual farm basis,
include an opportunity cost for real estate investment.
However, since
land values are dependent upon the availability of buyers and since
buyers will be available as long as agriculture produces a net return
to land, and since this study is concerned with agriculture as an aggregate rather than with farms as individual business entities, an opportunity
cost for real estate does not exist within agriculture and is not included
here among the fixed costs.
Total Investment per arma
Annual Amortized Cost
Annual Insurance
Annual Repair Cost
Total Annual Cost per Farme
Total Investment per Farm
Annual Amortized Cost per cre
Total Annual Cost per Farm
15.
16.
17.
18.
14.
13.
Taxes
12.
11.
10.
9.
Real Property Tax on Landtm
Real Property Tax on Wells
Real Property Tax on Buildings
Personal Property Taxes
Irrigation District
Total Taxes per Farmr
Total Investment per Farm1
Annual Amortized Costj
Annual Insurance Cost
Total Annual Cost per Farm
Machinery Inventory
8.
7.
6.
Irrigation Facilities
5.
4.
3.
2.
1.
25500q
500.00
0.00
10.80
70.58
26,140.00
3,551.59
26.14
3,577.73
3,300.00
2.58
258.14
1,200.00
93.87
6.00
24.00
123.87
100 Acre
1,005.
4,31451v
1,600.00
1,380.00
54.00
275.51
00q
102,040.00
13,863.96
102.04
13,966.00
12.08
4,831.59
61, 764. 00
6,000.00
469.36
300.00
120.00
889.36
93,880.00
8.16
7,344.55
10,400.00
813.56
520.00
208.00
1,541.56
3,600.00
1,920.00
126.00
477.58
2,255.00
8,378.58
176,880.00
24,032.31
176.88
24,209.19
(Dollars)
Model Size
900 Acre
400 Acre
Annual Fixed Costs for Typical Farm Models, SRP and RWCD.
Farm Buildings
Table 12.
7,200.00
3,840.00
216.90
821.62
4,505.00
16,583.53
304,305.00
41,345.00
304.31
41,649.59
195,300.00
8.49
15,277.65
24,100.00
1,885.26
1,250.00
482.00
3,617.26
1,800 Acre
(Continued).
48.
70.00
l2
4,866.
100 Acre
220.00
(Dollars)
600.00
47,473.30
52.74
Model Size
900 Acre
400 Acre
1,150.00
78,278.02
43.48
1,800 Acre
years.
years.
From Tables 9, 10, 11 and 12, supplemental report (Mack, 1968:11-17).
Line 7 times model size.
Amortization cost includes depreciation and interest on investment at six percent for 30
From Table 7, supplemental report (Mack, 1968:9).
Amortization cost includes depreciation and interest on investment at six percent for 10
All machines are assumed to be depreciated to zero value at the end of 10 years.
f,
Sum of lines 2, 3 and 4.
Annual repair cost is assumed to be two percent of total investment.
Average valuation is one-half
Amortization cost includes depreciation and interest on investment at six percent for 25
Annual insurance cost is based on $1.00 per $100 valuation.
of total investment given on line 1.
years.
repaired.
Does not
Value given is new cost.
From Table 8, supplemental report, (Mack, 1968:9).
include owner's home, labor housing or any buildings which are not in use and would not be replaced or
Personal Liability Insurance5
Total Annual Fixed Cost per Farm
Average Annual Fixed Cost per AcreU
Miscellaneous
Table 12.
Tax estimates of real estate are based on farm survey data.
Sum of lines 10 and 11.
Annual insurance costs are based on $0.20 per $100 valuation.
(Continued).
Assessed valuation is assumed to
Assume tax rate of $9.00 per $100 of assessed valuation.
be three percent of line 9.
above.)
-
These amounts are for farms in the SRP.
Line 20 divided by model size.
Sum of lines 5, 8, 12, 18, and 19.
They will differ for farms in the RWCD.
Estimates based on amount and type of machinery and number of employees.
Sum of lines 13, 14, 15, 16, and 17.
(See "q"
This is the irrigation assessment cost per farm in the SRP.
It includes an account charge of
$5.00 and a per acre assessment of $2.50 in the SRP. In the RWCD assessment charges are $7.00 per acre.
To determine irrigation district assessment charges in the RWCD, multiply model sizes I and II by $7.00
and substitute these figures for the SRP assessment charges for models I and II shown in the table.
Assessed valuation is assumed to
Assume tax rate of $9.00 per $100 of assessed valuation.
be 10 percent of line 1.
Assume an average pump
Average valuation is one-half
Tax on wells is based on estimates by Nelson and Busch, (1967:32).
horsepower of 200.
1.
of line 9.
k.
Table 12.
CHAPTER IV
THE LINEAR PROGRAHf'1INC MODEL
The specific problem considered in this study involves (1) estimating the value of varying quantities of irrigation water within each
of the farm model groups and the aggregate study area and (2) determining
enterprise adjustments and outputs as the quantity of land and the price
of water is varied.
resource programming.
This is a combination of variable price and variable
A detailed analysis of this procedure is presented
by Heady and Candler (1958, Chapters 7 and 8).
Values for and adjustments to resource prices and quantities and
their changes are determined within each of the representative farm models
specified in Chapter III (Definition of Size Categories).
The individual
farm model results are then aggregated to determine resource values and
quantities used and enterprise adjustments for the entire study area.
Procedural Technique
Resource valuation on the individual farm is a typical problem
in production economics since such valuation is implicit in the allocation
of resources among competing enterprises.
One method whereby a resource
can be valued is to consider the firm within which it is being used to
be operating at its short-run economic optimum and then to determine
how an increase or decreas9 in the resource under consideration by unit
amounts affects net revenue of the firm.
This procedure is typically
referred to as variable resource programming.
54
Variable price progralahting
55
is quite similar with the exception that resource or activity prices
are varied and adjustments in resource use or activity levels and mix
are noted.
Several methods are available by which resources can be properly
distributed among a variety of competing uses.
If alternative uses and
available resources are few in number, the problem is quite simple and
can be handled rather easily by a budgeting process.
If, however, a
large number of enterprise activities and resources are available,
budgeting is a very inefficient means of obtaining optimum solutions
and resource values at the margins.
Linear programming has proven well adapted to this type of problem.
A brief general exposition of the linear prograulluing technique is pre-
sented to show how it is related to solving the problem under study.
A
more complete development of this technique can be found in Dorfman,
Samuelson and Solow (1958) or Heady and Candler (1958).
Linear programming, in its most basic form, is an analytical
technique used to solve a system of simultaneous equations.
programming problem is composed of the five following parts:
Any linear
(1) an
objective function, the value of which is to be maximized or minimized
and which yields estimates of returns to or costs of each activity at
such maximum or minimum level of value of the total function, (2) real
activities available to the producing unit, (3) disposal activities
allowing nonuse of productive resources, (4) artificial activities providing for required solutions and computational convenience and (5)
-
restrictions which specify the upper bounds of or limits on resources
available in the model.
The objective of the problem is to maximize or
56
minimize the objective function subject to the restraints imposed by
the limiting resources.
Production possibilities of the representative farm models can
be summarized in matrix form as follows:
aX
+a 122
X
111
+
+ainni
X<b
aX
X
211 +a 222
+
+a2nn
X<b2
aX
+a m22
X
ml 1
+
+amnn
X<bm
the b's (b1, b2 .... b) are quantities of various resources which are
limitational.
These are the restrictions.
In the farm models, these
are such factors as land and water quantities and acreage allotments
available to each model.
The coefficients, a
,
ii
a
12
.... a
mn
,
are the
input requirements of each enterprise for each of the limitational
resources.
These are the production coefficients.
The columns contain all input coefficients (say a1
... .
am) for
each activity (say X1) and the rows contain the input coefficients (say
a1 .... a) for each resource.
Thus, a11 is the amount of b1 required
to produce one unit of the first activity (X1) listed in the matrix.
The X's are the unknowns and represent the to-be-determined levels at
which each activity will be carried on.
These are the real activities.
The inequalities indicate that no more of a resource may be used than
is available, but some of it may go unused.
Nonuse of a resource is
provided for in the matrix by the presence of disposal activities.
Defining C. as unit net revenue above specific variable costs
for the jth activity, and with maximum profit as the objective, the
57
optimum use of resources is achieved when the quantity C1X1 + C2X2
+ .... + CX is at a maximum subject to the inequality restrictions of
the production possibilities matrix.
This is the objective function and
may contain negative, as well as positive, coefficients.
The algebraic
summation of the C X function is total net revenue over variable pronfl
duction costs.
The marginal unit value of any particular scarce resource is the
amount by which the value of the objective function (z C.X.) would be
reduced by limiting the availability of that resource by one unit, while
holding all other resource restrictions constant.
Most computational
schemes contain a process whereby the marginal values of limiting
resources are determined and presented simultaneously with the optimum
solution.
A complete schedule of marginal values for a resource may be
derived by an approximate series of programming steps (Heady and Candler,
1958, Chapter 7).
These values represent the prices that would be paid
for various quantities of the resource under the assumption of profit
maximization; that is, a demand schedule for that input or resource.
Ideally, a program with a parametric-objective function would be employed
in this procedure.
However, by varying the resource in a nonparametric
program for which a demand function is being developed, a close approximation to a parametric solution can be developed.
Several assumptions are implicit in the linear programming procedure described above.
These are in addition to the assumptions stated
in Chapter I (Assumptions).
Briefly, these assumptions are:
(1) addi-
tivity and linearity, (2) divisibility, (3) finiteness, (4) single-value
expectations, and (5) profit maximization.
A complete discussion of these
58
and their particular relevance can be found in Heady and Candler
(1958: 17-18).
Components of the Models
Component parts of a linear programming model were discussed in
the previous section of this chapter.
Three of these parts and their
relative magnitudes for the specific problem in this study are presented
below.
Much of the data presented here is in summary form and can be
found in appropriate preceding sections of this study or in the supplemental report (Mack, 1968).
The supplemental report also contains a
linear programming matrix for each model farm.
The Objective Functions
An objective function (six in all) is developed for each of the
six model farms in the SRP and RWCD.
These functions contain net revenue
coefficients from Table 11 for all enterprise activities on each model
farm, as indicated in Table 9.
Unit water costs as negative quantities
are also contained in this function.
Water is available in varying
quantities under several cost situations.
These quantities and costs
are developed later; however, their general structure is presented in
Table 13 of this chapter.
Real Activities
The range of alternative enterprise combinations constitute the
real activities in the models.
These are presented in Table 9.
In
addition to real activities, disposal activities, which provide for
nonuse of resources, are incorporated in each model and represent solutions to each of the problems.
59
Table 13.
Aggregate Water Availability and Cost by Size Group, SRP,
1967.
Size Group
Water Type
II
I
III
IV
Variable Cost
per Acre-Foot
(Acre-Feet)
Assessment
Normal Flow
Stored and Developed
Project Pump
Private Pump
44,640
11,160
22,230
44,640
0
85,536
21,384
42,768
85,536
(Dollars)
75,456
18,864
37,728
75,456
a
a
83,552
20,888
41,776
83,552
0.00
2.00
2.00
a
6.44
750b
Size Group II has two sells per farm; Group III has three;
and Group IV has six. No restriction is placed on quantity that can be
pumped from these wells.
Cost based on 2.34 cents per acre-foot per foot of lift,
1967 lift of 280 feet.
Restrictions
Each representative farm model has a number of restrictions.
These are based on the physical and institutional characteristics of the
study area.
Their magnitudes as of 1966 and 1967 are developed from farm
survey and aggregate study area data sources.
Two of these restrictions,
land and water, are varied at a later stage in the analysis.
All other
restrictions remain invariant throughout the entire analysis.
Available cropland in the SRP currently totals 144,000 acres.
This is divided among farm models, as indicated in Table 4.
Cotton allotment acreage varies according to model size.
The
farm survey data indicated that smaller farms had a larger cotton allotment
in relation to farm size than larger farms.
Based on the 1967 cotton pro-
gram (United States Department of Agriculture, 1967) acreage allotment
restrictions and diversion use balances are placed on the models as shown
in Table 14.
b
b
83,552
54,000
b
5,000
2,200
2,200
2,200
200
850
750
390
200
18,000
18,000
4,905
2,646
II
Group II in RWCD has
27,000
a
1,100
1,100
1 , 100
2,500
200
9,000
9,000
2,457
1,323
I
RWCD Size Group
Some crops use land
Land A refers to uses
Group II, III and IV farms in SRP have 2, 3 and 6 wells, respectively.
75,456
b
85,536
a
44,640
83,552
20,888
41,776
LandsA and B refer to land availability by production time period.
throughout the entire production period while others use only land A or land B.
from January 1 to May 31 and land B to uses from June 1 to December 31.
.6 well.
13,728
10,296
10,296
10,296
2,000
41,184
5,086
2,739
41 , 184
(Acre-Feet)
37,728
37,728
7,112
3,829
2,000
1,000
400
550
400
1,000
900
12,576
9,432
8,432
9,432
75,456
18,864
37,728
10,692
10,692
350
550
250
600
600
15,246
10,692
42,768
42,768
8,895
4,790
1,500
1,000
85,536
21,384
42,768
44,640
11,160
22,320
7,440
5,580
5,580
5,580
22,320
22,320
5,078
2,734
No private pump water available.
Assessment Water
Normal Flow Water
S & D Water
Private Pump Water
Project Pump Water
Summer Prorate Water
Land AC
Land BC
Cotton Allotment
Diversion Use
Wheat Allotment
Sugar Beet Allotment
Spring Lettuce
Fall Lettuce
Potatoes
Carrots
Dry Onions
Alfalfa
Barley
Sorghum
Barley-Sorghum
(Acres)
Constraints for Aggregate Model Farms, SRP and RWCD, 1967.
SRP Size Group
Constraint
I
II
Iv
III
Table 14.
61
Initial acreage restrictions are placed on the models in terms
of limits on alfalfa, barley and sorghum.
SRI' limits on alfalfa are set
at no more than one-third of the available cropland.
Limits on barley
and sorghum are set at no more than one-fourth of the available cropland.'
RWCD limits on alfalfa are set at 27 percent and barley and sorghum limits
at 12 percent of available cropland.
These fractions and percentages of
crop limits in the SRI' and RWCD reflect the typical acreages of these
crops presently grown in each project.
Cotton allotments in the SRP, as a percentage of available cropland, are varied as available cropland changes.
No more than one-third
of the available land in any model farm may be allocated by the solution
to cotton.
This restriction has the affect of forcing a rotation pattern
on land use in that it prevents cotton from occupying all land as the
land base declines relative to available cotton allotment, and, thereby,
allows other crops to be grown or cropland to remain idle.
Rotational cropping practices in this study are based on agronomic
requirements and disease and insect control considerations.
Cotton is
generally thought to be the primary recipient of rotation benefits.
Available literature and discussion with agronomists suggest that a
cotton-alfalfa-small grain (or root crop, such as sugar beets) cropping
pattern is desirable.
Allowing land to lie fallow may also be an acceptable
disease or insect control measure in a rotation.
In the area studied herein, rotational crops such as alfalfa,
sugar beets, and small grains will not be entirely forced out of production due to water scarcity.
This is in contrast to conditions projected
for Pinal County (Stults, 1968).
In Pinal County, land abandonment by
62
rotational crops and restrictjons on cotton acreage by cotton allotments
will insure ample acreages of idle cropland for disease and insect rotational purposes.
Hence, in the study reported herein,
a restriction on
cotton acreage was necessary to insure an adequate area of rotational
lands for agronomic purposes.
The quantity of water available to each representative farm
model in the SRP is presented in Table 13.
Water quantity is restrictive in the RWCD only during the prorate
period, as explained in Chapter III (Water Availability).
During this
prorate period Group I model farms have available a total quantity of
27,000 acre-feet of district water and Group II model farms have 54,000
acre-feet of district water, plus 20,670 acre-feet of private pump water
available to them.
Project water is priced at $8.50 per acre-foot and
private pump water, obtained from a depth of 457 feet (1967), costs
$10.50 per acre-foot.
Table 14 presents a summary of all initial model constraints.
Variations in Water Quantity
The productivity of a resource in its last or final use among a
variety of uses is its marginal product.
Its marginal product multiplied
by that product's price is the marginal value productivity of that
resource or the price a user would be willing to pay to obtain one more
unit of resource for use in that production process under the assumption
of profit maximization.
Alternative quantities of irrigation water available to each farm
model are specified in this section.
Each model is first assumed to have
no water and optimum solutions are obtained.
Water is then varied in each
63
model in a succession of one-half acre-foot increments up to six and
one-half acre-feet per acre.
These quantities for the total acreage
represented by each model are presented in Table 15.
quantities are referred to as "revisions."
Alternative water
After each revision, a solution
is obtained and the marginal value productivity of "shadow price" of that
additional water quantity for each model is obtained.
Shadow prices for
all other limiting resources contingent on that level of water use are
simultaneously determined.
These shadow prices are the increases in net
revenue that could be obtained in each farm model if one more unit of the
limiting resource were available.
Thus, by varying the water quantity
from zero to some quantity such thac the shadow price becomes zero and/or
some quantity of water goes into a disposal activity (goes unused), it is
possible to develop a quantity-price relationship or demand function for
irrigation water within each model.
An addition of aggregate model
demands provides the data necessary to construct an aggregate demand
schedule for irrigation water (Moore, 1962:132).
Variations in Land and Water
Availability Over Time
This section presents projected changes in the availability and
costs of selected resources over time.
are the variables considered.
Land availability and water cost
The projection span is from 1967 to 2020.
Changes are considered at five-year intervals, beginning in 1970.
Land Availability
Past and present urban and industrial land use versus agricultural
land availability is presented in Chapter I (Land Availability and Use).
Agricultural land availability projected to 2020 is developed in this
64,152
33,480
44,640
55,800
66,960
78,120
89,280
100,440
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
4
5
6
7
8
9
10
11
226,368
245,232
235,224
256,608
277,992
122,720
133,920
145,080
6.5
6.0
6.5
12
13
207,504
213,840
188,640
169,776
150,912
132,048
113,184
94,320
75,456
56,592
37,728
111,160
192,456
171,072
149,688
128,304
106,920
85,536
42,768
22,320
1.0
2
18,864
21,384
11,160
0
0
III
0
II
SRP Size Groups
.5
0
0
I
1
tity/
Acre
No.
Quan-
Total
Thousands
0
267,692
247,104
226,512
205,920
185,328
164,736
144,144
123,552
102,320
82,368
61,776
41,184
936
864
792
720
648
576
504
432
360
288
216
144
72
0
(Acre-Feet)
20,592
IV
0
58,500
54,000
49,500
45,000
40,500
36,000
31,500
27,000
22,500
18,000
13,500
9,000
4,500
I
0
117,000
108,000
99,000
90,000
81,000
72,000
63,000
54,000
45,000
36,000
27,000
18,000
9,000
II
RWCD Size Groups
175.5
162
148.5
135
121.5
108
94.5
81
67.5
54
40.5
27
13.5
0
Total
Thousands
Aggregate Water Quantity Variations in One-Half Acre-Foot Increments from Zero to Six and
One-Half Acre-Feet per Acre, SRP and RWCD.
ReviSion
Table 15.
65
section.
Theile (1965) and Western Management Consultants, Inc. (1965:
147) have projected land availability in the agricultural sector.
Theile's
(1965) projections are for the Phoenix Metropolitan Area, which includes
the area under study here.
Western Management Consultants, Inc. (1965:147)
projections are based on historical SRP data and appear overly restrictive.
Agricultural land projections for the SRP, as developed in the
present study, are based on the relationship
Y is agricultural land.
upon SRP hisotrical data.
+
(.9765)
where
Wyatt (1968) developed this relationship, based
Table 16 presents these acreage projections
in total and by farm size group.
Since farms of all sizes are randomly
located throughout the project, total acreage declines are distributed
proportionately among farm size groups.
Transfers of land among size
groups are assumed not to occur due to the rapid decline in total project
acreage.
RWCD agricultural land availability is assumed to remain constant
over the period of time under consideration in this study.
Groundwater Table Projections
Three groundwater subareas, as determined by United States Geo-
logical Survey (White, Stulik and Rauh, 1964) underlie the study area.
These are referred to as the Phoenix-Glendale-Tolleson-Deer Valley area;
the Tempe-Mesa-Chandler area; and the Queen Creek-Higley-Gilbert-Magma
area.
They are presented in Figure 1 (Page 4).
The SRP is almost wholly
contained within the first two subareas, while the RWCD is entirely within
the third subarea.
These subareas differ somewhat in groundwater condi-
tions, as well as differing within areas.
Changes in depth to water and
rates of groundwater decline have been observed, both within and between
areas (White,
al., 1964 and Cox, 1968).
57,211
50,798
45,100
40,040
35,522
67,116
59,590
52,907
46,974
41,707
370,600
329,048
292,142
259,379
230,295
2000
2005
2010
2015
2020
7
8
10
11
7,280
6,464
10,402
9,236
8,200
14,862
13,196
11,716
21,233
18,852
16,739
76,730
68,123
109,631
97,339
86,421
13,951
12,386
67,688
60,098
96,712
85,866
76,235
12,307
10,927
17,584
15,612
13,861
25,122
22,306
19,805
138,171
122,683
108,927
28,478
25,286
22,451
156,629
139,073
123,480
19,933
17,698
15,713
39,726
35,272
31,318
218,493
193,996
172,249
35,890
31,867
28,294
197,395
175,268
155,617
40,685
36,124
32,074
223,767
198,682
176,407
79,921
66,522
107,046
95,045
84,386
13,622
12,095
19,463
17,281
15,343
27,807
24,690
21,922
41,776
229,768
37,728
207,504
42,768
235,224
152,938
135,795
125,571
(Acres)
(AcreFeet)
(Acres)
(AcreFeet)
(Acres)
(AcreFeet)
data.
Acreage projection derived from observed relationship
(.9765) (Ye) where Y equals
+ 1
irrigated acreage. Total acreage is then distributed among size groups on the basis of observed 1967
Total available water is composed of two acre-feet of assessment water, one-half acre-foot
normal flow water, one acre-foot stored and developed water and two acre-feet of project pump water.
9
6
5
81,741
75,578
64,006
529,479
470,129
414,116
1985
1990
1995
4
3
95,888
85,139
75,593
116,781
103,686
92,064
756,436 136,988
671,632 121,630
596,337 107,995
1970
1975
1980
2
1
22,320
122,760
(Acres)
(AcreFeet)
795,256 144,000
(Acres)
1967
(AcreFeet)
Pro'ected A:ricultural Land and Irri:ation Water Availabilit over Time, 1967-2020 SRP.
Aggregate Size Groups
IV
II
III
Totals
I
Year In
Waterd
Landb
Watera
Landb
Landb
Landb
Watera
Landb
Watera
Watera
Future
0
Revision
Number
Table 16.
67
Theile (1965) has consolidated the Tempe-Chandler and Queen CreekHigley subareas into a Mesa Basin and refers to the Phoenix-Glendale
subarea as part of the Phoenix Basin.
These two basins encompass all SRP
and RWCD land, plus outlying parts of central Arizona.
Nonagricultural water use based on population projections (City
of Phoenix and Maricopa County, 1959a) estimate that 1.5 million acre-feet
of water will be required by the year 2020.
Population in. 2020 is esti-
mated to be three million people (Theile, 1965).
Much of this projected
development is expected to take place on land now occupied by agriculture.
Hence, a decline in agricultural land (this chapter, Land Availability)
will be accompanied by a proportionate decrease in the availability of
project supplied water to agriculture since water is appurtenant to the
land.
No data exist as to water use on an urban-industrial acre relative
to an acre of agriculture land as the individual acre(s) are transferred
between uses.
The official position of the SRP is that total water
requirements have not changed with the transfer of land out of agricultural
uses.
Smith (1968:152) found that the transfer of land out of the agri-
cultural sector decreased project water use; however, he also states that
residential and municipal uses can be expected to increase ona per
capita basis (Smith, 1968:163).
Thiele (1965:21) also predicts an
increasing per capita consumption of water in the urban-industrial sector.
He states that, "Records show a steady increase (in per capita water use)
as new household conveniences are developed
.
.
.
The past trends show
that commercial and industrial water use increases on a per capita basis
(over, time).
the future."
There is nothing to indicate a reversal of these trends in
68
On the basis of the preceding discussion, total water use is
assumed to remain unchanged as land moves from agricultural to urbancollilLiercial uses.
Consumptive use of water may change, however, due to
the reclamation of water used in the urban-industrial sector.
This may
have an effect on groundwater recharge depending upon the use made of
reclaimed water.
Presently, no conclusions on this point can be analyt-
ically verified; thus recharge is assumed nonvariant.
Groundwater decline
rates are assumed to be constant since no change in withdrawals or
recharge is predicted.
Thiele (1965), using his areas of the Phoenix and Mesa groundwater basins, has estimated annual rates of groundwater decline at six
feet in the Phoenix Basin and seven feet in the Mesa Basin.
United
States Geological Survey (White, et al., 1964 and Cox, 1968) data for
this same area indicate a range of from small increases to 60-foot declines
in the water table from the spring of 1962 to the spring of 1966.
This
is depicted in Figure 2.
Groundwater decline rates in this study are assumed to be 6.5
feet per year in the SRP, which partially coincides with Thiele's Phoenix
Basin and seven feet per year in the RWCD, which is encompassed entirely
in Thiele's Mesa Basin.
A 1965 summer test survey of 173 SRP wells indicated an average
pumping lift of 280 feet.
A list of 42 RWCD wells tested for the same
time period indicated an average pumping lift of 457 feet.
These wells
are located throughout the projects and are interspersed with private
wells.
For purposes of this study, pumping lifts of private and project
wells are considered identical over the projection period.
Estimated
69
pumping lifts and groundwater decline rates over time are presented
in Table 17.
A constant rate of decline in the groundwater table and a constant rate of increase in pumping lifts assumes that groundwater decline
rates are independent of the quantity of water used in agriculture.
Since
this analysis projects a rapidly increasing urban-industrial sector onto
land now occupied by the agricultural sector, the validity of this
assumption appears sound in the SRP.
In the RWCD, however, some questions regarding the assumption of
a constant groundwater decline rate can be raised.
Stults (1968) adjusted
the rate of decline in the water table in proportion to changes in the
quantity of water withdrawn.
This method used by Stults appears well-
grounded when the water use area overlies the entire groundwater basin(s).
The RWCD, being one of several users of a single water basin (see Figure 1,
Page 4) exercises only a partial influence upon the water decline rate
of one basin.
An accurate prediction of decline rates over time would
have to take all withdrawals from the basin into account.
Since total
pumpage from the basin underlying the RWCD is beyond the scope of the
present study, a constant rate of decline in the groundwater table is
assumed.
Pumping Costs
Variability of per acre-foot costs of pumping water is primarily
a function of pumping lift.
Other factors that affect pumping costs
are the specific yield of the
aquifer, condition of pump, type of
pumping unit, and number of bowl stages.
be constants in this analysis.
These factors are assumed to
N
N
N
6,
Source:
Figure 2.
S
6
33
S
N
LANE
PLEA5ANT
4 2E
5:
N 4L
BEE
RBE
RIOE
1 SUPERSTITION MTS.
IH
-- GALlONS PtA MINUTE jGPNJ
Cox, 1968.
Depth to Water, 1967, and Change in Water Level, 1962-1967, in Selected Wells in the
Central Part of Arizona.
G1A BEND
-
33
0
71
Table 17.
Year
Estimated Pumping Lifts and Rates of Groundwater Decline,
1967-2020, SRP and RWCD.
SRP
RWCD
Rate of Decline
Lift
Rate of Decline
Lift
(Feet)
1967
6.5
280.0
7
457.0
1970
6.5
299.5
7
478.0
1975
6.5
332.0
7
513.0
1980
6.5
364.5
7
548.0
1985
6.5
397.0
7
583.0
1990
6.5
429.5
7
618.0
1995
6.5
462.0
7
653.0
2000
6.5
494.5
7
688.0
2005
6.5
527.0
7
723.0
2010
6.5
559.5
7
758.0
2015
6.5
592.0
7
793.0
2020
6.5
624.5
7
828.0
72
Pumping costs per acre-foot per foot of lift vary between irrigation districts and between districts and private farm pumpers.
Lamoreaux (1966), in a survey of seven irrigation districts in central
Arizona, found that average district variable cost per acre-foot per
foot of lift was 1.856 cents, while individual farmer costs averaged
2.334 cents.
RWCD variable costs per acre-foot per foot of lift were
found to be 1.683 cents, while SRP costs were 1.787 cents.
In addition
to variable pumping costs, an added capital cost for lowering pumping
plants must be included as pumping lifts increase.
Lamoreaux (1966)
estimated these added capital costs per acre-foot per foot of pumping
life to be .048 cents in the RWCD, .030 cents in the SRP and .110 cents
for privately owned and operated wells.
The total variable and added
capital costs per acre-foot per foot of lift for the RWCD thus was
1.731 cents, for the SRP it was 1.817 cents, and for private pumpers,
2.45 cents.
These unit costs per foot of lift, when multiplied by
pumping lift, provide estimates of total variable cost per acre-foot
for pumping water from various depths by each class of pumper.
Table 18
presents these costs for district pumps in the RWCD and for private
pumpers in both the RWCD and SRP.
No SRP pumping costs and lifts are presented in Table 18.
Approximately two-thirds of the water distributed by the SRI' is obtained
from surface sources.
The remaining one-third is pumped.
No increase in
the cost of surface supplied water is foreseen since no increase in
distribution costs is assumed.
The actual cost of pumping water by the
SRP may increase over the projection period, but the cost of project
pumped water to the individual farmer is assumed to remain constant over
73
Table 18.
Year
Pumping Lifts and Pump Water Costs per Acre-Foot for
Selected Years, SRP and RWCD.
SRP
RWCD
Private Costa
Lift
Lift
Project Costb
Private Costa
(Feet)
(Dollars)
6.44c
(Feet)
(Dollars)
850d
1967
280
1970
299.5
7.34
478
9.09
11.71
1975
332.0
8.13
513
9.69
12.57
1980
364.5
8.93
548
10.30
13.43
1985
397.0
9.73
583
10.91
14.28
1990
429.5
10.52
618
11.51
15.14
1995
462.0
11.32
653
12.11
16.00
2000
494.5
12.12
688
12.72
16.86
2005
527.0
12.91
723
13.33
17.71
2010
559.5
13.71
758
13.93
18.57
2015
592.0
14.50
793
14.54
19.43
2020
624.5
15.30
828
15.14
20.29
457
10.50
Includes 2.34 cents variable and .11 cents added capital
cost per acre-foot per foot of pumping lift.
Includes 1.68 cents variable and .048 cents added capital
cost per acre-foot per foot of pumping lift plus an .82 cent project
differential.
Includes variable cost at 2.34 cents per acre-foot per foot
of pumping lift.
Present 1967 cost of project pump water to users.
74
the study period.
The SRP does, however, state that "the rate for the
purchase of pump water is based on the actual cost of pumping and
delivering the water" (SRP, 1964).
The basis for the assumption in this Study that the cost to the
farmer-user of the SRP pumped water will remain constant is founded on
the
cooperative concept, which holds that the organization exists
to supply
a factor at the least possible cost to all users.
maintains and operates a system of hydro and thermal electric
The SRP
power
generating plants which typically have produced over 90 percent of total
project gross revenues.
Surplus funds from power revenues have been trans-
ferred to project water operations.
From 1962 to 1967, the average annual
transfer of power revenues to support water operations within the
over $5.6 million (SRP, 1962-1967).
to the need for water as
SRP was
Smith found that "the SRP responds
expressed by the requirements of water users
rather than regulating the requirement for water" (Smith, 1968).
Smith
further found that "the SRP emphasizes the ends and the means are adjusted
to attain the desired ends" (Smith, 1968).
Desired "ends" are low cost
irrigation water.
Adequate revenues from power have been available to subsidize
water operations on the part of the SRP.
It is assumed that this ability
to subsidize will continue at a level such that all project water costs
assessed against farm users within the SRP will not increase over time.
Thus, SRP supplied pump water is assumed to be available over time to
each farm model in the quantity and at the unit cost presented in Table 13.
This is in effect an assumption that net power revenues to the
SRP will
increase over future years at a rate sufficient to cover the increasing
75
variable and added capital costs of pumping from year to year as pumping
lift increases, as shown in Table 17.
Water Supply Functions
Water in Arizona is appurtenant to the land.
As the available
agricultural land decreases, the total project provided agricultural
water supply also decreases.
However, quantity of irrigation water avail-
able per irrigated acre remains constant.
Projected agricultural land and water availability in the SRP
is presented in Table 16.
Total projected land and water decreases are
assumed to be distributed over total acreage occupied by farms represented
by each farm model in proportion to the aggregate cropland acreage occupied
by farms represented by each model in 1967.
in Table 16 relate to SRP water only.
Water supply data presented
It is composed of the four classes
of project water explained in Chapter I (Water Sources and Rights) and
Table 13 of the present chapter.
They are exclusive of that which may be
supplied via private pumps on Groups II, III, and IV.
is assumed to be invariant over time.
Project water cost
Private pump water cost is assumed
to change, as indicated in Table 18.
RWCD water availability is assumed to remain constant over the
time span under study.
Each acre has a three acre-foot project water
limit during the prorate period (Chapter I, Water Sources and Rights).
No restrictions exist on project supplied water during the nonprorate
period.
Group I farms in the RWCD have no source of water other than
that supplied by the project.3
Group II farms have access to private
Water is transferable among farms on a private sale basis;
3.
however, very little water is, in fact, bought or sold.
76
pump water.
Project and private pump water cost is assumed to change
over time, as projected in Table 18.
Surface water obtained by the RWCD from the SRP (Chapter II,
Roosevelt Water Conservation District) varies between one-fourth and
one-third of the district's total water use (Goss, 1968).
The district's
costs of obtaining this surface water are less than for that water obtained
from underground sources; however, the individual farmer is charged an
average cost for all project water used.
The average water cost over
time to farm users in the RWCD, it is assumed, will increase at the
rate as per acre-foot pump water costs will increase.
same
This may introduce
an upward bias in water cost estimates in that the constant cost to the
RWCD of water it obtains from the SRP will tend to offset somewhat the
effect of an increasing cost to it of its own pumped water.
however, will be of minor significance.
The effect,
CHAPTER V
RESULTS AND CONCLUSIONS
Adjustments in optimum enterprise combinations at specified
resource levels and costs for each model farm group, in each district,
and for the total study area are presented in this chapter.
Changes in
water use, land use, and net revenue over variable production costs
steiiuiiing from optimum enterprise combinations under changing water and
land use conditions are analyzed.
Changes in numbers of farms and crop
acreages over the projection period are examined.
Net returns over
all costs as of 1967 are also developed.
In the concluding two sections, an agricultural demand function
for irrigation water as of 1967 is developed and an exploration of water
parameter variations over time is undertaken.
Additional water sources,
variations in water prices, and uses that would be made of additional
water at lower prices are explored.
Revenue generated over time steuuiiing
from these variations in water parameters and uses are also presented.
A concluding chapter sums and evaluates the findings of this study.
Projected Adjustments to
Resource Changes
Resource availabilities and costs over time and the rationale
supporting these estimates by farm size group and for all farms are
presented in Chapter IV (Variations in Land and Water Availability Over
Time).
Land and water quantity changes over time in the SRP are presented
77
78
in Table 18.
Time-related private and project pumping costs are pre-
sented in Table 17.
The effects of declining cropland availability and increasing
water costs on optimum cropping patterns, water use by supply sources,
and on total water use for each farm size group in the SRP and RWCD,
are presented in Tables 19 through 24.
Net revenue and water use pro-
jections are presented by farm size group, by irrigation district, in
total, and on a per acre basis in the remaining parts of this section.
Enterprise Combinations
Decreasing land availability and/or increasing water costs or
availability over time will affectthe acreages of various crops and
the enterprise mix.
Each size class of farms will adjust differently,
depending upon the range of its alternative crops and upon the relative
net returns it can generate from the crops included in its enterprise
mix.
All farm size models in both the SRP and RWCD will utilize
through 2020 under the assumptions made herein, all cropland acreage
available for the production of crops that generate a high value per
acre-foot of water used.
vegetables.
These crops are cotton, sugar beets, and
Alternative crops that generate a low return per acre-foot
of water used are incorporated into or excluded from optimum enterprise
mixes over time, as shown in Tables 19 through 24.
SRP Size Group I farms adjust enterprise acreages in alfalfa hay
and pasture and in barley.
Cotton acreage declines over time in line
with assumed rotation restrictions (Chapter IV, Restrictions).
Adjust-
ments in SRP farm model Size Group II take place in barley-sorghum and
2,117
1,421
1,198
1,168
5,078
5,078
4,954
4,390
3,705
3,467
3,079
2,800
2,420
2,155
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
See footnotes on Page 85.
1,036
1,298
1,480
1,667
2,903
3,311
5,479
5,078
1970
6,589
(Acres)
5,078
a
1967
Year
1,118
1,271
1,302
1,598
1,801
2,885
2,299
2,572
3,780
5,385
5,580
5,580
1,118
1,271
1,302
1,598
1,801
2,885
2,299
2,572
3,780
5,394
5,580
5,580
22,624
25,480
28,700
32,326
36,407
41,006
46,186
52,071
58,586
65,982
74,715
78,120
0
5,385
6,713
10,147
(Acre-Feet)
0
22,624
25,480
28,700
32,326
36,407
41,006
46,186
52,017
58,586
71,340
81,028
88,267
Projected Adjustments on Farms in Size Group I to Changing Land and Water Availability, SRP.
Alfalfa Hay
Idle
Cotton
Water Supply Sources
Total
b
and PastureC Barley h Land B i Projectm Project Pump
Skip-Row 4x4
Private Pump° Water Use
Table 19.
4,378
3,433
1,187
601
8,895
8,895
8,895
8,429
7,484
6,644
5,899
5,238
4,650
4,129
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
4,850
4,850
4,850
4,850
4,850
4,850
4,850
4,850
4,850
4,850
4,850
4,850
See footnotes on Page 85.
78
1,850
2,595
6,638
10,234
14,256
14,256
8,895
1970
14,256
8,895
1967
(Acres)
0
28
4,589
6,672
1,650
1,650
1,650
1,650
1,650
1,650
1,650
1,650
1,650
1,650
1,650
1,650
43,351
48,846
54,995
61,943
69,765
78,578
88,501
99,637
112,259
126,434
142,397
149,688
792
1,906
3,188
4,622
6,232
8,039
10,080
16,756
28,119
40,801
50,007
54,173
(Acre-Feet)
44,143
50,752
58,183
66,565
75,997
86,617
98,581
116,429
140,378
167,235
192,404
203,861
Pro ected Adjustments on Farms in Size Grou. II to Changin Land and Water Availability, SRP.
Cotton
Alfalfa Hay
Barley-..
Idle
Water Supply Sources
Total
Yeara Skip-Row 4x4 b and PastureC
Ae Sorghum3 Land B 1 Projecttm Project Pump' Private Pump° Water Use
Table 20.
12,576
12,576
12,576
4,782
3,303
2,562
1,904
1,321
803
7,112
7,112
7,112
7,112
7,112
7,112
6,601
5,861
5,204
4,620
4,102
3,642
Yeara
1967
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
4,250
4,250
4,250
4,250
4,250
4,250
4,250
4,250
4,250
4,250
4,250
4,250
(Acres)
Ae
See footnotes on Page 85.
343
7,598
10,776
Alfalfa Hay
and Pasturec
0
1,767
2,000
2,000
0
3,790
5,628
Barley
450
450
450
450
450
450
450
450
450
2,217
6,240
8,078
Land B1
Idle
38,244
43,074
48,513
54,642
61,544
69,317
78,071
87,927
99,029
111,534
125,615
132,048
3,892
4,887
6,005
7,263
8,684
10,287
14,449
23,348
33,371
38,195
34,288
32,450
(Acre-Feet)
42,136
47,961
54,518
61,905
70,228
79,604
92,520
111,275
132,400
149,729
159,903
164,498
Water Supply Sources
Project Private
Total
Pumpn
Pump°
Water Use
Projecttm
Projected Adjustments on Farms in Size Group III to Changing Land and Water Availability,
SRP.
Cotton
Skip-Row
4x4b
Table 21.
3,171
2,540
5,086
5,086
5,086
5,086
5,086
5,086
5,086
5,086
4,541
4,032
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
2,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
(Acres)
See footnotes on Page 85.
2,031
5,109
7,291
9,750
12,518
13,728
13,728
13,728
13,728
5,086
1970
13,728
5,086
1967
Yeara
0
1,907
5,418
9,372
10,296
10,296
0
3,530
4,988
0
1,907
5,418
9,372
10,296
10,296
42,332
47,677
53,700
60,483
68,120
76,727
86,451
97,321
109,613
123,462
139,041
144,144
5,386
6,485
7,935
14,059
20,954
28,724
37,471
39,388
35,876
31,922
38,058
39,790
(Acre-Feet)
47,718
54,168
61,635
74,542
89,074
105,451
123,886
136,709
145,489
155,384
177,099
183,934
Projected Adjustments on Farms in Size Group IV to Changing Land and Water Availability, SRP.
Cotton
Water Supply Sources
Total
Skipjow Alfalfa Hay
Sugarf
Barley-.
Idle
Project Private Water
h
4x4
and PastureC Beets
Barley
Sorghum
Land B
Projecttm
Pump'1
Pump°
Use
Table 22.
2,457
2,457
2,457
2,457
2,457
2,457
2,457
2,457
2,457
2,457
2,457
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
0
2,500
2,500
2,500
2,500
2,500
See footnotes on Page 85.
2,457
a
1,300
1,300
1,300
1,300
1,300
1,300
1,300
1,300
1,300
1,300
1,300
1,300
(Acres)
.
0
286
286
2,786
2,786
2,786
2,786
2,786
2,786
2,786
286
286
286
4,086
4,086
4,086
4,086
4,086
4,086
4,086
1,586
1,586
1,586
1,586
1,586
15,218
15,218
15,218
15,218
15,218
15,218
2,874
2,874
2,874
2,874
2,874
2,874
2,874
8,699
21,043
15,218
8,699
21,043
8,699
11,485
21,615
21,043
11,485
21,615
(Acre-Feet)
Projected Adjustments on Farms in Size Group I to Increasing Water Costs, RWCD.
Cotton
Wheat
Skip-Row Alfalfa Hay
Idle
Idle
Water Supply
and
Early
1
k
4x4b
Land B
Land A
and Pasture
Barley
Sorghum
PrivateP NonprivateP
1967
Year
Table 23.
18,092
18,092
18,092
18,092
18,092
18,092
18,092
29,742
29,742
29,742
33,100
33,100
Use
Total
Water
2,390
2,390
4,905
4,905
4,905
4,905
4,905
4,905
4,905
4,905
1985
1990
1995
2000
2005
2010
2015
2020
See footnotes on Page 85.
0
4,190
4,190
4,905
1980
4,190
0
4,905
1975
2,390
2,390
2,390
2,390
2,390
2,390
2,390
2,390
2,390
5,000
4,905
2,390
1970
5,000
4,905
1967
(Acres)
0
2,200
2,200
2,200
2,200
2,200
2,200
1,390
1,390
6,390
6,390
6,390
6,390
4,190
4,190
4,190
6,550
6,550
6,550
6,550
6,550
6,550
6,550
2,360
2,360
2,360
1,550
1,550
30,352
30,352
30,352
30,352
33,652
33,652
33,652
43,414
43,414
43,414
44,086
44,086
8,938
8,938
8,938
8,938
11,139
11,139
11,139
25,091
25,091
25,091
26,978
26,978
(Acre-Feet)
Table 24. Projected Adjustments on Farms in Size Group II to Increasing Water Costs, RWCD.
Cotton
Skip-Row Alfalfa Hay
Alfalfa
Idle
Idle,1
Water Supply
a
h
1
Ae
Hayd
and PastureC
Year
Barley
Land A
Land B
ProrateP NonprorateP
39,290
39,290
39,290
39,290
44,791
44,791
44,791
68,505
68,505
68,505
71,064
71,064
Total
Water
Use
Water price charges
Barley uses first half land A and sorghum uses
1.
Cotton, alfalfa hay and pasture, alfalfa hay, sugar beets, barley-sorghum and dry onions
use land A and B. Barley, early sorghum, wheat, spring lettuce and carrots use only land A.
Late
sorghum, fall lettuce and potatoes use only land B.
Early sorghum uses first half land A.
Barley and sorghum are double-cropped.
second half land B.
Includes 1,100 acres of wheat and 200 acres of barley.
Barley is produced on Size Groups I, III, IV in the SRP and Size Group II in the RWCD.
Wheat is produced on Size Group III and those listed in footnote i below.
Sugar beets are produced on Size Group IV and those listed in footnote e above.
Includes 1,500 acres of wheat; 1,000 acres (Tables 20 and 21) and 850 acres (Table 24) of
sugar beets; 350 acres (Table 20), 400 acres (Table 21) and 750 acres (Table 24) of spring lettuce;
550 acres (Tables 20 and 21) and 390 acres (Table 24) of fall lettuce; 250 acres (Table 20), 400 acres
(Table 21), and 200 acres (Table 24) of potatoes; 600 acres (Table 20), 900 acres (Table 21), and 200
acres (Table 24) of dry onions; and 600 acres (Table 21) of carrots.
Alfalfa hay produces 4.5 tons of hay in the RWCD.
Alfalfa hay produces 6.5 tons of hay and 25 days of pasture in the SRP and 4.5 tons of hay
and 25 days of pasture in the RWCD.
Cotton, skip-row, 4x4, occupies two acres of land for each acre of cotton listed.
Land availability in total and by size group by years is in Table 18.
by years are in Table 17.
Footnotes for Projection Tables 19 through 24.
period.
Water supplied by the RWCD is divided into two delivery periods; the prorate period is in
effect from March through September. The nonprorate period refers to the remainder of the production
Size Groups II, III and IV have two, three and six private wells, respectively.
SRP lands have an average of two acre-feet of project pump water available per acre.
The SRP supplies two acre-feet of assessment water per acre and 1.0 acre-foot of stored
and developed water per acre and an average of .5 acre-feet of normal flow water per acre.
Footnotes for Projection Tables 19 through 24, (Continued).
87
alfalfa hay and pasture enterprises.
Double-cropped barley-sorghum
is excluded from the farms represented by this model in the fourth
iteration representing the twentieth year hence; whereas,
the alfalfa
hay and pasture combination continues through the fiftieth year, though
at decreasing acreage levels.
Adjustment in SRP farm model Size Group
III occurs in the barley enterprise, which disappears in the third
iteration (the fifteenth year hence), wheat which is excluded in the
fourth iteration (the twentieth year), and alfalfa hay and pasture,
which remains in the model but in continually decreasing acreage amounts.
SRP Farm Size Group IV enterprise adjustments take place in barley-sorghum
acreage, which drops out of these farms in the third iteration (the
fifteenth year); barley, which disappears in the sixth iteration (the
thirtieth year); and alfalfa hay and pasture, which steadily declines
through the 53-year projection.
RWCD farm model Size Group I farms adjust their acreages in
early planted sorghum and alfalfa hay and pasture.
Sorghum drops out
of the optimum mix in iteration three (the fifteenth year) and alfalfa
hay and pasture in iteration six (the thirtieth year).
Adjustments in
model Group II farms occur in acreages of alfalfa hay, alfalfa hay and
pasture, and barley.
Alfalfa hay and pasture remains on these farms for
two iterations (10 years).
In the third iteration (at 15 years hence)
alfalfa hay enters and barley acreage increases.
Alfalfa hay remains
through the fifth iteration (25 years), while barley acreage continues
constant through the eighth iteration (40 years hence), at which time
it falls to zero.
88
Aggregate farm model adjustments to changing land and water
availability in the SRP and increasing water costs in the RWCD, as
generated by the linear programming projection, are presented in
Tables 25 and 26.
These tables are, with the exception of preliminary
1968 reported acreages, the summation of progralLuuing projections of the
individual farm model groups from each irrigation district for each time
period from year 1967 to 2020.
Reported 1968 crop acreages are taken
directly from irrigation district preliminary crop reports (SRP, 19621968 and RWCD, 1963-1968a).
The 1968 reported acreages differ from
those generated by the linear programming model for the 1967 crop year
for several reasons discussed below.
The 1968 reported cotton acreage varies from the 1967 projected
acreage due to ASCS cotton program changes between 1967 and 1968.
(The
program has changed again for 1969 as a result of which it is expected
that planted cotton acreage will further increase.)
A further source
of variance between actual cotton acreage reported in 1968 and cotton
acreage "predicted" by the model for 1967 is that in the model prediction
cotton is grown entirely in a 4x4 skip-row pattern.
ASCS reporting
procedure does not distinguish between solid and skip-row planted acreage
for the study area.
However, it is known that not all acreage was
actually planted in 1968 in a 4x4 skip-row pattern.
Possible reasons for
the difference between 1968 reported and 1967 model predicted acreage
cotton planting patterns are (1) that farm operators have a noneconomic
preference for using land rather than allowing it to lie idle in skipped
rows, (2) that farm operators are not aware of the profitability of 4x4
skip-row planted cotton over solid planted cotton or, (3) that farm
4,000
4,000
26,047
25,017
22,876
21,058
19,268
17,744
15,713
13,958
1985
1990
1995
2000
2005
2010
2015
2020
Source:
4,000
26,171
1980
4,000
4,000
4,000
4,000
4,000
5,600
5,600
5,600
5,600
5,600
5,600
5,600
5,600
5,600
5,600
5,600
(1,948)
5,600
3,488
5,215
6,981
10,161
13,928
19,371
23,977
30,081
37,641
43,871
46,039
(45,392)
47,149
Land B refers to land used from June to December.
Tables 19 through 22.
a.
4,000
26,171
1975
4,000
4,000
26,171
1970
4,000
(3,428)
26,171
(Acres)
0
28
8,119
(9,619)
11,660
1,500
9,198
1,118
1,271
1,302
1,598
1,801
2,885
2,299
1,500
1,500
1,500
1,500
1,500
1,500
1,500
1,500
3,267
14,785
4,479
3,500
(3,626)
3,500
27,785
(27,895)
33,164
Projected Adjustments in Agriculture to Changing Land and Water Availability, SRP.
Cotton
Sugar
Vege-.
Alfalfa Hay
Skip-Row 4x4
Beets
tables
Barley
and Pasture
Sorghum
Wheat
(28,912)
1968
(Reported)
1967
Year
Table 25.
Idle
3,218
3,371
3,402
3,698
3,901
4,985
4,399
6,579
13,065
18,661
23,694
25,604
Land Ba
850
850
7,362
7,362
7,362
7,362
7,362
7,362
7,362
7,362
7,362
1980
1985
1990
1995
2000
2005
2010
2015
2020
December.
850
7,362
1975
1,540
1,540
1,540
1,540
1,540
1,540
1,540
1,540
1,540
1,540
1,540
(886)
1,540
1,100
1,100
1,100
1,100
3,300
3,300
3,300
3,300
200
200
200
200
200
200
200
200
200
200
200
(257)
200
0
286
(2,002)
286
0
4,190
4,190
4,190
286
286
286
9,176
9,176
9,176
9,176
6,976
6,976
10,636
10,636
10,636
10,636
10,636
10,636
10,636
3,946
3,946
3,946
3,136
3,136
Bb
Idle Land
6,976
A
Land A refers to land used from December to June and land B to land used from June to
0
2,500
3,300
3,300
2,500
2,500
2,490
(3,249)
2,490
7,500
(7,958)
7,500
Taken from Tables 23 through 24.
850
850
850
850
850
850
850
850
7,362
1970
850
(849)
7,362
(Acres)
Projected Adjustments in Agriculture to Increasing Water Costs, RWCD.a
Cotton
Sugar VegeAlfalfa Hay
Alfalfa
Wheat Sorghum
Hay
Skip-Row 4x4 Beets tables and Pasture Barley
(8,754)
1968
(Reported)
1967
Year
Table 26.
91
operators would rather plant a small grain crop, such as barley or sorghum,
on the acres that would be skipped if skip-row cotton were planted due
to expectations of exceptionally high yields and/or prices for that crop.
The optimum cropping solution, however, indicates that net revenue is
increased if 4x4 skip-row rather than solid planted cotton is grown.
It is presumed, therefore, that 4x4 skip-row planting will increase with
increasing experience, knowledge, and economic pressures.
Although
available evidence indicates that the present (1968-1969) relaxation
on cotton planting restraints within allotted acres will cause further
increase in cotton planted acres compared to that predicted by the
model for 1967 and illuLlediately succeeding years, this is expected to be
a temporary phenomenon that will, in the long run, be again restrained
due to cotton surpluses expected to result from the increases in planted
acreage in 1968 and 1969.
Thus, projections for the long pull are made
in this study at the 1967 restrained level of acreage.
Sugar beet acreage in 1968 and that predicted by the model for
1967 are comparable in the RWCD.
For the SRP, sugar beet acreage reported
in 1968 and 1967 model predicted acreages differ.
The reason for this
difference may be the extremely low yields experienced by some SRP growers
in 1967 and the resultant discontinuation of sugar beet acreages by them.
Current indications are, however, that sugar beet acreage in the SRP is
increasing, probably as a result of increasing experience with the crop
and more favorable producing conditions, and will approach that predicted
for the longer run by the model.
Thus, we expect the current discrepancy
in acreages to be a temporary phenomenon and accept the model acreage
predictions for the long run.
92
Vegetable acreage reported in 1968 for both districts does not
include fall planted acreage (data were not available) and, hence, is
lower than 1967 acreage predicted by the model.
Acreages of alfalfa hay
and pasture and other field crops reported in 1968 correspond quite well
with acreages of these crops predicted by the model for the 1967 crop year.
A composite of model acreages of all crops in both the SRP and
RWCD is presented in Table 27.
Cropland and Water Use
Lands A and B, the two types specified to coincide with growing
periods of short season crops, are used to various degrees in each of
the six farm models.
Land A refers to first-half land use (roughly
December to June) and land B to second-half land use (roughly June to
December).
Some crops use land during either the first or second half
of the growing season while others use land during both periods.
SRP land A is fully utilized at all times on all farms over the
projected time period.
Land B, however, as indicated in Tables 19
through 22, is idle in varying acreages in all SRP farm models.
SRP Group I model farms permit
land B to lie idle because there
is no paying alternative enterprise available to them to follow barley
which occupies land A.
Late sorghum is the only alternative; however,
its net return per unit of water is such that project pump water, at
$7.50 per acre-foot, cannot be used to produce it profitably.
Idle
land B in Group II model farms results from the use of land A for wheat
and vegetable production, while no economically feasible alternative using
$7.50 per acre-foot project pump water is available for the profitable
use of the land in the second time period.
4,850
4,850
33,533
33,409
32,379
30,238
28,420
26,630
25,106
23,075
21,320
1980
1985
1990
1995
2000
2005
2010
2015
2020
December.
a.
4,850
33,533
1975
7,140
7,140
7,140
7,140
7,140
7,140
7,140
7,140
7,140
7,140
7,140
7,140
3,488
5,215
6,981
10,161
13,928
19,371
23,977
36,771
44,331
50,561
53,539
54,649
2,228
2,371
2,402
2,698
5,101
6,185
5,599
7,779
12,498
18,057
22,156
23,994
(Acres)
0
28
8,119
11,660
0
286
286
1,700
1,700
1,700
1,700
1,700
1,700
1,700
1,700
1,700
3,467
3,700
3,700
9,176
9,176
9,176
9,176
6,976
6,976
6,976
286
286
286
13,859
14,007
14,038
14,334
14,537
15,621
15,035
10,525
17,011
22,607
26,830
28,740
Land A refers to land used from December to June and land B to land used from June to
4,850
4,850
4,850
4,850
4,850
4,850
4,850
4,850
33,533
1970
4,850
33,533
1967
Year
Projected Adjustments in Agriculture toChanging Land and Water Availability and Increasing
Water Costs, SRP and RWCD.
Cotton
Sugar
VegeAlfalfa Hay
BarleyEarly
Idle Land
Aa
Ba
Beets
Skip-Row 4x4
tables
Sorghum
and Pasture
Barley
Sorghum
Wheat
Table 27.
94
Nonuse of land B by Group III model farms results initially from
using land A for vegetables, wheat and barley production, with no following
profitable use for land B.
As barley and wheat drop from the optimum
solutions and as total cropland availability declines, both remaining
land A which was being used and remaining idle land B are brought into
use to offset the decline in total cropland acreage.
Group IV model farms
let land B be idle because land A is used for barley production and there
is no alternative crop that can use land B profitably due to the cost of
using private pump or project pump water.
Lands A and B in the RWCD are both idle, as shown in Tables 23 and
24, at various times throughout the projection period.
In Group I farms,
land B remains idle because of alternatives unable to profitably use
$8.50 per acre-foot project water.
of $9.69 per acre-foot in 1975.
Land A becomes idle at water costs
Idle lands A and B increase over the
projection period as water costs per acre-foot increase.
Idle land B in RWCD Group II farms occurs at water costs of
$8.50 per acre-foot in 1967.
This results from barley and vegetable
use of land A, with no profitable alternatives available for land B.
At per acre-foot water costs of $11.51 in 1990, idle land A appears
because alfalfa drops out of the optimum solution.
Total projected acreages of idle land by project and by study
area are presented in Tables 25, 26 and 27.
Total water use by agriculture in the SRP is composed of that
supplied by the project and that which is pumped by farm operators.
Project supplied water is made up of surface runoff and water pumped
by the project.
Water use by agriculture in the RWCD combines surface
95
flow from the SRP system (Chapter II, Roosevelt Water Conservation
District) and groundwater pumped by the project.
Although private wells
are located on farms in Size Group II in this project, they are typically
not needed since project supplied water is sufficient to meet all demands.
Projected use of water in agriculture in the SRP is a function
of its cost and the amount of available land on which to use it.
As
total land availability declines, so also does the total quantity of
low cost, project supplied surface water.
However, the quantity of this
low cost water used per land acre remains constant and, in no case, is
production restricted by a physical lack of water.
The variable that affects water use in the SRP is the price of
pumped water, both private and project.
All farm size models, except
Model I, have access to privately pumped water; however, its use is
discontinued when it becomes more costly to pump water from these private
veils than to obtain water from project pump sources at $7.50 per acrefoot.
As shown in Tables 20 through 22, this occurs between the second
and third iteration (10 to 15 years hence).
Succeeding iterations
throughout the entire 53-year projection period employ only water supplied
by the project under the assessment, from normal flow and from stored
and developed rights, plus varying quantities of project pump water,
the
prices for which as explained earlier herein, are assumed to remain constant over time.
Water use by farm size model by source for each future
time period is presented in Tables 19 through 22.
Water use on farm models in the RWCD is shown in Tables 23 and
24.
Since land acreage is unchanging over the projection period, the
changes in water use over time are strictly a function of its increasing
96
price due to the steadily increasing pumping lift.
All water is assumed
to be supplied from project sources, even though private wells are located
on some Model II farms.
As explained above, due to private pumping
costs being assumed herein to be higher than project pumping costs from
the same depths, no water is produced from these private wells.
Total projected water use by district, per acre, and for the
total study area is presented in Table 28.
Water use on projected
acreage decreases substantially over time.
SRP total agricultural water
use decreases 76 percent and RWCD use decreases 45 percent over the
projection period.
During this same time period, cropped acreage will
decline by 71 percent in the SRP and by 50 percent in the RWCD.
Water
use per acre of available cropland declines by 15 percent in the SRP and
by 46 percent in the
RWCD
over the projection period due to increase in
areas of idle cropland.
Net Revenue Changes
Projected net revenue changes by farm model size group by project,
and in total for the study area are presented in Table 29.
Changes over
time in SRP net revenue are due to increasing water costs and decreasing
land availability.
Increasing water costs affect net revenue only until
privately pumped water reaches $7.50 per acre-foot in 1971, at which time
project supplied pump water will be used in place of private pump water,
as shown in Tables 19 through 22.
The effect of decreasing cropland
availability accounts for all net revenue declines in the SRP after 1971.
Net revenue changes over time in the
RWCD
are in response to the increasing
cost of obtaining water throughout the projection period.
610,434
476,735
416,430
136,988
121,630
107,995
95,888
85,139
75,593
67,116
59,590
52,907
46,974
41,707
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
156,621
178,361
203,036
235,338
3.8
3.8
3.8
3.9
4.0
4.1
312,678
271,706
4.2
4.3
4.4
4.5
4.5
4.5
361,173
543,403
640,575
144,000
27,000
27,000
27,000
27,000
27,000,
27,000
27,000
27,000
27,000
27,000
27,000
27,000
(Acre-Feet)
57,382
57,382
57,382
57,382
62,883
62,883
62,883
98,247
98,247
98,247
104,164
104,164
2.1
2.1
2.1
2.1
2.3
2.3
2.3
3.6
3.6
3.6
3.9
3.9
Projected Water Use by District, per Acre by District and by Study Area.
SRP
RWCD
Total
Water Use
Total
Water Use
Acreage
Water Use
per Acre
Acreage
Water Use
per Acre
1967
Year
Table 28.
214,003
235,743
260,418
292,720
334,589
375,561
424,056
514,677
574,982
641,650
714,598
745,893
Total
I
1,813
1,774
1,688
1,610
1,517
1,345
1,143
1,062
943
850
742
660
1967
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
3,326
3,125
2,946.
2,812
2,622
3,553
3,266
3,026
3,809
1,720
1,929
2,160
2,297
2,451
2,625
4,096
3,537
3,842
2,820
2,984
3,129
3,292
3,467
3,556
4,355
4,530
4,422
4,185
4,728
4,938
4,711
4,558
5,102
5,201
4,886
5,012
437
447
456
465
476
487
497
512
530
540
569
558
1,511
1,534
1,558
1,582
1,607
1,635
1,662
1,694
1,733
1,755
1,816
1,858
7,948
8,608
9,362
10,059
10,858
11,706
12,706
13,454
14,025
14,628
15,228
15,592
(Dollars in Thousands)
1,940
1,981
2,014
2,047
2,082
2,121
2,159
2,206
2,263
2,295
2,384
2,446
9,888
10,589
11,376
12,106
12,940
13,828
14,865
15,660
16,288
16,923
17,612
18,038
Projected Aggregate Net Revenue over Variable Production Costs by Farm Size Gro,ip,
Irrigation District and Study Area.
Aggregate Net Revenue by Farm Size Group
Net Revenue by
SRP
Total Study Area
RWCD
Irrigation District
II
RWCD
III
IV
I
SRP
Net Revenue
II
Year
Table 29.
99
Total revenue over variable production costs in both districts
is derived primarily from cotton, sugar beets, and vegetables.
half of all net revenue was derived from these crops in 1967.
Over
Throughout
the projection period, as alfalfa and small grain crops drop out of
optimum farm operations, cotton, sugar beets and vegetables provide a
steadily increasing percentage of the total net revenue.
As the total acres of crops decreases from year to year, total
gross revenue and production costs will decrease in lesser proportion
than acreage because crops that produce low net values per acre and that
incur low production costs per acre will be progressively eliminated.
A loss of revenue to agricultural factor suppliers and product handlers
will result.
This loss, however, will not be in proportion to acreage
changes, but will be in proportion to changes in factor needs and product
output represented by deleted crops.
Net revenue per year over variable production costs in the SRP
and RWCD will decline by approximately 50 and 21 percent, respectively,
between 1967 and 2020.
However, cropped acreage will decline by 71 per-
cent in the SRP and by 50 percent in the RWCD during the same period.
Over this projection period, SRP and RWCD water use will change by 76
and 45 percent, respectively.
In tabular form, the above percentages
over the 53-year projection period are as follows:
Net Revenue
Decrease
Cropped Acreage
Decrease
Water Use
Decrease
(Percent).
SRP
50
71
76
RWCD
21
50
45
100
Figures 3 and 4 show in graphic form net revenue and water use
projections for the SRP and RWCD.
These figures both contain dual hori-
zontal axes which in each figure relates an important independent variable
to time over the projection period.
In the SRP, variations in land
availability over time are determined by competition for its use by the
urban-industrial sector; in the RWCD, variation in water cost per acrefoot is determined by the increasing depth of the groundwater table.
Net
revenues are scaled on the left-hand axis and acre-feet of water on the
right-hand axis of these figures.
They portray the projected relative
changes in net revenue and water use over time for each district.
Both net revenue and agricultural water use in the SRP decline
primarily as a result of declining land availability.
cost is of minor consequence.
rapidly than water use.
Increasing water
Net revenue, however, decreases less
This is a reflection of the increasing propor-
tion of crops in the enterprise mix on the declining land area that
produces a high value per acre-foot of water used.
In the RWCD, revenue and water use decline wholly as a result
of increasing water costs since available acreage is constant.
As in
the SRP, water use changes more rapidly than net revenue due to the
increasing proportion of high net return crops in the enterprise mix that
makes use of the increasingly costly water.
Firm Numbers
Since this analysis assumes no transfer of land among farm size
groups (Chapter IV, Land Availability) and since land acreage in agriculture is projected to decrease continuously in all size groups in the
SRP, total
numbers of farm units will decrease from those presented in
101
$16
14
12
U)
Net Revenue
10
C
0
550
C
U)
C
C
450 0
U)
0
I-
Water Use
C
350
44
a,
U
250
ISO
Acres
0
144,000
137,000
1970
1967
122,000
1975
108,000
1980
96,000
1985
85,000
76,000
67,000
60,000
53000
47,000
42,000
1990
1995
2000
2005
2010
2015
2020
Time in Years
FIgure
3.
Projected
Water Use and Net Revenues over Variable Production Costs1 SRP.
102
2.5
110
2.3
Net
Revenue
U)
C
.9
2.1
90
C
1.9
Water
Use
C
0)
>
0)
70
4-
z0)
50
Dollars per Acre-Foot
8.50
9.09
9.69
10.30
10.91
1967
1970
'975
1980
1985
11.51
1211
12.72
13.33
1990
'995
2000
2005
Time
Figure 4.
Projected
in
Years
Water Use and Net Revenues over Variable Production Costs, RWCD.
13.93
4.54
15.14
2010
2015
2020
103
Table 4 of Chapter III.
Projected decreases in farm numbers in the SRP
are presented in Table 30.
Table 30.
Projected Change in Farm Numbers by Farm Size Group, SRP,
1967 and 2020.
Farm Size Group
Year
I
II
III
(100 Acres)
(400 Acres)
(900 Acres)
223
106
42
23
394
65
31
12
7
115
IV
Total
(1,800 Acres)
From Table 4.
Year 2020 land acres divided by farm model size.
Agricultural acreage in the RWCD is not expected to change over
the projection period although cropped acreage will decline.
Farm numbers,
as shown in Table 5. will not change over time, only decreases in cropped
acreage per farm.
Land transfers between size groups are not projected
to take place since a large number of small units exist at the present
time; their primary source of revenue presently is cotton, and over the
projection period their cotton acreage remains constant.
Presumably, the
operators of these small farms consider their returns adequate in the
present as there is no clear indication that larger farm units are presently
absorb4ng them.
Thus, there is no reason within the postulated assumptions
of this study to assume land or entire farm transfers from small to larger
units will take place in the future.
Adjustments will take place only
in terms of cropped acres within the existing number of farm units.
As described in Chapter IV (Land Availability and Water Supply
Functions) it is assumed when making these projections that the proportion
of farms falling in the several size groups in each district will remain
104
constant throughout the projection period.
Because of conditions within
the SRP (primarily the relatively low and stable cost of available water),
this seems a reasonably safe assumption for that district.
However, in
the RWCD, because water cost is presently higher than in the SRP and
is expected to increase in cost throughout the projection period due to
a progressively falling water table, the assumption of a constant proportion of farms by size is questionable.
Earnings by small size farms
in the RWCD (Model Size I of 100 acres) were decidedly low in 1967 and
throughout the projection period will become progressively lower, even
negative, (see Table 31).
It is probable, therefore, that Model I farms
in the RWCD are now and will come under increasing economic pressure to
disappear and be incorporated into larger size farms.
It is even possible
that significant numbers of 900-acre (Model III) and 1,800-acre (Model IV)
farms will appear in this district though the analysis reported herein
does not provide for the presence of farms of such sizes throughout the
53-year projection period.
Thus, the assumption concerning farm size distributions in the
RWCD is probably overly restrictive on the ability of agriculture in that
district to make economically meaningful adjustments to increasing water
scarcity.
Thus, projections reported herein of declining aggregate net
revenue, changing enterprise combinations, declining water use, and
output are somewhat exaggerated in comparison to what will, in reality,
occur.
However, at most, these discrepancies will be modest.
For
example, net revenue in the district (see Page 98) is projected to
decline approximately $500,000, or by 21 percent over the 53-year
Farm Model
Acres
Farm Size
Group
400
900
1,800
II
III
IV
400
II
(4)
116,729
25,010
5,211
78,278
319,614
19,691
47,473
24,221
107,954
225,046
4,866
Costs
Fixedb
Annual
19,710
Gross
a
Returns
(3)
(6)
Net Return
to Land an
Management
41,276
6,531
155,043
123,831
47,286
8,128
16,266
1,320
76,765
76,358
23,065
3,262
(Dollars per Farm)
Net
Revenuec
(5)
(7)
5,836
981
15,980
11,252
5,397
985
Managemente
for
Allocation
Return to land or to water and land as the ultimate fixed factor.
Calculated as five percent of gross returns in column 3.
Column 5 minus column 4.
Revenue in each size group of Table 29 divided by number of farms in each group.
From Table 12.
(8)
10,430
340
60,785
65,106
17,668
2,277
Residual
Calculated from acres of crops in Tables 19 through 24 multiplied by gross returns per
acre of Table 11.
100
I
Roosevelt Water
Conservation District
100
I
Salt River Project
(2)
Gross Returns, Fixed Costs and Net Revenue per Farm and Its Allocation, 1967.
(1)
Table 31.
0
Ui
f
106
projection period.
Even if all the Model I size farms were to disappear
and farms in the larger Size groups were to absorb all the Model I size
cropland, aggregate net revenues, water use, and output would still
decrease, though more slowly due to the somewhat greater efficiency
with which these larger farms would be able to use the acreage absorbed
from the smaller farms.
Though the decreases in the rates of decline
thus obtained might appear significant from the standpoint of the RWCD,
as these projections are aggregated with those developed for other
irrigated areas to assess statewide impacts of water scarcity, the discrepancies in the RWCD projection rapidly become insignificant.
In the
absence, therefore, of any objectively valid basis for incorporating in
the analysis a prograiuuied rate of transfer of smaller into larger sized
farms and because of the minor importance of the modified declines thus
derived when they are aggregated into the larger objectives of the total
study of which this is but one part, the restrictive assumption on farm
size transfer in the RWCD is allowed to stand.
It is important to remember, however, that in reference to the
RWCD specifically, appropriate adjustments made by farm managers will
soften the economic impact of increasing water scarcity and the declines
in net revenue, water use, and output will not be as large as projected
herein.
Allotments
Based on the need for a rotation for agronomic purposes, limited
acreageS of cotton, alfalfa, barley and sorghum as percentages of total
cropland acres were placed on the basic models.4
4.
See Chapter IV, Restrictions.
Sugar beets, wheat and
107
vegetable acreage limits were assumed to remain at originally specified
levels throughout the projection period.
Cotton acreage in the SRP is projected to decrease from 26,171
acres at the outset of the projection period to 13,958 acres at the end
of the period 53 years later.
In all farm size models, the percentage
of cropland employed in Cotton production is allowed to increase until
it reaches one-third of the model's acreage.
At and beyond this point,
cotton acreage in excess of one-third of the model's total acreage must
be disposed of under the assumptions of this study in order to maintain
a rotational balance among crops for agronomic reasons.
Cotton acreage
not planted in the SRP is assumed to be transferred to other agricultural
areas.
These allotments may be used in other areas of the state by their
original owners on an operation outside the SRP or they may be sold to
other operations outside the SRP, but within the county.
It is assumed
herein that ample opportunity for such cotton allotment transfers will
exist throughout the projection period.
RWCD cotton allotment acreage is assumed to remain constant at
1967 levels throughout the projection period.
Since in 1967, cotton
acreage is less than one-third of available croplarid and no change in
cropland acres is assumed, the total cotton acreage remains constant.
Cotton acreage does, however, occupy an ever
increasing proportion of
the land cropped as alternative crops drop from optimum solutions as
water costs increase over the projection period.
Total Costs and Net
Returns per Farm
A summary of costs and returns for each farm size model in each
district for 1967 is presented in Table 31.
Gross returns to each farm
108
are shown in Column 3.
Table 4 of Chapter III.
Annual fixed costs in Column 4 are taken from
Net returns in Column 5 are obtained from
Table 29.
Net return to land and management is the difference between gross
returns and all costs, both fixed and variable.
Net revenue figures of
Column 5 are exclusive of variable production costs.
Net revenue, less
fixed costs of Column 4, provide the residual return to land and management shown in Column 6.
The control and guaranty functions are assumed separable
although in many instances, especially on the smaller size farms, they
are performed by the same individual.
On large farms the control function
is more typically performed by hired managers responsible to the farm
owners who fulfill the guaranty function.
Return to the control function,
or management, is calculated as five percent of gross returns (Stults,
1968:50).
This is shown in Column 7 of Table 31.
Net return to land and/or rights to water is presented in
Column 8 of Table 31 as a residual return.
Since the right to use water
is associated with the control of land, and since land has no intensive
agricultural value without water, residual returns may more properly be
allocated to water rather than land.
Agricultural Demand for
Irrigation Water
Figures 5 and 6 present segmented demand functions for irrigation
water for each of the farm size models as of 1967.
The breaking points
of these discontinuous functions represent quantities and prices at which
water use will change among enterprise combinations.
The horizontal
109
250
240
60
50
40
30
4.-
U)
0
20
lO
l00- Acre Model
1800- Acre Model
900-Acre Model
L 400-Acre Model
1
0
1Q00
2000
3000
Quantity
Figure
5.
Individual
5000
4000
in
6000
Acre - Feet
Model Form Demands for Irrigation Water, SRP, 1967.
7000
8000
9000
10000
110
50
40
30
4U,
00 20
..-_-40Q- Acre Model
l0
100 - Acre
Model
1-i
0
200
400
1
600
800
Quontity
Figure 6.
Individual
1200
1000
in Acre- Feet
Model Farm Demands for Irrigation Water, RWCD
,
1967.
1400
1600
1800
2000
111
portions of these functions over a range of quantities indicate an
expansion of water inputs to a single enterprise.
All values for water above $56.75 per acre-foot result from its
use in vegetable activities.
Vegetables are grown only on SRP farms
in Size Groups II and III and
RWCD
farms in Size Group II.
All values
for water between $56.75 and $30.26 per acre-foot result from its use
in cotton production.
Sugar beet production demands water on SRP farm
Size Groups II, III, and IV and
RWCD
farm Size Group II at water values
between $30.26 and $21.90 per acre-foot.
Alfalfa competes for water in
all farm models at water costs between $15.42 and $9.38 per acre-foot.
Barley can compete for water at water values between $14.66 and $11.18
per acre-foot.
Wheat becomes a competitor for water at costs between
$13.93 and $13.08 per acre-foot.
Early planted grain sorghum can afford
to use water at a range of water values between $11.23 and $1.36 per acrefoot.
Late planted sorghum and barley-sorghum double-cropped become
effective demanders for water at water costs between $7.38 and $1.36.
Figures 7 and 8 show the aggregate quantity of water demanded
for irrigation at water costs between zero and $247.99 per acre-foot
in the SRP and RWCD, respectively.
Accompanying Tables 32 and 33 show
the water quantity and cost data from which the individual farm model
and aggregate irrigation district water demand functions are constructed.
In the SRP, at water costs of $15.42 per acre-foot and below,
relatively large increases in water use occur, as shown in Figure 7.
At this cost of water and below, crops requiring relatively large
quantities of water per unit of net revenue produced enter the optimum
solutions.
At prices above $15.42 per acre-foot only vegetables, sugar
112
250
240
65
60
Aggregate Demands
50
II
II
II
II
I
I
I
I
I
I
I
I
I
4-
0
0
IL
p
I
I
I
I
40
U,
I
126,413 Acre-Feet of
U
I
I
I
I
I
I
0I47 Acre- Feet of Project
I
I
Pump Water at
i1i
7. 50 per Acre-
Foot
I
I
I
I
I
Private Pump Water
a,
at
644 per Acre -
30
I
I
I
I
288,000 Acre-Feet of Avoilable
Foot
U,
0
i
C-)
I
I
L'
I
288,000 Acre-Feet of Project
l0
Water at
0 per Acre - Foot
I
I
l
Water at
200 per Acre- Foot
100,000
II
I
III
300,000
400,000
500,000
60D,000
Quantity in Acre - Feet
Figure
7.
Project Pump Water at
750
per Acre- Foot
ii
216,000 Acre - Feet of Project
I
200000
I
II
II
II
I
20
I'
Aggregate Agricultural Demand for and Supply of Irrigation Water, All Farms, SRP, 1967
I
Equilibrium
L
700,000
Point
'Aggregate Supply
800,000
900,000
113
60
50
4-
0
a,
0
4
40
a,
a.
4-
Aggregate
0
Demand
U,
C-)
30
20
Equilibrium Point
l0
Aggregate
Supply
20,000
40,000
60,000
80,000
Quantity
Figure 8
100,000
120,000
140,000
in AcreFeet
Aggregate Agricultural Demand for and Supply of Irrigation Water, All Farms, RWCD, 1967.
114
Table .32.
Price per
Acre-Foot
Demand for Irrigation Water at Various Prices by all Farms
in Each Farm Size Group and by the Aggregate of all Farms,
SRP, 1967.
Farm Size Group
I
II
III
(Dollars)
Total
IV
(Acre-Feet)
1.36
2.00
4.80
5.44
128,852
122,690
122,690
105,930
91,758
251,278
235,224
227,379
208,811
208,811
220,739
207,504
188,732
188,732
188,732
216,004
214,220
214,220
214,822
214,822
816,873
779,638
753,021
718,295
704,213
6.27
6.37
6.43
7.50
7.65
91,758
91,758
91,758
88,197
78,120
208,811
203,861
203,861
203,861
172,072
164,498
164,498
164,498
164,498
150,912
214,822
214,822
184,004
184,004
164,736
679,889
674,939
644,051
640,560
565,840
8.53
9.13
9.38
9.67
10.03
78,120
78,120
66,900
55,800
33,480
149,688
128,304
128,304
128,304
128,304
150,912
150,912
150,912
150,912
150,912
164,736
164,736
164,736
164,736
164,736
543,456
522,075
510,852
499,752
477,432
11.23
13.03
13.08
13.52
13.93
33,480
33,480
33,480
25,390
25,390
85,536
85,536
63,900
63,900
63,900
150,912
150,912
150,912
150,912
113,184
144,144
123,552
123,552
123,552
123,552
414,072
393,480
371,844
363,754
326,026
14.66
15.42
21.90
22.80
47.57
25,390
25,390
25,390
25,390
25,390
63,900
63,900
63,900
63,900
53,813
56,592
56,592
56,592
48,558
48,558
123,552
102,960
30,516
30,516
30,516
269,434
248,842
176,398
168,364
158,277
55.41
0
56.75
58.94
240.15
53,812
53,813
9,354
9,354
2,100
48,558
13,004
13,004
13,004
3,500
30,516
30,516
30,516
132,886
97,333
53,874
22,358
5,600
247.99
0
3,500
0
5575
0
3,500
115
Table 33.
Price per
Acre-Foot
Demand for Irrigation Water at Various Prices by all Farms
in Each Farm Size Group and by theAggregate of all Farms,
RWCD, 1967.
Farm Size Group
I
II
(Dollars)
Total
(Acre-Feet)
1.64
2.00
4.80
40,778
40,050
38,678
37,115
89,560
79,359
79,359
75,234
130,338
119,409
118,037
112,349
6.43
8.50
10.03
11.18
33,818
33,100
32,242
29,741
75,234
71,064
68,005
68,005
109,052
104,164
100,247
97,746
11.20
13.08
22.80
30.26
29,741
18,925
14,742
14,742
39,290
39,290
39,290
30,135
69,031
58,215
54,032
44,877
47.57
55.75
63.16
113.35
12,285
30,135
30,135
5,610
1;000
42,420
30,135
5,610
1,000
0
0
116
beets and cotton return sufficient revenue to command water on any SRP
farm size group.
used.
At this price for water, only 248,000 acre-feet are
At water prices between $15.42 and zero per acre-foot, rapidly
increasing quantities of water up to a total increase approximating 568,000
acre-feet of water are employed in growing alfalfa and small grain crops
in the SRP.
In the RWCD, as shown in Figure 8, relatively large increases
in water use occur at water costs of $11.20 per acre-foot and below.
At this water cost, alfalfa demands water.
At water costs above $11.20
only vegetables, cotton, sugar beets, and barley command water.
At costs
of $11.20 and below alfalfa, sorghum, and double-cropped barley-sorghum
use water.
Aggregate water supply conditions based on conditions that
existed in 1967 in the SRP and RWCD are also shown in Figures 7 and 8.
Aggregate water supply in the SRP is a composite of quantities available
at different prices.
The first 288,000 acre-feet are received after a
fixed assessment has been paid.
The variable cost of this water is zero.
A second aggregate quantity of 216,000 acre-feet can be obtained at a
cost of $2.00 per acre-foot.
The next most inexpensive source of water
is private pump water at $6.44 per acre-foot.
In 1967, 126,413 acre-feet
of private pump water were used on SRP Farm Size Groups II, III, and IV.
A final source of water is from project pumps.
A total agricultural supply
of 288,000 acre-feet of this water at $7.50 per acre-foot is available.
Of the total amount available, only 10,147 acre-feet were used in the
1967 model projection.
This was used exclusively on Farm Size Group I
farms which have no private wells.
117
The intersection of 1967 demand and supply functions, as shown
in Figure 7, predicts the use of 640,560 acre-feet of water at a marginal
water cost of $7.50 per acre-foot in the SRP.
The normal average cost
concept does not apply in the instance since water is supplied on a
marginal rather than an average cost basis.
Water supply conditions in the RWCD, based on conditions of 1967,
are shown in Figure 8.
In this district, there is but one price for
district water to all members.
foot.
In 1967, that price was $8.50 per acre-
At that price, 104,164 acre-feet were predicted to be used as
shown by the intersection of the supply and demand functions in Figure 8.
All water predicted by the analytical model to be used on the model farms
in 1967 was obtained from the district.
Though private wells, in reality,
exist on some farms in Farm Size Group II, they were not used in the
model projection to supply water for reasons explained above under Cropland and Water Use.
A comparison of actual water production in 1967 by the irrigation
districts and water use predicted by the analytical models for 1967 in
each district shows a high degree of comparability.
District water pro-
duction, losses, and deliveries to agricultural users are discussed
below.
Water use as projected by the 1967 analytical models is compared
to actual district water deliveries to agricultural users in 1967.
Water produced by the RWCD in 1967 totaled 126,144 acre-feet
(RWCD, 1963-l968b).
Of this amount, 90,215 acre-feet were pumped by the
project and the remaining 35,929 acre-feet were from surface sources
(see Chapter II, Roosevelt Water Conservation District).
Project records
show that 108,312 acre-feet were actually delivered to water users.
Thus,
118
17,832 acre-feet, or 14 percent, was system loss.
The model, in Table
28, predicts a 1967 RWCD water use by farmers of 104,164 acre-feet.
The
difference in these quantities (4,148 acre-feet) is remarkably small and
can, in fact, be accounted for by crops not included in the models such
as citrus and grapes, of which there are approximately 4,000 acres.
(These crops are also a source of demand for water supplies from private
pumps.)
The SRP produced 1,108,000 acre-feet of water for irrigation use
in 1967 (SRP, 1962-1967).
Of this amount, 709,000 acre-feet were from
surface sources and 395,000 acre-feet were pumped.
The relative surface
and groundwater percentages fluctuate from year to year; however, 1967
was a historically typical year (SRP, 1962-1967).
SRP irrigation deliveries for agricultural uses in 1967 totaled
541,167 acre-feet on 160,000 acres (SRP, 1968a).
Other project deliveries,
such as subdivision irrigation, domestic contracts, and other municipal
and industrial uses totaled 179,228 acre-feet.
Thus, total deliveries were 720,395 acre-feet.
Compared to
1,108,000 acre-feet produced, this leaves 377,605 acre-feet unaccounted
for (UAF) or system loss.
Smith (1968:92) estimates that approximately
15 percent (56,640 acre-feet) of this UAF water is actually delivered to
farm water users.
Adding 56,640 acre-feet to the 541,167 acre-feet
reported as delivered to farms gives an estimate of total water use as
being 597,807 acre-feet on 160,000 project acres.
Total water use in the SRP predicted for 1967 by the analytical
model used herein was 640,575 acre-feet on 144,000, as shown in Table 28.
Private pumps provided 126,368 acre-feet of this total amount.
The project
119
supplied the remainder, or 514,207 acre-feet.
Water in the amount of
597,807 acre-feet was estimated to have been actually delivered by the
SRP to 160,000 acres in 1967; the analysis reported herein predicted that
project supplied water in the amount of 514,207 acre-feet would be
delivered in that year to 144,000 acres.
The difference between the
actual and predicted figures is 83,600 acre-feet of project water available for use on 16,000 acres not included in the representative model
farms.
These acres were used for nonmodel crops in 1967, such as sugar
beet seed, fruits and nuts, garden crops, and pasture.
Average water use
per acre on these 16,000 cropped acres was approximately five acre-feet
per acre; thus, accounting for essentially all the discrepancy between
the actual and predicted water deliveries in the SRP.
Water Parameter Variations
This section explores sources of additional water supplies, the
uses that would be made of additional supplies at various prices, and
the net revenue these additional water supplies would generate if available for use in agriculture.
Demand for water supplies additional to
those now available, or foreseen as available at selected future times,
are projected.
This projected demand is for a supplemental or replacement
supply of water since additional supplies would be used only if available
at prices below those paid in 1967 or projected as being paid in selected
future years.
Additional Water Sources
Presently there are a number of additional sources of water being
developed.
area.
These are from sources within, as well as outside, the study
120
Surface water delivered to central Arizona via the Central Arizona
Project is expected to provide approximately 1,450,000 acre-feet of water
by 1975 (United States Congress, Senate 1967:29).
Quantities available
to the SRP and RWCD have not as yet been determined.
A second possible
source of additional surface water supplies is management of the watersheds of the Salt and Verde Rivers for increased runoff.
Additional
quantities of water from this source are known only on an experimental
basis; however, work is currently progressing on treatment practices
(Arizona Water Resources Committee, 1957-1968).
A third source of additional surface water is stream bank and
floodplain phreatophyte control.
Estimates of water loss due to evapo-
transpiration in the Salt River basin are approximately 55,000 acre-feet
annually.
The amount of water potentially available to water users asa
result of phreatophyte control is not known.
Water reclamation offers another source of increased supply.
Nonconsumptive uses of water by the metropolitan area within the SRP
produce large quantities of reclaimable water.
The ownership of this
water is not clear; however, regardless of its ownership status, its
availability will have an influence on irrigation water availability
and costs over time.
This will occur either through its direct use by
agriculture, by groundwater recharge, or indirectly by influencing the
water demands of the urban-industrial sector relative to those of the
agricultural sector.
Changes in water use technology within the agricultural sector
provides a further means whereby more water may effectively become
available.
Agricultural technicians are currently employed by the SRP
121
to act as advisors to water users (Smith, 1968:88) by providing information
relative to optimum water need.
Increased efficiency is constantly being
attained in water delivery systems in both the SRP (Smith, 1968:123) and
RWCD.
A decrease in water system loss means an increase in availability.
A continual canal, lateral and ditch-lining program is being carried on
by both the SRP and RWCD and by agricultural water users.
Substantial
increases in water availability are attainable as delivery efficiencies
are improved from the present approximately 70 percent in the SRP and
85 percent in the RWCD.
Values and Quantities of Additional Water
Water supplies in additionto those available in 1967 will be of
value to agriculture in the SRP and
RWCD
only if they are available at
costs such that they can be employed in growing crops of a relatively
low value per acre-foot of water used and are cheaper than presently
available supplies.
Figure 5 shows that for additional water supplies
to have been of value to agriculture in 1967 in the SRP they must have
been available at prices below $7.50 per acre-foot on Farm Size Group I
and below $6.44 per acre-foot on Farm Size Groups II, III and IV.
A
schedule of quantities of replacement and additional water projected by
this analysis to be used at various marginal water prices at selected
future years in the SRP is presented in Table 34.
At constant marginal
water prices, the quantity used will change over time because of the
declining availability of land.
As the cost of the marginal or highest
priced water in the SRP is decreased from $7.50 per acre-foot, the present and projected cost of marginal water available from present sources,
to a hypothetical $2.00 per acre-foot, which is the present cost of the
122
Table 34.
Estimated Time-Related Demand fo
Agriculture in the SRP and RWCD.
Replacement Water for
Selected Years
1967
1990
2020
Price
Range
(Dollars!
Acre-Foot)
District
15.14-Above
RWCD
0
15.13-13.08
RWCD
54,032
54,032
13.07-11.51
RWCD
0
54,032
54,032
11.50-11.20
RWCD
58,251
58,251
58,251
58,251
11.19-18.18
RWCD
69,031
69,031
69,031
69,031
11.17-10.03
RWCD
97,746
97,746
97,746
97,746
10.03- 8.50
RWCD
District
Total
District
Total
District
Total
(Acre-Feet)
0
SRP
100,247
100,247
0
0
100,247
8.49- 7.50
RWCD
SRP
104,164
104,164
104,164
0
62,000
10,070
104,164
7.49- 6.44
RWCD
109,052
109,052
109,052
SRP
140,121
108,575
51,487
217,627
109,052
109,052
109,052
SRP
171,009
108,575
51,487
217,627
109,052
109,052
109,052
SRP
175,959
113,525
56,437
222,577
165,489
RWCD
109,052
109,052
109,052
SRP
200,193
130,525
64,714
239,577
309,245
5.43- 4.80
160,539
RWCD
285,011
6.26- 5.44
160,539
RWCD
280,061
6.36- 6.27
114,234
166,164
249,173
6.43- 6.37
100,247
173,766
RWCD
112,349
112,349
112,349
SRP
214,365
137,029
64,714
326,714
249,378
177,063
123
Table 34.
(Continued).
1967
Price
Range
(Dollars!
Acre-Foot)
4.79- 2.00
District
District
Total
Selected Years
1990
District
Total
2020
District
Total
(Acre-Feet)
RWCD
118,037
118,037
118,037
SRP
249,215
165,895
83,744
367,248
283,932
201,781
Salt River Project quantities are in addition to three and
a.
one-half acre-feet per acre of project supplied assessment, normal flow
and stored and developed water (see Chapter II, Salt River Project).
Roosevelt Water Conservation District quantities are total
quantities that would be used at each price. Although approximately
34,000 acre-feet of water are received by the RWCD from the SRP (see
Chapter II, Roosevelt Water Conservation District) at a low variable cost,
it is not known how this will affect future water prices to the farmer.
It can be said, however, that the above estimated additional water quantities are on the high side since as the cost of pumping water increases,
less will be used, thereby, causing the 34,000 acre-feet received from
the SRP to become a larger percentage of the total water used.
124
next most inexpensive water, the quantity used will increase by 249,215
acre-feet under 1967 conditions, by 165,895 acre-feet in 1990, and by
83,744 acre-feet in 2020, in each case over the quantity of water that
would then be used from presently available sources in the absence of
additional and cheaper
supplies.
Net revenue produced in the SRP from the use of additional and
cheaper water at selected prices over the projection period is presented
in Table 35.
Under 1967 conditions in the SRP, a decrease in the cost of
marginally priced water from $7.50 to $2.00 per acre-foot would cause
net revenue in agriculture to increase by slightly less than one million
dollars ($16,537 million minus $15,592 million).
The increase in agri-
cultural net revenue resulting from lower prices marginal water would
decline over time, as would the use of marginal water, as shown in
Table 34, due to the decrease in available cropland in the SRP.
The
increases in net revenues and marginal water uses within years at
various lower marginal prices shown in the table reflects an increased
use of water to produce crops of low economic productivity and an increase
in net revenue due to a saving in water costs on crops that would be grown
using the higher priced water, as well as additional net returns obtained
from crops grown with the lower priced marginal water that would not be
grown at the higher water prices.
Assuming a continuing policy by the SRP to subsidize the cost of
project produced pump water (see Chapter IV, Water Supply Functions) to
its member water users at present levels, no additional or replacement
water would be used by them at costs over $7.50 per acre-foot.
The SRP,
125
Table 35.
Year
Projected Net Revenue at Selected Marginal Water Prices,
SRP and RWCD.
Irrigation
Selected Marginal Water Prices
District
8.50
7.50
4.80
2.00
(Net Revenue in Thousand Dollars)
1967
SRP
RWCD
2,446
15,592
15,907
16,537
2,550
2,885
3,164
1970
SRP
15,228
15,645
16,243
1975
SRP
14,628
15,025
15,537
1980
SRP
14,025
14,387
14,890
1985
SRP
13,454
13,788
14,241
1990
SRP
12,706
13,007
13,420
1995
SRP
11,706
11,987
12,359
2000
SRP
10,858
11,096
11,432
2005
SRP
10,059
10,267
10,564
2010
SRP
9,362
9,542
9,806
2015
SRP
8,608
8,767
9,000
2020
SRP
7,948
8,087
8,294
126
operating as a users' cooperative, might find it preferable for a variety
of reasons to subsidize additional and replacement water to users at
constant prices from some surface source rather than continuing to
subsidize the pumping costs of water obtained from the groundwater reservoir at ever increasing costs.
An analysis of water source alternatives
and their costs to the SRP as a cooperative would be necessary to ascertain the relative desirability to it of obtaining or developing alternative water sources at specific costs.
The analysis reported herein reveals only the quantities of water
agricultural users would find it profitable to acquire at a range of
marginal prices below, but not above the present SRP price of $7.50 per
acre-foot for project produced pump water.
This analysis has nothing to
say as to the quantities of water from other sources the SRP as a users'
cooperative might find desirable to buy and subsidize to its members in
replacement of the pumped water supplies it now produces.
In the RWCD, water is supplied to agriculture at a constant
average and marginal cost, as illustrated by the supply function in
Figure 8.
As shown, 104,164 acre-feet of water was demanded by agricul-
tural users under 1967 conditions at an average price of $8.50 per acrefoot.
Any increase or decrease in this average price will affect quantity
used to the degree indicated in Figure 3 and Table 33.
For selected water
prices between $15.13 (which is the projected cost to the district of
pumping water in 2020) and $2.00 per acre-foot, quantities of any available replacement supply that would be used in two selected future years
(1900 and 2020) are presented in Table 34.
Since land availability over
time is assumed to remain constant at the 1967 level in the RWCD, water
127
use over time will remain Constant at any constant water price, as
shown in Table 34.
Net revenue produced in the
RWCD
at selected water prices under
the conditions of 1967 is presented in Table 35.
A change in the price
of water from $8.50 to $2.00 per acre-foot would increase use by approximately 14,000 acre-feet, as shown in Table 34 (118,037) acre-feet minus
104,164 acre-feet).
The use of this additional water, together with the
saving in cost made possible on the 104,164 acre-feet formerly produced
by the district and sold to its members at $8.50 per acre-foot, would
cause agricultural net revenue to increase by $718,000, as shown in
Table 35 ($3.l64 million minus $2.446 million).
Since land availability
over time is constant, net revenue over time at any single price is also
variant.
The RWCD, operating as a users' cooperative, obtains approximately
two-thirds of its water supplies through its own pumps from underground
sources.
Over time, these supplies will become increasingly more expen-
sive, as shown in Table 17.
At any point in time, the project would be
willing to buy water from any other source at any delivery price equal
to or below its cost at that time of pumping groundwater, thereby,
steuauing, or at least slowing down, the rate of increase in the cost of
water to its members.
It is assumed in this analysis that the cost to
the district of pumping water in any given future year is the !lbreakevenU
price below which the district would purchase all its water from the
alternative source offering the lower price.
In summary, additional and replacement supplies of water in the
SRP would be of value to agricultural users only if the prices paid for
128
them were less than that now being paid for water from the most expensive
source (project pumped at $7.50 and private pumped at $6.44 per acrefoot).
The value of this water to farmers in future years at prices
below those paid in 1967 for the replaceable marginal quantities are those
presented in Table 35.
It is assumed that the SRP will not acquire water
at any price to replace the annual surface supply available to it because,
having no use for such a displaced supply, its marginal value to the
district is zero.
In the RWCD, the project and the water user are in the same
position relative to additional water supplies and their costs.
Their
position is identical to that of the SRP since increasing water costs
will be experienced by both the RWCD as a cooperative and the individual
water user.
CHAPTER VI
SUNMARY AND EVALUATION
A linear programming analysis of the present structure of agriculture in the SRP and RWCD of central Arizona shows a considerable
dependence upon Cotton, sugar beets and vegetables for the production
of net revenue.
These crops produce large amounts of net revenue per
acre and per acre-foot of water.
Acreage declines in cotton will occur
in response to declining land availability and to the need for a rotational balance rather than due to its economic inability to command
scarce resources other than cropland.
Sugar beet and vegetable acreages
remain nonvariant over the projection period.
At the present time,
alfalfa and small grain crops are netting relatively small returns per
acre and per acre-foot of water used.
As such, they are marginal users
of the scarce resources and declines in the acreages of these crops can
be expected as the land base decreases and/or the cost of irrigation
water increases over the projection period.
Projected adjustments in enterprise combination in the two
irrigation districts and in the study area have been presented.
The use
of land and water and the projected net revenue stemming from their use
over the 53_year projection period show for both the SRP and RWCD a
decrease in water use per cropped acre and an increasing net revenue per
acre-foot of water used (Table 36), though the latter increase is
considerably more marked in the SRP than in the RWCD.
129
Net revenue per
130
Table 36.
Year
Projected Net Revenue per Acre, WaterUse per Acre, and Net
Revenue per Acre-Foot of Water Used, SRP and RWCD.
Net Revenue
Water Use per
Net Revenue per
per Acre
Cropland Acre
Acre-Foot of Water
SRP
RWCD
SRP
RWCD
SRP
RWCD
- (Dollars)
-
- (Acre-Feet) -
(Dollars) -
1967
108.28
90.59
4.5
3.9
24.29
23.48
1970
111.16
88.30
4.5
3.9
24.94
22.89
1975
120.27
85.00
4.5
3.6
26.92
23.36
1980
129.86
83.81
4.4
3.6
29.42
23.03
1985
140.30
81.70
4.3
3.6
32.31
22.45
1990
149.23
79.96
4.2
2.3
35.18
34.33
1995
154.86
78.56
4.1
2.3
37.44
33.73
2000
161.80
77.11
4.0
2.3
39.96
33.11
2005
168.80
75.81
3.9
2.1
42.74
35.67
2010
176.95
74.59
3.8
2.1
46.11
35.10
2015
179.43
73.37
3.8
2.1
48.26
34.52
2020
190.57
71.85
3.8
2.1
50.75
33.81
131
acre of land cropped will also increase over time in the SRP, although
it will decrease in the RWCD, as shown in Table 36.
The decline in aggregate net revenue in the SRP over the projection period stems primarily from a decline in the availability of
agricultural land.
This decrease is a result of the encroachment of the
urban-industrial sector onto land currently being used by agriculture.
Declines in net returns to agriculture in the
RWCD
over the projection
period are the result solely of increasing irrigation water costs.
An analysis of water use by farmers over time at various hypoth-
esized water prices below those currently paid indicates relatively minor
effects upon net revenue and aggregate water quantity used, but a sizable
shift in the source of supply of water used.
The effects of lower water
costs to agricultural users in the SRP are of much less significance
than to the RWCD users because the present average cost of water in the
SRP is relatively low compared to its average cost in the RWCD, which
is approximately four times that in the SRP, and because of the growing
ability of the SRP to subsidize pumped water costs to its members through
net electrical power revenues.
This insulates them from the increasing
cost of pumping over time an increase which will affect
RWCD users.
The projections advanced herein in enterprise combinations, water
use and net revenue over the 53-year projection period are premised on a
continuation of many present conditions.
Primary among these assumptions
are an unchanging production technology, a constant cost-price structure
or one in which relative prices remain constant, a continuation of present
cropping patterns, continued growth in the urban-industrial sector at the
expense of the agricultural sector, an unchanging water quality, and a
132
maintenance of current institutions such as water supply organizations
and governmental administration of acreage and price controls on certain
crops.
A deviation in any of these assumed constants will affect the
rate or magnitude of the projections; however, the direction of change
could be affected only by relatively large changes in the factors
assumed to be nonvariant.
These would have to be of such magnitude as
a drastic reorganization of water supply organizations, changes in
cropping patterns equivalent to a discontinuation of cotton production,
or a markedly increased specialization in vegetable production.
Changes
of these magnitudes do not appear justifiably predictable at this time.
They do, however, suggest areas for future research into the degree to
which agriculture in the area is dependent on presently available technological and institutional conditions.
LIST OF REFERENCES
ARIZONA INTERSTATE STREAM COMMISSION
Arizona, Phoenix, Arizona.
ARIZONA WATER RESOURCES COMMITTEE
Water Resources, State of
1967
1957-1968
Proceedings 1-12, State of Arizona.
Arizona Watershed Symposium
BAIN, JOE S., RICHARD E. CAVES and JULIUS MARGOLIS
1966
Northern
California's Water Industry, Resources for the Future, Inc., The
Johns Hopkins Press, Baltimore.
1964 "Variable Resource Programming for Appraising Farm
Adjustment Opportunities," Agricultural Economics Research, Vol. XVI,
No. 1.
BOLTON, BILL
CITY OF PHOENIX AND MARICOPA COUNTY
l959a
Population Growth of the
l959b
Land Use of the Phoenix
Phoenix Urban Area, Phoenix, Arizona.
CITY OF PHOENIX AND MARICOPA COUNTY
Urban Area, Phoenix, Arizona.
COOPERATIVE EXTENSION SERVICE AND AGRICULTURAL EXPERIMENT STATION
1967
Arizona Agriculture, 1967, The University of Arizona, Bulletin A50,
Tucson, Arizona.
1968 Annual Report on Groundwater in Arizona Spring 1966 to
Spring 1967, Arizona State Land Department, Water Resources Report
No. 36, Phoenix.
COX, C. J.
DORFMAN, ROBERT, PAUL A. SAMUELSON and ROBERT M. SOLOW
1958
Prograiiuuing and Economic Analysis, McGraw-Hill, New York.
Linear
1954 A Suiiuiiary of Groundwater Legislation in Arizona,
Arizona State Land Department, Bulletin No. 301, Phoenix.
ERNST, ROBERT
n.d. "Couiuiercial Vegetable Production Guide for
Maricopa County," Agricultural Extension Service, College of Agriculture, The University of Arizona, Tucson.
FOERNAN, BOYCE R.
1968 "Legal and Administrative Controls on the Transfer
of Water in Arizona," Unpublished Master's Thesis, The University of
GOSS, JAMES W.
Arizona.
HEADY, EARL 0. and WILFRED CANDLER
1958
Linear Programming Methods,
Iowa State University Press, Ames, Iowa.
133
134
HEDGES, TRIMBLE R. and CHARLES V. MOORE
1962-1965 Economics of On-Farm
Irrigation Water Availability and Cost, and Related Farm Adjustments,
1-4, Giannini Foundation Research Reports No. 257, 261, 263 and 286,
California Agricultural Experiment Station.
n.d.
HOCK, KENNETH J.
"Agricultural Adjustments to a Falling Groundwater
Table in Central Arizona," Dissertation in Progress, The University
of Arizona, Tucson.
HURLEY VS. ABBOTT, et al. March 1, 1910 No. 4564 Decree. In Federal
District Court of 3rd Judicial District, Territory of Arizona in and
for the County of Maricopa.
JONES, DOUGLAS M.
1968 "Economic Aspects of Agricultural Use of Colorado
River Water in Yuma County, Arizona," Unpublished Dissertation, The
University of Arizona, Tucson.
"An Analysis of Pump Water Costs in Central
LANOREAUX, ROBERT D.
1966
Arizona," Unpublished Master's Thesis, The University of Arizona,
Tucson.
"Agricultural Value of Additional Surface Water
MACK, LAWRENCE E.
1965
in the Salt River Valley of Arizona," Unpublished Master's Thesis,
The University of Arizona, Tucson.
MACK, LAWRENCE E.
1968 Supplemental Report Entitled "Supplementary
Material in Support of Dissertation Entitled 'Economic Implications
of a Dynamic Land and Water Base for Agriculture in Central Arizona',"
File Report 68-2, Department of Agricultural Economics, The University
of Arizona, Tucson.
1963 The Politics of Water in Arizona, The University of
MANN, DEAN E.
Arizona Press, Tucson.
1962 "Economics of Water Dertand in Couuuercialized
MOORE, CHARLES V.
Agriculture," Journal American Water Works Association, Vol. 54, No. 8.
MOORE, CHARLES V. and TRIMBLE R. HEDGES 1963 "A Method for Estimating
the Demand for Irrigation Water," Agricultural Economics Research,
Vol. XV, No. 4.
Costs and Returns for Major Field Crops in
1965
NELSON, AARON G.
Central Arizona, Technical Bulletin 174, Agricultural Experiment
Station, The University of Arizona, Tucson.
NELSON, AARON G. and CHARLES D. BUSCH 1967 Cost of Pumping Irrigation
Water in Central Arizona, Technical Bulletin 182, Agricultural
Experiment Station, The University of Arizona, Tucson.
135
PAWSON, WALTER W. and AARON G. NELSON 1966 Economics of Skip-Row
Cotton Production, Report 231, Agricultural Experiment Station,
The University of Arizona, Tucson.
ROOSEVELT WATER CONSERVATION DISTRICT
Higley, Arizona.
l963-1968a
"Crop Report Summary,"
ROOSEVELT WATER CONSERVATION DISTRICT
Records," Higley, Arizona.
1963-l968b
"Water Production
SALT RIVER PROJECT
1962-1967
Annual Reports, Phoenix, Arizona.
SALT RIVER PROJECT
1962-1968
"Crop Reports," Phoenix, Arizona.
SALT RIVER PROJECT
1964
SALT RIVER PROJECT 1968a
Phoenix, Arizona.
Major Facts in Brief, Phoenix, Arizona.
"Irrigation Department Statistical Report,"
SALT RIVER PROJECT 1968b Planning and Project Development Division,
Unpublished Data, Phoenix, Arizona.
SALT RIVER VALLEY WATER USERS' ASSOCIATION
Irrigation Department.
1962
"Statistical Report,"
Its
"The Salt River Project of Arizona:
SMITH, COURTLAND L.
1968
Unpublished
Organization and Integration with the Community,"
Dissertation, The University of Arizona, Tucson.
1968 "Predicting Farmer Response to a Falling Water
STULTS, HAROLD M.
An Arizona Case Study," Unpublished Dissertation, The
Table:
University of Arizona, Tucson.
1965 Present and Future Water Use and Its Effects
THIELE, HEINRICH J.
on Planning in Maricopa County, Arizona, Maricopa County Department
of Planning and Zoning, Phoenix.
TIJORIWALA, ANILKIJMAR G., WILLIAM E. MARTIN and LEONARD C. BOWER 1968
The Structure of the Arizona Economy: Output Interrelationships and
Their Effects on Water and Labor Requirements, Part I, The InputOutput Model and Its Interpretation, Arizona Agricultural Experiment
Supplement,"
Station Technical Bulletin 180; and"Part II, Statistical
Agricultural Economics File Report 68-1, The University
Department of
of Arizona, Tucson.
United States Census of AgriculUNITED STATES BUREAU OF THE CENSUS 1961
United States Government Printing
1,
Part
43,
Arizona,
ture 1959, Vol.
Office, Washington, D. C.
136
UNITED STATES CONGRESS, SENATE May 2-5, 1967 Central Arizona Project,
Hearings Before the Subcommittee on Water and Power of the Committee
on Interior and Insular Affairs, United States Senate, Nineteenth
Congress, First Session on S.1004, S.1013, S.861, 5.1242 and S.1409.
Bills to Authorize the Construction, Operation and Maintenance of the
Central Arizona Project and Colorado River Project, and for Other
Purposes.
UNITED STATES DEPARTMENT OF AGRICULTURE 1967 The 1967 Upland Cotton
Program, Agriculture Stabilization and Conservation Service,
Publication No. PA-789.
1965 "Data Book on Power
UNITED STATES DEPARTMENT OF THE INTERIOR
Districts, Irrigation Districts and Cooperatives," Bureau of
Reclamation, Boulder City, Nevada.
1959 Economic Analysis and Projection
WESTERN BUSINESS CONSULTANTS, INC.
for Phoenix and Maricopa County, Phoenix, Arizona
1965 The Economy of Maricopa
WESTERN MANAGEMENT CONSULTANTS, INC.
County, 1965 to 1980, Phoenix, Arizona.
WHITE, NATALIE D., R. S. STULEK and CLARA L. RAUH 1964 Effects of
Groundwater Withdrawal in Part of Central Arizona Projected to
1969, Arizona State Land Department, Water Resources Report No. 16,
Phoenix, Arizona.
WYATT, RICK 1968 "SRP Land Use Projection," Planning and Project
Development Division, Salt River Project.
Data for
YOUNG, ROBERT A., WILLIAM E. MARTIN and DALE L. SHAW 1968
University of
College
of
Agriculture,
The
Arizona Crop Farm Planning,
Arizona, Tucson.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement