Analysis of Water Use Trends in the

United States: 1950-1995

FINAL PROJECT COMPLETION REPORT

Prepared for:

1999 USGS National Competitive Grants Program

Grant No. 99HQGR0222

Subgrant No. 00-312

United States Geological Survey

Reston, Virginia 20192

Prepared by:

Ben Dziegielewski, Professor, Department of Geography

Subhash C. Sharma, Professor, Department of Economics

Thomas J. Bik, Researcher, Department of Geography

Heru Margono, Graduate Assistant, Department of Economics

Xiaoying Yang, Graduate Assistant, Department of Geography

Southern Illinois University at Carbondale

Carbondale, IL 62901-4514

February 28, 2002

Page

Table of Contents............................................................................................................. ii

List of Tables................................................................................................................... x

List of Figures................................................................................................................ xx

Acknowledgement........................................................................................................ xxii

EXECUTIVE SUMMARY

Study Purpose............................................................................................... ES-1

Data and Methods......................................................................................... ES-1

National and State Trends.............................................................................. ES-2

Demand Drivers and Intensity of Use............................................................. ES-3

Determinants of Changes in Per Unit Use....................................................... ES-4

Structure of Water Use Models..................................................................... ES-6

Accuracy of State-level Predictions................................................................ ES-7

County-level Data and Models....................................................................... ES-8

Recommendations......................................................................................... ES-9

1. INTRODUCTION

Purpose of the Study........................................................................................ 1-1

Background of the NWUIP.............................................................................. 1-2

Setting the Framework: 1950 - 1960................................................................ 1-3

USGS Circular 115 ................................................................................... 1-3

USGS Circular 398 ................................................................................... 1-3

USGS Circular 456 ................................................................................... 1-4

Increasing Disaggregation and Explanation: 1965 - 1975................................... 1-4

USGS Circular 556 ................................................................................... 1-4

USGS Circular 676 ................................................................................... 1-6

USGS Circular 765 ................................................................................... 1-6

Federation Support and Implementation of the NWUIP: 1980 - 1995............... 1-7

USGS Circular 1001 ................................................................................. 1-7

USGS Circular 1004 ................................................................................. 1-9

USGS Circular 1081 ............................................................................... 1-10

USGS Circular 1200 ............................................................................... 1-10

Overview and Implications of the Water Use Inventory Data and Process....... 1-11

Chapter Synopsis........................................................................................... 1-12

References..................................................................................................... 1-14

2. STUDY APPROACH

Purpose........................................................................................................... 2-1

Modeling Framework ...................................................................................... 2-1

Data Structure............................................................................................ 2-1

Model Specification .................................................................................. 2-2

Dependent Variables........................................................................................ 2-3

Data Sources and Acquisition..................................................................... 2-3

Spatial Coverage........................................................................................ 2-3

Period of Analysis...................................................................................... 2-3

Sectoral Coverage..................................................................................... 2-4

Independent Variables...................................................................................... 2-5

Data Sources and Acquisition..................................................................... 2-5

Period of Analysis...................................................................................... 2-6

Categories of Independent Variables.......................................................... 2-6

Data Interpolation and Standardization Procedures..................................... 2-7

Data Validation Procedures.............................................................................. 2-8

Verification from USGS State Water Use Coordinators.............................. 2-9

Assessment of Overall Accuracy.......................................................... 2-9

Thermoelectric Accuracy Email Survey................................................. 2-9

Adjusting Weather Data to Correspond with Data Collection Years...... 2-9

Estimation and Diagnostic Procedures............................................................. 2-10

Modeling Approach................................................................................. 2-10

Modeling Diagnostic and Validation Procedures........................................ 2-11

Accuracy of Predictions................................................................................. 2-11

3. LONG-TERM NATIONAL TRENDS

Purpose........................................................................................................... 3-1

Trends in Total Withdrawals............................................................................. 3-1

Changes in Sectoral Withdrawals...................................................................... 3-3

Domestic Withdrawals............................................................................... 3-4

Industrial Withdrawals ............................................................................... 3-6

Irrigation Withdrawals ............................................................................... 3-8

Thermoelectric Withdrawals .................................................................... 3-10

Trends in Withdrawals by Source of Water..................................................... 3-13

Total Withdrawals.................................................................................... 3-13

Public Supply and Rural Domestic Withdrawals ....................................... 3-15

Industrial Withdrawals.............................................................................. 3-15

Irrigation Withdrawals.............................................................................. 3-16

Thermoelectric Withdrawals..................................................................... 3-17

Summary....................................................................................................... 3-18

References..................................................................................................... 3-19

4. STATE CONTRIBUTIONS TO NATIONAL TRENDS

Purpose........................................................................................................... 4-1

Trends in Total Withdrawals............................................................................. 4-1

Total Withdrawals and Associated Factors: 1995....................................... 4-2

Trends in Total Withdrawals and Associated Factors: 1960 - 1995............. 4-5

Trends in Total Withdrawals and Associated Factors: 1980 - 1995............. 4-7

Summary of Trends in Total State Withdrawals ........................................ 4-10

Trends in Public Supply and Rural Withdrawals.............................................. 4-10

Public-Supply and Rural Domestic Withdrawals and
Associated Factors: 1995................................................................... 4-10

Trends in Public Supply and Rural Domestic Withdrawals: 1960 - 1995.... 4-12

Trends in Public Supply and Rural Domestic Withdrawals: 1980 - 1995.... 4-13

Trends in State Population and Population Served by Public Supplies.. 4-14

Trends in Median Family Income........................................................ 4-16

Summary of Trends in Public Supply Withdrawals .................................... 4-16

Trends in Self-Supplied Industrial Withdrawals............................................... 4-16

Distribution of Self-Supplied Industrial Withdrawals: 1995........................ 4-17

Trends in Self-Supplied Industrial Withdrawals: 1960 - 1995.................... 4-19

Trends in Self-Supplied Industrial Withdrawals: 1980 - 1995.................... 4-19

Trends in Manufacturing and Mining Employment: 1960 - 1995................ 4-21

Summary of Trends in Self-Supplied Industrial Withdrawals...................... 4-24

Trends in Irrigation Withdrawals..................................................................... 4-25

Irrigation Withdrawals and Associated Factors: 1995................................ 4-25

Trends in Irrigation Withdrawals and Associated Factors: 1950 - 1995..... 4-28

Trends in Irrigation Withdrawals and Associated Factors: 1980 - 1995..... 4-29

Summary of Trends in Irrigation Withdrawals............................................ 4-33

Trends in Thermoelectric Withdrawals............................................................ 4-34

Distribution of Thermoelectric Withdrawals: 1995..................................... 4-34

Trends in Thermoelectric Withdrawals and Associated Factors:
1960 - 1980...................................................................................... 4-36

Trends in Thermoelectric Withdrawals and Associated Factors:
1980 - 1995...................................................................................... 4-38

Summary of Trends in Thermoelectric Withdrawals................................... 4-39

Chapter 4 Annex............................................................................................ 4-41

References..................................................................................................... 4-42

5. EXPLANATORY ANALYSIS OF HISTORICAL WITHDRAWALS

Purpose........................................................................................................... 5-1

Variability of Historical Withdrawals................................................................. 5-1

Total State Withdrawals .................................................................................. 5-2

Exploratory Regressions............................................................................. 5-3

Effects of Extensive (Driver) Variables........................................................ 5-5

Components of Change in Historical Withdrawals....................................... 5-8

Public Supply Withdrawals............................................................................. 5-11

Descriptive Statistics................................................................................ 5-11

Major Demand Drivers............................................................................ 5-11

Total State Population ....................................................................... 5-12

Population Served by Public Systems ................................................ 5-16

Components of Change in Historical Withdrawals .................................... 5-18

Multiple Regression Models of Total Public Supply Withdrawals .............. 5-20

Linear Model..................................................................................... 5-20

Log-Linear Model ............................................................................. 5-22

Multiple Regression Models of Per Capita Public Supply Withdrawals...... 5-24

Self-Supplied Industrial Withdrawal................................................................ 5-29

Descriptive Statistics................................................................................ 5-29

Major Demand Drivers............................................................................ 5-30

Total State Population........................................................................ 5-30

Industrial (Manufacturing and Mining) Employment............................. 5-32

Components of Change in Historical Withdrawals .................................... 5-33

Multiple Regression Models of Self-supplied Industrial Withdrawals ......... 5-34

Linear Model..................................................................................... 5-34

Log-Linear Model.............................................................................. 5-35

Multiple Regressions of Per Capita and Per Employee Withdrawals ......... 5-36

Per Capita Model of Industrial Withdrawals........................................ 5-37

Per Employee Model of Industrial Withdrawals................................... 5-37

Predictions of National Industrial Withdrawals and Changes ..................... 5-38

Irrigation Withdrawals ................................................................................... 5-40

Descriptive Statistics................................................................................ 5-40

Major Demand Drivers............................................................................ 5-41

Components of Change in Historical Withdrawals .................................... 5-42

Multiple Regression Models of Total Irrigation Withdrawals...................... 5-44

Multiple Regression Models of Per Unit Irrigation Withdrawals................. 5-46

Predictions of National Irrigation Withdrawals and Changes ..................... 5-47

Thermoelectric Withdrawals .......................................................................... 5-51

Descriptive Statistics................................................................................ 5-51

Major Demand Drivers............................................................................ 5-52

Components of Change in Historical Withdrawals .................................... 5-54

Multiple Regression Models of Total Thermoelectric Withdrawals ............ 5-55

Multiple Regression Models of Unit Thermoelectric Withdrawals .............. 5-57

Predictions of National Thermoelectric Withdrawals and Changes ............ 5-60

Chapter 5 Annex...................................................................................... 5-63

6. REGRESSION MODELS FOR PREDICTING AGGREGATE STATE WATER USE

Purpose........................................................................................................... 6-1

Desired Model Accuracy................................................................................. 6-2

Procedure for Developing “Predictive” Regression Models................................ 6-2

Regressions of Public-Supply Withdrawals....................................................... 6-4

Models of Total Public-Supply Withdrawals............................................... 6-5

Linear Regressions............................................................................... 6-5

Log-Linear Regressions ....................................................................... 6-9

Per Capita Withdrawal Models................................................................ 6-15

Linear Per Capita Models.................................................................. 6-15

Log-Linear Per Capita Models .......................................................... 6-19

Comparison of the Estimated Regression Models...................................... 6-23

Regressions of Industrial Water Use .............................................................. 6-23

Total Manufacturing Use Models.............................................................. 6-24

Linear Regressions............................................................................. 6-24

Log-Linear Regressions ..................................................................... 6-25

Per Employee Manufacturing Use Models................................................ 6-27

Linear Regressions of Per Employee Use............................................ 6-28

Log-Linear Regressions of Per Employee Use.................................... 6-29

Comparison of the Estimated Regression Models...................................... 6-34

Allocation of Manufacturing Use to Self-supplied and Public-supplied....... 6-34

Models of Irrigation Withdrawals ................................................................... 6-36

Models of Total Irrigation Withdrawals..................................................... 6-36

Models of Gross Irrigation Rate in Inches Per Year .................................. 6-39

Linear Models of Irrigation Depth....................................................... 6-39

Log-linear Models of Application Depth............................................. 6-41

Regional (East and West) Models of Irrigation Depth.......................... 6-43

Comparison of the Estimated Regression Models...................................... 6-44

Models of Thermoelectric Withdrawals........................................................... 6-45

Total Thermoelectric Withdrawal Models................................................. 6-46

Regressions of Per Unit Withdrawals ....................................................... 6-49

Linear Regressions of Per Unit Withdrawals........................................ 6-49

Log-Linear Regressions of Per Unit Withdrawals................................ 6-51

Comparison of the Estimated Regression Models...................................... 6-54

Models for Other Water-Use Categories........................................................ 6-55

Self-Supplied Domestic Use..................................................................... 6-55

Mining Withdrawals ................................................................................ 6-57

Total Mining Withdrawal Models........................................................ 6-57

Per Employee Mining Withdrawal Models.......................................... 6-60

Livestock Withdrawals ............................................................................ 6-63

References..................................................................................................... 6-65

Chapter 6 Annex............................................................................................ 6-66

7. BACKWARD AND FORWARD PREDICTIONS OF STATE WITHDRAWALS

Purpose........................................................................................................... 7-1

Definitions and Calculations of Forecast Error................................................... 7-1

Sources of Forecast Error.......................................................................... 7-2

The Forecast Error Variance...................................................................... 7-3

Error in a Univariate Regression Model................................................. 7-3

Error in a Multivariate Regression Model.............................................. 7-4

Forecast Error in Multiplicative Models................................................ 7-5

Variance of Total Withdrawals............................................................. 7-6

Trend-Reference Forecast.......................................................................... 7-6

Forecasts of Public-Supply Withdrawals........................................................... 7-7

Backcasts of Per Capita Withdrawals for 1980........................................... 7-7

Forecasts of Per Capita Withdrawals for 2000......................................... 7-10

Forecasts of Manufacturing Use..................................................................... 7-11

Backcasts of Per Employee Manufacturing Use for 1980.......................... 7-11

Forecasts of Per Employee Manufacturing Use for 2000........................... 7-14

Forecasts of Irrigation Withdrawals................................................................ 7-15

Backcasts of Irrigation Depth for 1980..................................................... 7-16

Forecasts of Irrigation Depth for 2000...................................................... 7-19

Forecasts of Withdrawals for Thermoelectric Power....................................... 7-20

Backcasts of Unit Thermoelectric Withdrawals for 1980........................... 7-21

Forecasts of Unit Thermoelectric Withdrawals for 2000............................ 7-23

Supplemental Forecasts.................................................................................. 7-24

Self-Supplied Domestic Use..................................................................... 7-24

Mining Withdrawals................................................................................. 7-27

Livestock Withdrawals............................................................................. 7-28

Forecasts of Total Withdrawals...................................................................... 7-30

Summary....................................................................................................... 7-31

References..................................................................................................... 7-31

Chapter 7 Annex............................................................................................ 7-32

8. ANALYSIS OF COUNTY-LEVEL WATER USE DATA

Purpose........................................................................................................... 8-1

Public-Supply Use........................................................................................... 8-1

Definition of Dependent Variable................................................................ 8-1

Total Public-Supply Deliveries.................................................................... 8-3

Distribution of Dependent Variable Values............................................ 8-3

Withdrawals and Deliveries versus Population Served........................... 8-4

Regressions of Total Public-Supply Deliveries ...................................... 8-6

Per Capita (Net) Public Supply Deliveries................................................... 8-8

Linear Models...................................................................................... 8-9

Log-Linear Models ........................................................................... 8-11

Summary................................................................................................. 8-14

Manufacturing Water Use............................................................................... 8-14

County-level Total Manufacturing Use...................................................... 8-14

Models of Per Employee Manufacturing Use............................................ 8-17

Summary................................................................................................. 8-21

Irrigation Withdrawals.................................................................................... 8-21

County-level Total Irrigation Withdrawals................................................. 8-21

Models of Irrigation Depth....................................................................... 8-27

Models for Counties in Eastern States ................................................ 8-28

Models for Counties in Western States .............................................. 8-30

Summary................................................................................................. 8-33

Chapter 8 Annex............................................................................................ 8-34

9. ANALYSIS OF COUNTY-LEVEL WATER USE BY STATE

Purpose........................................................................................................... 9-1

Estimation Method........................................................................................... 9-1

Public-Supply Use........................................................................................... 9-2

Comparison of National and State-specific Results...................................... 9-2

Descriptive Statistics............................................................................ 9-2

Linear Regressions of Per Capita Deliveries.......................................... 9-4

Log-Linear Regressions of Per Capita Deliveries................................... 9-6

Accuracy of In-sample Predictions ...................................................... 9-7

Manufacturing Use........................................................................................... 9-9

Comparison of National and State-specific Results...................................... 9-9

Descriptive Statistics............................................................................ 9-9

Linear Regressions of Per Employee Uses.......................................... 9-11

Log-Linear Regressions of Per Employee Uses................................... 9-12

Accuracy of In-sample Predictions .................................................... 9-14

Irrigation Withdrawals.................................................................................... 9-16

Comparison of National and State-specific Results.................................... 9-16

Descriptive Statistics.......................................................................... 9-16

Linear Regressions of Gross Irrigation Depth...................................... 9-16

Log-Linear Regressions of Gross Irrigation Depth............................... 9-21

Accuracy of In-sample Predictions .................................................... 9-23

Summary....................................................................................................... 9-25

Chapter 9 Annex............................................................................................ 9-26

County Level Models for Arkansas.......................................................... 9-26

Public Supply Use.............................................................................. 9-26

Manufacturing Use............................................................................. 9-28

Irrigation Withdrawals........................................................................ 9-30

County Level Models for Kansas............................................................. 9-32

Public Supply Use.............................................................................. 9-32

Manufacturing Use............................................................................. 9-34

Irrigation Withdrawals........................................................................ 9-36

County Level Models for Oregon............................................................. 9-38

Public Supply Use.............................................................................. 9-38

Manufacturing Use............................................................................. 9-40

Irrigation Withdrawals........................................................................ 9-41

County Level Models for North Carolina.................................................. 9-42

Public Supply Use.............................................................................. 9-42

Manufacturing Use............................................................................. 9-44

Irrigation Withdrawals........................................................................ 9-46

10. CONCLUSIONS AND RECOMMENDATIONS

Synopsis........................................................................................................ 10-1

Principal Findings........................................................................................... 10-1

Recommendations for Further Research.......................................................... 10-4

Summary....................................................................................................... 10-5

APPENDIX A

State Level Variables....................................................................................... A-2

Description of Public Supply Variables....................................................... A-2

Description of Industrial Variables.............................................................. A-6

Description of Irrigation Variables............................................................ A-11

Description of Thermoelectric Variables................................................... A-14

County Level Variable Definitions and Data Tables........................................ A-19

Description of Public Supply Variables..................................................... A-19

Description of Industrial Variables............................................................ A-22

Description of Irrigation Variables............................................................ A-25

APPENDIX B. CONSULTATIONS WITH USGS STAFF

Purpose........................................................................................................... B-1

General Accuracy Assessment......................................................................... B-2

Introduction............................................................................................... B-2

Response.................................................................................................. B-2

Accuracy of Specific Thermoelectric Withdrawal Data..................................... B-6

Introduction............................................................................................... B-6

Response.................................................................................................. B-6

Alignment of Weather Data to Water Withdrawal Data Collection Time Frames B-8

Introduction............................................................................................... B-8

Response.................................................................................................. B-8

LIST OF TABLES

ES.1 Components of the 1950-1995 Changes in Sectoral Withdrawals................... ES-3

ES.2 Effects of Historical Changes in Explanatory Variables on Per Unit Water
Withdrawals at State Level: from Log-Linear Regression Models............ ES-5

ES.3 Elasticities of Key Explanatory Variables in Log-Linear Regression Models.... ES-6

ES.4 Accuracy of In-sample (1985-1995) and Out-of-sample (1980)
Predictions of State Total Withdrawals .................................................. ES-7

ES.5 Comparison of 1995 Estimates and 2000 Predictions..................................... ES-8

ES.6 In-sample Prediction Errors of Log-Linear County-Level Models .................. ES-8

2.1 General Categories of Explanatory Variables.................................................... 2-7

3.1 Total Water Withdrawals and Demographic and Economic Variables................ 3-2

3.2 Changes in Sectoral Withdrawals ..................................................................... 3-4

3.3 Population and Domestic Withdrawals ............................................................. 3-4

3.4 Domestic Withdrawals and Medial Family Income ........................................... 3-5

3.5 Self -Supplied Industrial Withdrawals and Manufacturing Employment .............. 3-7

3.6 Total Irrigation Withdrawals and Irrigated Acres .............................................. 3-9

3.7 Self-Supplied Thermoelectric Withdrawals and Production ............................. 3-11

3.8 Thermoelectric Generation from Different Sources ......................................... 3-13

3.9 Total and Percent of Withdrawals by Source: 1950-1995 .............................. 3-14

3.10 Groundwater and Surface Water Withdrawals in Public Supply and
Rural Domestic Sectors ......................................................................... 3-15

3.11 Self-Supplied Industrial Withdrawals by Source ............................................. 3-16

3.12 Irrigation Withdrawals by Source ................................................................... 3-17

3.13 Thermoelectric Withdrawals by Source........................................................... 3-17

3.14 Summary of Component Trends and Likely Causes ....................................... 3-18

4.1 Ranking of 1995 State Water Withdrawals by Water-Use Sector,
Top Ten States......................................................................................... 4-2

4.2 Percent Shares of Withdrawal and Associated Demographic and Economic

Measures the Ten States with the Largest Withdrawals ............................ 4-4

4.3 Changes in Manufacturing and Mining Employment and Industrial Withdrawals
(Selected States): 1980-1995................................................................. 4-21

4.4 Employment in Total Manufacturing and Water-Intensive SIC Categories,
1950-1995 ............................................................................................ 4-22

4.5 Employment in Water-Intensive SIC Categories
(Selected States): 1980-1995................................................................. 4-23

4.6 States Reporting More than 20,000 Mining Employees in 1995:
Employees, Withdrawals and Per Employee Withdrawals ....................... 4-24

4.7 Distribution of Irrigation Withdrawals, Acres, Annual Application and
Estimated Pumping Costs (Selected States): 1995 .................................. 4-27

4.8 Changes in Irrigation Withdrawals in Selected States:
1960-1995 and 1980-1995.................................................................... 4-30

4.9 Changes in Irrigated Acreage, Withdrawals, and Application Rate:
1980-1995............................................................................................. 4-32

4.10 Energy Pumping Costs (1995$/ac) for Selected States, 1980–1995,
Ranked by 1995 Costs........................................................................... 4-33

4.11 Thermoelectric Withdrawals, Population, and Gross State Product
in the 20 States with the Largest Thermoelectric Withdrawals, 1995 ....... 4-34

4.12 Changes in Thermoelectric Withdrawals versus Changes in Potential
Explanatory Factors in the States with the Largest Changes in Withdrawals,
1960 to 1980........................................................................................ 4-38

4.13 Changes in Thermoelectric Withdrawals versus Changes in Potential
Explanatory Factors in the States with the Largest Changes in Withdrawals,
1980 to 1995......................................................................................... 4-39

4A.1 Values of Total State Withdrawals and Associated Factors, 1995................... 4-41

5.1 Descriptive Statistics of USGS Estimates of Total and Sectoral Withdrawals:
1950-1995............................................................................................... 5-2

5.2 Descriptive Statistics of Total Withdrawals (mgd) by Year: 1950-1995............. 5-2

5.3 Regression of Total State Withdrawals: 1950-1995.......................................... 5-4

5.4 Regression of Total Water Withdrawals on Demand Drivers: 1950-1995.......... 5-5

5.5 Regression of Total Withdrawal on Demand Drivers: Parameter Estimates
for Each Data Year .................................................................................. 5-7

5.6 Linear Regression of Total Withdrawals: 1950-1975 and 1980-1995 ............... 5-8

5.7 Components of Historical Change in Total Withdrawals (mgd): 1960-1980....... 5-9

5.8 Components of Historical Change in Total Withdrawals (mgd): 1980-1995....... 5-9

5.9 Comparison of Sectoral Withdrawal Changes Estimated by USGS Inventories
and Linear Regression Models (bgd): 1960-1980 and 1980-1995......... 5-10

5.10 Descriptive Statistics for Public Supply Withdrawals (mgd): 1950-1995.......... 5-11

5.11(a) Linear and Log-linear Regressions of Public Supply Withdrawals on
Total State Population: 1950-1995........................................................ 5-14

5.11(b) Bivariate Relationships between Total Public Supply Withdrawals and
Total State Population: 1950-1995........................................................ 5-15

5.12 Conditional Mean and Median Per Capita Rates of Public Supply
Withdrawals Derived from Bivariate Regression Models: 1950-1995..... 5-16

5.13 Linear and Log-Linear Regressions of Public Supply Withdrawals on
Population Served: 1950-1995.............................................................. 5-17

5.14 Bivariate Relationships between Total Public Supply Withdrawals and
Total Population Served: 1950-1995..................................................... 5-18

5.15 Conditional Per Capita Rates of Public Supply Withdrawals Derived from
Bivariate Regression Models with Population Served: 1950-1995.......... 5-18

5.16 Historical Change in Withdrawals and Per Capita Rates.................................. 5-19

5.17 Components of the 1950-1995 Change in Withdrawals.................................. 5-19

5.18 Stepwise Linear Regression of Total Public Supply Withdrawals: 1950-1995 . 5-21

5.19 Stepwise Log-Linear Regression of Public Supply Withdrawals: 1950-1995... 5-23

5.20 Comparison of Estimated Coefficients of Log-Linear Regression for
Two Time Periods: 1950-1975 vs 1980-1995....................................... 5-24

5.21 Linear Regression of Per Capita Public Supply Withdrawals:

1950-1995........................................................................................... 5-25

5.22 Log-Linear Regression of Per Capita Public Supply Withdrawals:
1950-1995........................................................................................... 5-26

5.23 Predicted vs Actual Values of Per Capita Withdrawals with
Log-Linear Regression.......................................................................... 5-27

5.24 Log-Linear Regression of Per Capita Public Supply Withdrawals Using
Only Continuous Variables: 1950-1995................................................. 5-28

5.25 Predicted Values vs Actual Values of Per Capita Withdrawals with
Log-Linear Regression: 1950-1995....................................................... 5-28

5.26 Descriptive Statistics of Self-Supplied Industrial Withdrawals (mgd):
1950-1995........................................................................................... 5-29

5.27 Correlation between Self-Supplied Industrial Withdrawals and
Potential Driver Variables: 1960-1995................................................... 5-30

5.28 Linear and Log-Linear Regression of Industrial Withdrawals on State
Population: 1960-1995......................................................................... 5-31

5.29 Descriptive Statistics of Per Capita Industrial Withdrawals for Individual
Data Years (gpcd)................................................................................ 5-31

5.30 Linear and Log-Linear Regression of Industrial Withdrawals on
Industrial Employment: 1960-1995........................................................ 5-32

5.31 Descriptive Statistics of Per Employee Withdrawals for Each
Data Year (gped) ................................................................................. 5-32

5.32 Historical Changes in Industrial Withdrawals, Population and Per Capita Use . 5-33

5.33 Component Effects of Historical Changes in Population and Withdrawals........ 5-33

5.34 Historical Changes in Withdrawals, Employment and Per Employee Use......... 5-34

5.35 Component Effects of Historical Changes in Employment and Withdrawals...... 5-34

5.36 Linear Regression of Total Self-Supplied Industrial Withdrawals
(stepwise variable selection): 1960-1995 .............................................. 5-35

5.37 Log-Linear Regression of Total Self-Supplied Industrial Withdrawals
(stepwise variable selection): 1960-1995 .............................................. 5-36

5.38 Log-Linear Regression of Per Capita Industrial Withdrawals........................... 5-37

5.39 Log-Linear Regression of Per Employee Industrial Withdrawals: 1960-1995 .. 5-38

5.40 Components of Change in Industrial Withdrawals Per Employee
(gallons per employee per day): 1960-1995........................................... 5-39

5.41 Comparison of Reported and Predicted Self-Supplied Industrial Withdrawals
Re-estimated Using only Continuous Variables: 1960-1995................... 5-39

5.42 Descriptive Statistics of Total Irrigation Withdrawals (mgd): 1950-1995.......... 5-40

5.43 Comparison of Irrigation Withdrawals, 1950-1995......................................... 5-41

5.44 Linear and Log-Linear Regressions of Irrigation Withdrawals on
Irrigated Acres: 1950-1995................................................................... 5-41

5.45 Trend in Relationship between Irrigated Acres and Withdrawals: 1950-1995... 5-42

5.46 Historical Changes in Withdrawals (AF/yr), Irrigated Acres and Per
Acre Application................................................................................... 5-43

5.47 Components of the 1950-1980 Change in Withdrawals.................................. 5-43

5.48 Components of the 1980-1995 Change in Withdrawals.................................. 5-44

5.49 Linear Stepwise Regression of Total Irrigation Withdrawals............................. 5-45

5.50 Log-Linear Stepwise Regression of Total Irrigation Withdrawals..................... 5-46

5.51 Linear Regression of Irrigation Depth in Inches Per Year, All States:
1950-1995........................................................................................... 5-46

5.52 Linear Regression Models of Average Irrigation Depth for Eastern and
Western States, 1950-1995.................................................................. 5-47

5.53 Log-Linear Models of Average Irrigation Depth for Eastern and
Western States ..................................................................................... 5-48

5.54 Comparison of Predicted and Reported Average Depth of Irrigation
(inches per year): 1950-1995 ............................................................... 5-49

5.55 Components of Change in Irrigation Depth: Western States: 1965-1995;
Eastern States: 1950-1995.................................................................... 5-50

5.56 Descriptive Statistics of Thermoelectric Withdrawals (mgd):1960-1995........... 5-51

5.57 Linear and Log-Linear Regressions of Thermoelectric Withdrawals on
Thermoelectric Generation (46 states): 1960-1995................................ 5-53

5.58 Bivariate Relationships between Total Thermoelectric Withdrawals (mgd/yr)
and Total State Thermoelectric Generation (mkWh/yr): 1960-1995........ 5-53

5.59 Unit Thermoelectric Withdrawals Derived from Bivariate Regression Models:
1950-1995........................................................................................... 5-54

5.60 Components of the 1960-1995 Changes in Thermoelectric Withdrawals......... 5-54

5.61 Linear Regression of Thermoelectric Withdrawals (stepwise variable selection):
1960–1995........................................................................................... 5-56

5.62 Log-Linear Regression of Thermoelectric Withdrawals (stepwise variable Selection):
1960-1995........................................................................................... 5-57

5.63 Linear Regression Model of Per Unit Thermoelectric Generation Withdrawals:
1960-1995........................................................................................... 5-59

5.64 Log-Linear Regression Model of Per Unit Thermoelectric Generation Withdrawals:
1960-1995........................................................................................... 5-60

5.65 Predicted Values versus Actual Values of Unit Thermoelectric Withdrawals,
Log-Linear Regression: 1960-1995....................................................... 5-61

5.66 Predicted Changes versus Actual Changes of Unit Thermoelectric Withdrawals,
Log-Linear Model: 1960-1995............................................................. 5-62

5A.1 Linear Regression Model of Total Water Withdrawals: 1950-1995................. 5-63

5A.2 Regression with Transformed Values of Total Water Withdrawals: 1950-1995
(best Box-Cox transformation).............................................................. 5-64

5A.3 Historical State-level Per Capita Public Supply Withdrawals Derived from
USGS Estimates of Population Served................................................... 5-65

5A.4 Preliminary Linear Regression Model of Public Supply Withdrawals:
1950-1995........................................................................................... 5-66

5A.5 Preliminary Log-Linear Regression Model of Public Supply Withdrawals:
1950-1995........................................................................................... 5-67

5A.6 Linear Regression of Self-Supplied Industrial Withdrawals (full set of variables):
1960-1995 .......................................................................................... 5-68

5A.7 Log-Linear Regression of Self-Supplied Industrial Withdrawals (full set of variables):
1960-1995........................................................................................... 5-69

5A.8 Descriptive Statistics of Total Irrigation Withdrawals (acre-feet): 1950-1995... 5-70

5A.9 Linear Regression of Irrigation Withdrawals (full set of variables): 1950-1995.. 5-70

5A.10 Log-Linear Regression of Irrigation Withdrawals (full set of variables):
1950-1995........................................................................................... 5-71

5A.11 Linear Regression Model of Thermoelectric Withdrawals (full set of variables):
1960-1995........................................................................................... 5-72

5A.12 Log-Linear Regression of Thermoelectric Withdrawals (full set of variables):
1960-1995........................................................................................... 5-73

6.1 Model Notation System Using Public Supply as an Example............................. 6-4

6.2 Model IA: Linear Regression Model (mgd) of Total Public Supply Withdrawals:
1985-1995 ............................................................................................ 6-5

6.3 Effects of Outliers on Regression Coefficients in Model IA................................ 6-7

6.4 Predictive Linear Models for Public-Supply Total Withdrawals....................... 6-10

6.5 Model IB: Log-Linear Regression of Total Public-Supply Withdrawals (mgd).. 6-11

6.6 Effects of Outliers on Regression Coefficients in Log-Linear Model of
Total Public Supply Withdrawals (from Table 6.5) ................................ 6-12

6.7 Predictive Log-Linear Model of Total Public Supply Withdrawals................... 6-14

6.8 Model IC: Linear Regression of Per Capita Public Supply Withdrawals (gpcd) 6-15

6.9 Effects of Outliers on Regression Coefficients in Linear Model of Per Capita
Public Supply Withdrawals.................................................................... 6-16

6.10 Predictive Linear Model of Per Capita Public Supply Withdrawals.................. 6-17

6.11 Model ID: Log-Linear Regression of Per Capita Public Supply Withdrawals... 6-19

6.12 Effects of Outlier on Regression Coefficients in Log-Linear Model of Per
Capita Public Supply Withdrawals......................................................... 6-20

6.13 Predictive Log-Linear Model of Per Capita Public-Supply Withdrawals.......... 6-21

6.14 Model ID_4: Log-Linear Regressions of Per Capita Public
Supply Withdrawals.............................................................................. 6-22

6.15 Comparison of Estimated Models of Public Supply Withdrawals..................... 6-23

6.16 Model IIA: Linear Regression of Total Manufacturing Withdrawals................. 6-24

6.17 Model IIA_2: Linear Regression of Total Manufacturing Withdrawals............. 6-25

6.18 Model IIB: Log-Linear Regression of Total Manufacturing Use....................... 6-26

6.19 Predictive Log-Linear Models for Total Manufacturing Use............................. 6-27

6.20 Model IIC: Linear Regression of Per Employee Manufacturing Use................ 6-28

6.21 Predictive Linear Models of Per Employee Manufacturing Use........................ 6-29

6.22 Model IID: Log-Linear Regression of Per Employee Manufacturing Use......... 6-30

6.23 Effects of Outliers on Regression Coefficients in the Log-Linear Regression
of Per Employee Manufacturing Use ..................................................... 6-30

6.24 Predictive Log-Linear Model for Per Employee Manufacturing Use................. 6-32

6.25 Model IID_4: Final Predictive Log-Linear Model of Per Employee
Manufacturing Use................................................................................ 6-33

6.26 Comparison of the Estimated Models of Manufacturing Withdrawals............... 6-34

6.27 Linear Regression of Percent of Self-Supplied Manufacturing Use................... 6-35

6.28 Model IIIA: Linear Regression of Total Irrigation Withdrawals (mgd).............. 6-36

6.29 Model IIIB: Log-Linear Regression of Total Irrigation Withdrawals (mgd)...... 6-37

6.30 Predictive Log-Linear Models of Total Irrigation Withdrawals (mgd)............... 6-38

6.31 Model IIIC: Linear Regression of Gross Irrigation Depth (in/yr)....................... 6-39

6.32 Predictive Linear Model of Average Irrigation Depth (in/yr)............................. 6-40

6.33 Model IIID: Log-Linear Model for Irrigation Depth (in/yr).............................. 6-41

6.34 Predictive Log-Linear Regression Models of Irrigation Depth.......................... 6-42

6.35 Model IIIE: Log-Linear Regression of Irrigation Depth for
Fourteen Western States (in/yr) ............................................................ 6-43

6.36 Model IIIF: Log-Linear Regression of Irrigation Depth for
Thirty-four Eastern States (in/yr) ........................................................... 6-44

6.37 Comparison of Models of Irrigation Withdrawals............................................ 6-45

6.38 Model IVA: Linear Regression of Total Thermoelectric Withdrawals (mgd)..... 6-46

6.39 Model IVB: Log-Linear Model of Total Thermoelectric Withdrawals (mgd).... 6-47

6.40 Predictive Log-Linear Model of Total Thermoelectric Withdrawals (mgd)....... 6-48

6.41 Model IVC: Linear Regression of Per Unit Thermoelectric Withdrawals.......... 6-49

6.42 Predictive Linear Model of Per Unit Thermoelectric Withdrawals.................... 6-50

6.43 Model IVD: Log-Linear Model of Per Unit Thermoelectric Withdrawals
(gal./kWh)............................................................................................ 6-51

6.44 Predictive Log-Linear Model of Unit Thermoelectric Withdrawals (gal./kWh).. 6-52

6.45 Model IVD_4: Final Predictive Log-Linear Model of Unit Thermoelectric
Withdrawals (gal./kWh)........................................................................ 6-53

6.46 Comparison of the Estimated Models of Thermoelectric Withdrawals.............. 6-54

6.47 Linear Regression Model of Per Capita Self-Supplied Domestic
Water Withdrawals............................................................................... 6-56

6.48 Model VA: Linear Model of Total Mining Withdrawals................................... 6-57

6.49 Model VB: Log-Linear Models for Total Mining Withdrawals (mgd)............... 6-58

6.50 Predictive Log-Linear Models of Total Mining Withdrawals............................ 6-59

6.51 Model VD: Log-Linear Model of Unit Mining Withdrawals
(gallons/mining employee/day)............................................................... 6-60

6.52 Predictive Log-Linear Model of Unit Mining Withdrawals
(gallons/mining employee/day)............................................................... 6-61

6.53 Model VD_4: Final Predictive Log-Linear Model of Unit Mining Withdrawals
(gallons/mining employee/day)............................................................... 6-62

6.54 Model VID_4: Linear Regression Model of Livestock Withdrawals................ 6-64

6A.1 Regression Model of Percent Population Served by Public Water Supply Systems
(1980-1995)......................................................................................... 6-66

6A.2 In-Sample Predictions of Total Public Supply Withdrawals
(mgd, Model IB_2 & Model IB_3)...................................................... 6-67

6A.3 In-Sample Predictions of Per Capita Public Supply Withdrawals
(gpcd, Model ID).................................................................................. 6-68

6A.4 In-Sample Predictions of Percent of Population Served: 1985-1995................ 6-69

6A.5 In-Sample Predictions of Per Employee Manufacturing Withdrawals
(gped, Model IID_4)............................................................................ 6-70

6A.6 In-Sample Predictions of Percent of Self-Supplied: 1985-1995
(from Table 6.27) ................................................................................. 6-71

6A.7 Comparison of Predicted and Actual Values of Irrigation Depth
in Western States (in/yr, Model IIIE)..................................................... 6-72

6A.8 Comparison of Predicted and Actual Values of Irrigation Depth
in Eastern States (in/yr, Model IIIF)....................................................... 6-73

6A.9 Comparison of Predicted and Actual Values of Unit Thermoelectric
Withdrawals (gal./kWh, Model IVD_4)................................................. 6-74

6A.10 Calculated Per Capita Rates for Self-Supplied Domestic
Withdrawals (gpcd) .............................................................................. 6-75

7.1 Backcast of Per Capita Public Supply Withdrawals: 1980................................. 7-9

7.2 Forecast of State-level Per Capita Public Supply Withdrawals: 2000............... 7-10

7.3 Backcast of Per Employee Water Use in Manufacturing: 1980........................ 7-13

7.4 Forecast of Per Employee Water Use in Manufacturing: 2000......................... 7-14

7.5 Backcast of Irrigation Depth in Western States: 1980...................................... 7-16

7.6 Backcast of Irrigation Depth in Eastern and Central States: 1980..................... 7-18

7.7 Forecast of Irrigation Depth in Western States: 2000...................................... 7-19

7.8 Forecast of Irrigation Depth in Eastern and Central States: 2000..................... 7-20

7.9 Backcast of Withdrawals Per Kilowatt-hour: 1980......................................... 7-22

7.10 Forecast of Per Kilowatt-hour Use: 2000....................................................... 7-24

7.11 Backcast of Per Capita Self-Supplied Rural Domestic
Withdrawals: 1980................................................................................ 7-25

7.12 Forecast of Per Capita Self-Supplied Rural Domestic Withdrawals for
Specific States: 2000............................................................................. 7-26

7.13 Forecast of Per Employee Mining Withdrawals: 2000..................................... 7-27

7.14 Backcast of Total Livestock Withdrawals: 1980............................................. 7-28

7.15 Forecast of Total Livestock Withdrawals for Specific States: 2000.................. 7-29

7.16 Forecast of Sectoral and Total Withdrawals: 2000 (mgd)................................ 7-30

7A.1 Predicted Total Public Supply Withdrawals: 1980-2000................................. 7-32

7A.2 Predicted Self-Supplied Manufacturing Withdrawals: 1980-2000.................... 7-37

7A.3 Predicted Irrigation Withdrawals (Eastern and Central States): 1980-2000...... 7-42

7A.4 Predicted Irrigation Withdrawals (Western States): 1980-2000....................... 7-45

7A.5 Predicted Thermoelectric Withdrawals: 1980-2000........................................ 7-47

8.1 Comparison of Withdrawals and Deliveries in Two Subsets of
U.S. Counties (mgd): 1995...................................................................... 8-3

8.2 Descriptive Statistics of Public Net Supply Deliveries (mgd).............................. 8-3

8.3 Bivariate Regressions of Total Public Supply Withdrawals and Deliveries
on Population Served.............................................................................. 8-4

8.4 Linear Model of Total (Net) Public Supply Withdrawals................................... 8-6

8.5 Log-Linear Model of Total (Net) Public Supply Deliveries
(9,166 observations) .............................................................................. 8-7

8.6 Log-Linear Model of Total (Net) Public Supply Deliveries
(8,842 observations) .............................................................................. 8-8

8.7 Descriptive Statistics for Per Capita Public Supply Deliveries (gpcd)................. 8-9

8.8 Linear Model of Per Capita Public Supply Deliveries (all observations).............. 8-9

8.9 Linear Predictive Model of Per Capita Public Supply Deliveries...................... 8-10

8.10 Log-Linear Model of Per Capita Public Supply Deliveries
(all observations)................................................................................... 8-12

8.11 Log-Linear Predictive Model of Per Capita Public-Supply Deliveries.............. 8-13

8.12 Descriptive Statistics for County-level Total Manufacturing
Withdrawals and Deliveries (mgd)......................................................... 8-14

8.13 Bivariate Regression of Total Manufacturing Use on Employment.................... 8-15

8.14 Linear and Log-Linear Models of Total Manufacturing Use (mgd)................... 8-16

8.15 Descriptive Statistics of Per Employee Manufacturing Use............................... 8-17

8.16 Linear and Log-Linear Models of Per Employee Manufacturing
Water Use (gped)................................................................................. 8-18

8.17 Linear and Log-Linear Models of Per Employee Manufacturing Water
Use (removed observations where gped > 97.5 percentile).................... 8-19

8.17(a) Regressions of Per Employee Manufacturing Use with Outlier
Variables.............................................................................................. 8-20

8.18 Descriptive Statistics of County-level Total Irrigation Withdrawals
(mgd): 1985-1995................................................................................ 8-21

8.19 Bivariate Models of Total Irrigation Withdrawals on Irrigated
Area (mgd)........................................................................................... 8-22

8.20 Linear Regression of Total Irrigation Withdrawals: All Counties....................... 8-26

8.21 Log-Linear Regression of Total Irrigation Withdrawals: All Counties................ 8-26

8.22 Linear Regressions of Annual Depth of Irrigation: All Counties......................... 8-27

8.23 Linear and Log-Linear Models of Annual Irrigation Depth
for Counties in Eastern States................................................................ 8-28

8.24 Linear and Log-linear Models of Irrigation Depth with Outliers:
for Counties in Eastern States................................................................ 8-29

8.25 Linear Regression of Irrigation Depth: Counties in Western States................... 8-30

8.26 Log-Linear Regression of Irrigation Depth: Counties in Western States............ 8-31

8.27 Predictive Regression Models of Irrigation Depth: Counties in
Western States ..................................................................................... 8-32

8A.1 Identification of Outlier Counties and Years, by Withdrawal Sector................. 8-34

9.1 Descriptive Statistics for Public Supply Deliveries.............................................. 9-3

9.2 Linear Regressions of Per Capita Public Supply Deliveries Using
All Observations..................................................................................... 9-4

9.3 Linear Regressions of Per Capita Public Supply Deliveries with
Corrections for Outliers........................................................................... 9-5

9.4 Log-Linear Regressions of Per Capita Public Supply Deliveries for All Observations 9-6

9.5 Log-Linear Regressions of Per Capita Public Supply Deliveries with
Corrections for Outliers........................................................................... 9-7

9.6 Comparison of Predictive Properties of Linear Models of Per Capita
Public Supply Deliveries.......................................................................... 9-8

9.7 Comparison of Predictive Properties of Log-Linear Models of Per
Capita Public Supply Deliveries .............................................................. 9-9

9.8 Descriptive Statistics for Manufacturing Withdrawals....................................... 9-10

9.9 Linear Regressions of Per Employee Use Using All Observations.................... 9-11

9.10 Linear Regressions of Per Employee Use with Corrections for Outliers............ 9-12

9.11 Log-Linear Regressions of Per Employee Use Using All Observations............. 9-13

9.12 Log-Linear Regressions of Per Employee Use with Corrections
for Outliers............................................................................................ 9-13

9.13 Comparison of Predictive Properties of Linear Models of Per Employee Manufacturing Use 9-14

9.14 Comparison of Predictive Properties of Log-Linear Models of Per
Employee Manufacturing Use................................................................ 9-15

9.15 Descriptive Statistics for Irrigation Withdrawals and Gross Application
Depth................................................................................................... 9-17

9.16(a) Linear Regressions of Irrigation Depth Using All Observations in
Eastern and Central States..................................................................... 9-18

9.16(b) Comparison of Linear Regressions of Irrigation Depth Using All
Observations in Western States............................................................. 9-19

9.17(a) Comparison of Linear Regressions of Irrigation Depth with Corrections
for Outliers in Eastern and Central States............................................... 9-20

9.17(b) Comparison of Linear Regressions of Irrigation Depth with Corrections
for Outliers in Western States................................................................ 9-20

9.18(a) Log-Linear Regressions of Irrigation Depth Using All Observations in
Eastern and Central States..................................................................... 9-21

9.18(b) Log-Linear Regressions of Irrigation Depth Using All Observations in
Western States...................................................................................... 9-22

9.19(a) Log-Linear Regressions of Irrigation Depth with Corrections for Outliers
in Eastern and Central States ................................................................ 9-22

9.19(b) Log-Linear Regressions of Irrigation Depth with Corrections for Outliers
in Western States.................................................................................. 9-23

9.20 Comparison of Predictive Properties of Linear Models of Irrigation
Depth................................................................................................... 9-24

9.21 Comparison of Predictive Properties of Log-Linear Models of
Irrigation Depth..................................................................................... 9-25

9A.1 Linear Regression of Per Capita Public Supply Net Deliveries in
Arkansas Counties................................................................................ 9-26

9A.2 Log-Linear Regression of Per Capita Public Supply Net Deliveries in
Arkansas Counties................................................................................ 9-27

9A.3 Linear Regression of Combined Manufacturing Withdrawals and
Deliveries in Arkansas Counties............................................................. 9-28

9A.4 Log-Linear Regression of Combined Manufacturing Withdrawals and
Deliveries in Arkansas Counties ............................................................ 9-29

9A.5 Linear Regression of Per Unit Irrigation Withdrawals (in/yr) in Arkansas
Counties............................................................................................... 9-30

9A.6 Log-Linear Regression of Per Unit Irrigation Withdrawals in Arkansas
Counties............................................................................................... 9-31

9A.7 Linear Regression Model of Net Per Capita Public Supply Deliveries in
Kansas Counties................................................................................... 9-32

9A.8 Log-Linear Regression Model of Net Per Capita Public Supply
Deliveries in Kansas Counties................................................................ 9-33

9A.9 Linear Regression Model of Per Employee Manufacturing Use in
Kansas Counties................................................................................... 9-34

9A.10 Log-Linear Regression Model of Per Employee Manufacturing Use in
Kansas Counties................................................................................... 9-35

9A.11 Linear Regression Model of Gross Irrigation Depth in Kansas Counties........... 9-36

9A.12 Log-Linear Regression Model of Gross Irrigation Depth in Kansas
Counties............................................................................................... 9-37

9A.13 Linear Predictive Model of Per Capita Public Supply Deliveries in
Oregon Counties................................................................................... 9-38

9A.14 Log-Linear Predictive Model of Per Capita Public Supply Deliveries in
Oregon Counties................................................................................... 9-39

9A.15 Linear and Log-Linear Regression of Per Employee Manufacturing Use
in Oregon Counties............................................................................... 9-40

9A.16 Linear and Log-Linear Regressions of Gross Irrigation Depth in Oregon
Counties............................................................................................... 9-41

9A.17 Linear Regression of Per Capita Public Supply Deliveries in North
Carolina Counties.................................................................................. 9-42

9A.18 Log-Linear Regression of Per Capita Public Supply Deliveries in North
Carolina Counties.................................................................................. 9-43

9A.19 Linear Regression of Per Employee Manufacturing Use in North
Carolina Counties.................................................................................. 9-44

9A.20 Log-Linear Regression of Per Employee Manufacturing Use in North
Carolina Counties.................................................................................. 9-45

9A.21 Linear Regression of Gross Irrigation Depth in North Carolina Counties.......... 9-46

9A.22 Log-Linear Regression of Gross Irrigation Depth in North Carolina
Counties............................................................................................... 9-47

LIST OF FIGURES

3.1 Total Water Withdrawals versus Total Population............................................. 3-1

3.2 Total Withdrawals and Gross State Product...................................................... 3-3

3.3 Domestic Withdrawals and Per Capita Withdrawals.......................................... 3-5

3.4 Per Capita Withdrawals versus Median Family Income..................................... 3-6

3.5 Self-Supplied Industrial Withdrawals and Manufacturing Employment................ 3-7

3.6 Employment in Primary Metal Industries versus Per-Employee
Self-Supplied Industrial Withdrawals......................................................... 3-8

3.7 Total Irrigation Withdrawals and Irrigated Acres (USGS).................................. 3-9

3.8 Total Off-Stream Withdrawals and Thermoelectric Withdrawals...................... 3-11

3.9 Withdrawals Per Unit of Thermoelectric Production: 1950-1995..................... 3-12

3.10 Thermoelectric Withdrawals versus Thermoelectric Production:
1950-1995............................................................................................. 3-12

3.11 Total Off-Stream Withdrawals by Source....................................................... 3-14

4.1 Distribution of Total (mgd) and Per Capita (gpcd) Withdrawals by State,
1995........................................................................................................ 4-3

4.2 Change in Total Withdrawals (mgd) by State: 1960-1995................................. 4-6

4.3 Change in Total Withdrawals (mgd) by State: 1980-1995................................. 4-8

4.4 Distribution of Public Supply (mgd) and Per Capita (gpcd)
Withdrawals, 1995................................................................................. 4-11

4.5 Change in Public Supply Withdrawals (mgd), 1980-1995............................... 4-15

4.6 Distribution of Self-Supplied Industrial (mgd) and Per
Mining/Manufacturing Employee (gped) Withdrawals
(including commercial and mining), 1995................................................. 4-18

4.7 Changes in Self-Supplied Industrial Withdrawals (mgd), 1980-1995............... 4-20

4.8 Distribution of Irrigation Withdrawals (bgd) and Gross Irrigation Depth
(feet/acre/year): 1995............................................................................. 4-26

4.9 Changes in State Irrigation Withdrawals (mgd): 1980-1995 ............................ 4-31

4.10 Distribution of Thermoelectric (mgd) and Per Unit (gallons/kWh)
Withdrawals, 1995 ................................................................................ 4-35

4.11 Change in Thermoelectric Withdrawals (mgd), 1960-1980.............................. 4-37

4.12 Change in Thermoelectric Withdrawals (mgd), 1980-1995.............................. 4-40

5.1(a) Total Public Withdrawals versus Total Population: 1950-1995........................ 5-12

5.1(b) Natural Logarithm of Total Public Withdrawals versus Natural Logarithm
of Total Population: 1950-1995.............................................................. 5-13

5.2(a) Total Thermoelectric Withdrawals versus Total Thermoelectric
Generation: 1960-1995.......................................................................... 5-52

5.2(b) Natural Logarithm of Total Thermoelectric Withdrawals versus
Natural Logarithm of Total Thermoelectric Generation: 1960-1995.......... 5-52

5.3 Histogram of Unit Thermoelectric Withdrawals: 1960-1995 ........................... 5-58

6.1 Actual versus Predicted Values from Linear Model IA (mgd): 1985-1995......... 6-7

6.2 Effects of Data Outliers on Six Model Coefficients in Model IA......................... 6-8

6.3 Effects of Data Outliers on Three Model Coefficients in Model IA..................... 6-8

6.4 Plot of Predicted versus Actual Values from Model IB.................................... 6-11

6.5 Effect of Outliers on Regression Coefficients in Model IB................................ 6-12

6.6 Effects of Binary Outlier Variables on Model IC Coefficients........................... 6-16

6.7 Effects of Binary Outlier Variables on Model ID Coefficients........................... 6-20

6.8 Effects of Outliers on Regression Coefficients Model IID................................ 6-31

7.1 Absolute Percentage Errors versus Actual Per Capita Public-Supply
Withdrawals: 1980 Backcast.................................................................... 7-8

7.2 Percent Error versus Actual Per Employee Use: 1980 Backcast...................... 7-12

7.3 Percent Error versus Actual Irrigation Depth in Backcast for Western
States: 1980 .......................................................................................... 7-17

7.4 Percent Error versus Actual Irrigation Depth in Backcast for Eastern
States: 1980........................................................................................... 7-19

7.5 Percent Error versus Actual Thermoelectric Use Per Unit for 1980
Backcast (excluding Washington State) .................................................. 7-23

8.1 Total (Net) Public Supply Deliveries as a Function of Population Served........... 8-5

8.2 Log of Total (Net) Deliveries versus Log of Population Served.......................... 8-5

8.3 Absolute Percentage Error (APE) versus Per Capita Public Supply Use
for 408 Observations with Errors Greater than 100 Percent..................... 8-11

8.4(a) Manufacturing Water Use versus Employment................................................ 8-15

8.4(b) Log Manufacturing Use (in 1,000s gal.) versus Log Employment..................... 8-16

8.5(a) Irrigation Withdrawals versus Irrigated Area: All Counties............................... 8-23

8.5(b) Log Irrigation Withdrawals (mgd) versus Log Irrigated Area:
All Counties ........................................................................................... 8-23

8.6(a) Irrigation Withdrawals versus Irrigated Area: Western Counties....................... 8-24

8.6(b) Log Irrigation Withdrawals (mgd) versus Log Irrigated Area:
Western Counties................................................................................... 8-24

8.7(a) Irrigation Withdrawals versus Irrigated Area: Eastern Counties........................ 8-25

8.7(b) Log Irrigation Withdrawals (mgd) versus Log Irrigated Area: Eastern
Counties................................................................................................. 8-25

ACKNOWLEDGEMENTS

Numerous individuals from government agencies, non-governmental organizations, and universities assisted us during this research endeavor.

We first wish to thank the sponsors of this study, the U.S. Geological Service Competitive Grants Program and Southern Illinois University Carbondale. Dr. Richard Sparks, Director, Illinois Water Resources Center, served as the contracting officer for this study. He and his staff provided information and assistance at several important points during the research. The Department of Geography, and Department of Economics provided matching funds and release time for Professor Ben Dziegielewski and Professor Subhash Sharma, and office space and equipment for the project researcher, graduate assistants, and student workers.

Many of the USGS state and regional water-use coordinators took the time to share their knowledge of the water-use inventory process, searched their archived files to verify water-use data from past inventories, and commented on the design of several key components of the research. Specifically we would like to acknowledge the assistance we received from: Frank Amundson, Don Arvin, Charles Avery, Lisa Bratton, David Burt, Aimee Downs, Julia Fanning, Ed Fischer, Terrance Holland, Marilee Horn, Susan Hutson, Joan Kenny, Ron Lane, Kristin Linsey, Pam Lombard, Russell Ludow, Debbie Lumina, Carol Luukkonen, Dee Lurry, Richard Marella, Will Mooty, John Nawyn, Kathleen Rowland, Bill Templin, Bob Tortorelli, and Judith Wheeler.

Special thanks to Kurt Keeley, Data Base Manager for the American Water Works Association, who generously shared his time and the data from the AWWA WATER/STAT Database. This invaluable collection of survey data was used to develop the weighted average water price variables used in this study.

Natalie Ko, Collection Manager for the EIA-767 Database, from the U.S. Department of Energy’s Energy Information Administration provided access to, and information about, the EIA data used to develop the thermoelectric water use models. Antione Smith, Information Specialist from the National Energy Information Center, provided links to diesel fuel and cooling tower data, and Tammy Heppner of EIA provided information on diesel fuel prices.

Virginia A. Manser, from the Cooling Technology Institute and J. Dean Lammering, Marketing Manager Cooling Water, Nalco Chemical Company provided assistance in locating cooling tower data.

Dick Kipp and Denise Green of the Brookens Library at the University of Illinois Springfield helped us to obtain some of the historical climatic data used in the study. Greg Lawrence of the Albert R. Mann Library of Cornell University assisted us by providing early editions of the Farm and Ranch Irrigation Survey that were used in calculating energy pumping costs for the irrigation model. Sandra Fitz of the Illinois State Library for helping to secure copies of EEI Statistical Yearbook that were not available locally. The librarians at Southern Illinois University’s Morris Library generously shared their expertise and helped us on numerous occasions. .

Noel Goellehon and William Quimby of the USDAs Economic Research Service responded to our inquiries regarding the availability of historical irrigation data. Gary Kennedy, of the Bureau of Economic Analysis provided information on mining employment data and clarified the differences in employment data collection procedures of the Census Bureau and BEA Regional Accounts Data. Robert Nagan of the National Climate Data Center helped us to locate and interpret some of the climatic data used in the water use models.

Dr. David Maidment and the Academy of Sciences/National Research Council Water Science and Technology Board Committee on USGS Water Resources Research were very helpful in providing feedback and evaluation of the accuracy of USGS data in different states and time periods, and also provided comments on the project’s overall design.

Several graduate assistants and undergraduate student workers participated in the research project. Rong Hai Sa prepared all of the background information in the grant proposal, wrote many of the bibliographic annotation, and organized the early phases of the investigation. Eddie Anderson and Sasmito Wibowo spent many, many hours in SIUC’s Morris Library, collecting state and county-level socioeconomic data, and entering this data into spreadsheets. Beatrice Moore and Michelle Zuro helped to prepare the final report document.

The research team would also like to take this opportunity to acknowledge that we take full responsibility for any errors in the reproduction and use of the data received from the sources listed above.