Office of Ground Water

Guidelines for Preparation of State 

Water-Use Estimates for 2005

Techniques and Methods Book 4, Chapter E1

U.S. Department of the Interior

U.S. Geological Survey

Guidelines for Preparation of State 

Water-Use Estimates for 2005

Compiled by Susan S. Hutson

Techniques and Methods Book 4, Chapter E1

U.S. Department of the Interior

U.S. Geological Survey

Office of Ground Water
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

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Suggested citation:

Hutson, S.S., compiler, 2007, Guidelines for preparation of State water-use estimates for 2005: U.S. Geological 

Survey Techniques and Methods Book 4, Chap. E1, 36 p., available on the World Wide Web at http://pubs.usgs.

gov/tm/2007/tm4E1

 
Contents

Abstract...........................................................................................................................................................1

Introduction ....................................................................................................................................................1

Purpose and Scope ..............................................................................................................................2

Acknowledgments................................................................................................................................2

Water-Use Compilation Requirements for 2005........................................................................................2

Water-Use Categories and Data Elements.......................................................................................3

Units of Measurement..........................................................................................................................3

Aggregation Levels...............................................................................................................................3

Aggregate Water-Use Data System Database................................................................................3

Documentation......................................................................................................................................4

Compilation Methods ....................................................................................................................................4

General Methodologies and Techniques..........................................................................................4

Internet Resources...............................................................................................................................5

Quality Assurance and Quality Control .............................................................................................5

Standard Industrial Classification Coding System..........................................................................5

Public Supply..................................................................................................................................................6

Data Elements........................................................................................................................................6

Mandatory.....................................................................................................................................6

Optional..........................................................................................................................................6

Sources of Information ........................................................................................................................6

Agencies or Other Entities .........................................................................................................7

Internet Resources......................................................................................................................7

Compilation Techniques.......................................................................................................................7

Water Withdrawals .....................................................................................................................8

Per Capita Use Coefficients .......................................................................................................9

Population Served ......................................................................................................................9

Domestic Deliveries...................................................................................................................10

Estimating Domestic Deliveries Using Population Served 

and a Coefficient .................................................................................................10

Estimating Domestic Deliveries as a Percent of Total Public-Supply 

Water Use.............................................................................................................11

Self-Supplied Domestic ..............................................................................................................................11

Data Elements......................................................................................................................................11

Mandatory...................................................................................................................................11

Optional........................................................................................................................................11

Sources of Information ......................................................................................................................11

Agencies or Other Entities .......................................................................................................11

Internet Resources....................................................................................................................12

Compilation Techniques.....................................................................................................................12

 iii
Industrial........................................................................................................................................................13

Data Elements......................................................................................................................................13

Mandatory...................................................................................................................................13

Mandatory but Null Values Allowed.......................................................................................13

Optional........................................................................................................................................13

Sources of Information ......................................................................................................................13

Agencies or Other Entities .......................................................................................................13

Internet Resources....................................................................................................................13

Compilation Techniques.....................................................................................................................14

Water Withdrawals ...................................................................................................................14

Water-Use Coefficients.............................................................................................................15

Allocation of Water Withdrawals by Source ........................................................................15

Irrigation........................................................................................................................................................15

Data Elements......................................................................................................................................16

Mandatory...................................................................................................................................16

Mandatory but Null Values Allowed.......................................................................................16

Optional........................................................................................................................................16

Sources of Information ......................................................................................................................16

Agencies or Other Entities .......................................................................................................16

Internet Resources....................................................................................................................16

Compilation Techniques ....................................................................................................................17

Reported Data ............................................................................................................................18

Surveys and Personal Contact ................................................................................................18

Estimates of Crop Water Needs ..............................................................................................19

Statistical Sampling...................................................................................................................19

Allocation of Withdrawals by Source ....................................................................................19

Acres Irrigated by System Type ..............................................................................................19

Golf Course Irrigation................................................................................................................20

Thermoelectric Power................................................................................................................................20

Data Elements......................................................................................................................................20

Mandatory...................................................................................................................................21

Optional........................................................................................................................................21

Sources of Information ......................................................................................................................21

Agencies or Other Entities .......................................................................................................21

Internet Resources....................................................................................................................22

Compilation Techniques.....................................................................................................................22

References....................................................................................................................................................23

Supplemental Information..........................................................................................................................25

Coding Forms.......................................................................................................................................25

Mandatory Data Elements for County ....................................................................................25

Data Elements for County.........................................................................................................26

Data Elements for Aquifer........................................................................................................27

Data Elements for Eight-Digit Hydrologic Unit Code............................................................28

iv 
Conversion Factors and Abbreviations

Multiply By To obtain

Length

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 43,560 square feet (ft2)

acre 4,047 square meter (m2)

acre-foot (acre-ft) 1,233 square hectometer (hm2) 

acre-foot per day (acre-ft/d) 0.3259 hectare (ha)

acre-foot per acre (acre-ft/acre) 3,047 cubic meter per hectare (m3/ha) 

Volume

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3) 

gallon (gal) 3.785 cubic decimeter (dm3) 

million gallons (Mgal) 3,785 cubic meter (m3)

cubic mile (mi3) 4.168 cubic kilometer (km3) 

acre-foot (acre-ft) 1,233 cubic meter (m3)

acre-foot (acre-ft) 0.001233 cubic hectometer (hm3) 

Flow rate

acre-foot per day (acre-ft/d) 0.01427 cubic meter per second (m3/s)

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year (m3/yr)

acre-foot per year (acre-ft/yr) 0.001233 cubic hectometer per year (hm3/yr)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

gallon per day (gal/d) 0.003785 cubic meter per day (m3/d)

gallon per day per square mile

 [(gal/d)/mi2]

0.001461 cubic meter per day per square

kilometer [(m3/d)/km2]

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

million gallons per day per square

mile [(Mgal/d)/mi2]

1,461 cubic meter per day per square

kilometer [(m3/d)/km2]

inch per hour (in/h) 0 .0254 meter per hour (m/h)

inch per year (in/yr) 25.4 millimeter per year (mm/yr)

mile per hour (mi/h) 1.609 kilometer per hour (km/h) 

Mass

pound (lb) 453.6 gram (g)

Energy

gigawatt-hour (GWh) 1,000 megawatt-hour (kWh)

kilowatt-hour (kWh) 3,412 British thermal unit (Btu)

megawatt 56,920 British thermal unit per minute (Btu/min)

megawatt 1,000,000 watts

AWUDS — Aggregated Water Use Data System

CHP—Combined Heat and Power

CWS—Community Water System

GWh—Gigawatt-hour

HUC—Hydrologic Unit Code

NAICS—North American Industrial Classification System

NPDES—National Pollutant Discharge Elimination System

NWUIP—National Water Use Information Program

QA/QC—Quality Assurance/Quality Control

SDWIS —Safe Drinking Water Information System

SIC—Standard Industrial Classification 

USEPA—U.S. Environmental Protection Agency

USGS—U.S. Geological Survey

Additional abbreviations used in this report

   
Glossary

Water-use terminology has changed in the series of wateruse circulars prepared at 5-year intervals. The term water use, 

as initially used in the report for 1950, meant withdrawals of 

water; in the report for 1960, the term was redefined to include 

consumptive use of water as well as withdrawals. With the 

beginning of the U.S. Geological Survey National Water Use 

Information Program in 1978, the term was again redefined 

to include withdrawals plus deliveries from public suppliers. 

In the water-use circular for 2000, water use was defined as 

it was initially used in 1950 as withdrawals of water. For the 

2005 circular, water use was defined as water withdrawals plus 

deliveries. The following terms are referenced in the text and 

are part of the water-use circular series.

A

aquaculture water use Water used in the production of 

organisms that live in water within a confined space and under 

controlled feeding, sanitation, and harvesting procedures, and 

establishments primarily engaged in hatching fish and in operating fishing preserves. See also commercial water use, fish 

farms, and fish hatcheries.

aquifer A geologic formation, group of formations, or part of 

a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs. 

B

blowdown The continuous or intermittent discharge, or 

purging, of a small amount of circulating water, such as in a 

boiler. Blowdown normally is expressed as a percentage of the 

water being circulated. Its purpose is to prevent an increase in 

the concentration of solids in the water because of evaporation. 

C

capacity The average amount of water circulating in the 

cooling system of a thermoelectric power plant, usually 

expressed in gallons per minute.

closed-loop cooling system A cooling system in which water 

is withdrawn, circulated through heat exchangers, then cooled 

and recycled. Subsequent withdrawals are used to replace 

water lost to evaporation, blowdown, drift, and leakage.

commercial water use Water used for motels, hotels, restaurants, office buildings, other commercial facilities, and institutions. The water may be obtained from a public supply or may 

be self-supplied. In previous compilations, commercial water 

use included water use by fish hatcheries. See also aquaculture 

water use, public-supply water use, and self-supplied water. 

consumptive use The part of water withdrawn that is evaporated, transpired, incorporated into products or crops, consumed 

by humans or livestock, or otherwise removed from the immediate water environment. Also referred to as water consumed. 

conveyance loss Water that is lost because of leakage or 

evaporation while in transit through a pipe, canal, conduit, 

or ditch. Leakage from an irrigation ditch may percolate to a 

ground-water source and be available for further use. 

cooling system Equipment that is used for cooling purposes, 

such as condensers at power plants or factories. Includes water 

intakes and outlets, cooling towers, and cooling ponds.

cooling-system type See closed-loop cooling system and 

once-through cooling system.

D

deliveries Water distributed by public-water suppliers for 

domestic, commercial, industrial, or thermoelectric-power uses. 

desalination Separation of water from salts and minerals 

using thermal and membrane processes. Sources of water are 

brackish ground water, brackish surface water, and seawater. 

See also freshwater and saline water.

dewatering The removal of water through draining or pumping to lower the water table for mining or agriculture. 

dissolved solids A measure of the dissolved minerals and 

organic matter in water, usually expressed in milligrams per 

liter (mg/L). Water containing 1,000 mg/L or more dissolved 

solids is considered saline for all purposes except public 

supply in this report. See also desalination.

domestic deliveries Water provided to domestic users from 

a public supply.

domestic water use Water used for household purposes, 

such as drinking, food preparation, bathing, washing clothes 

and dishes, flushing toilets, and watering lawns and gardens. 

Also called residential water use. The water may be obtained 

from a public supply or may be self-supplied. See also publicsupply water use and self-supplied water. 

drift Fine water droplets blown out of a cooling tower 

along with exhaust air, usually expressed as a percentage of 

water circulated. 

E

evaporation Process by which water is changed from a liquid into a vapor. See also evapotranspiration and transpiration. 

evapotranspiration Water that is vaporized because of 

evaporation from the soil or plant transpiration. See also 

evaporation and transpiration. 

F

fish farms Facilities that produce finfish or shellfish under 

controlled feeding, sanitation, and harvesting procedures for 

commercial purposes. Water use by fish farms is included in 

the aquaculture category. See also aquaculture water use and 

fish farms.

finished water Water that is filtered or treated. See also raw 

water and water treatment.

vi 
freshwater Water that contains less than 1,000 mg/L dissolved 

solids. Generally, water with more than 500 mg/L dissolved 

solids is undesirable for drinking and many industrial uses. 

See also desalination and saline water.

G

gigawatt-hour (GWh) A unit of energy equivalent to 1 thousand megawatt-hours or 1 billion watt-hours. 

ground water All subsurface water, distinct from surface 

water. Specifically, that part of the subsurface water in the 

saturated zone, which is a zone where all voids are filled 

with water.

H

hydroelectric power water use The use of water in the generation of electricity at plants where the turbine generators are 

driven by falling water. 

hydrologic cataloging unit An eight-digit cataloging unit 

that identifies a geographic area representing part or all of a 

surface drainage basin, a combination of basins, or a distinct 

hydrologic feature. Sometimes known as a watershed.

I

industrial water use Water used for industrial purposes 

such as fabrication, processing, washing, and cooling, and 

includes such industries as steel, chemical and allied products, 

paper and allied products, smelting, and petroleum refining. 

The water may be obtained from a public supply or may be 

self-supplied. See also public-supply water use and selfsupplied water. 

instream use Water that is used within a stream channel for 

such purposes as hydroelectric power generation, navigation, 

water-quality improvement, fish propagation, and recreation. 

Sometimes called nonwithdrawal use or in-channel use. 

irrigation district A cooperative, self-governing public 

corporation with definite geographic boundaries and taxing 

power. Its function is to obtain and distribute water for irrigation of lands within the district.

irrigation system Equipment used to distribute water to 

crops or other irrigated lands. Irrigation systems are grouped 

into the following three broad categories:

microirrigation An irrigation system that wets only a 

discrete part of the soil surface near the plant by means 

of applicators operated under low pressure. The applicators 

can be placed on or below the surface of the ground 

or can be suspended from supports. Subsurface systems 

that control the height of the water table are included in 

this category.

sprinkler An irrigation system in which water is applied 

by means of perforated pipes or nozzles operated under 

pressure to form a spray pattern.

surface Irrigation by means of flood, furrow, or gravity. 

Flood irrigation is the application of irrigation water in 

which the entire soil surface is covered by ponded water. 

Furrow is a partial surface-flooding method of irrigation 

in which water is applied in furrows or rows of sufficient 

capacity to contain the design irrigation stream. Gravity 

is an irrigation method in which water is not pumped, but 

flows in ditches or pipes and is distributed by gravity.

irrigation water use Application of water on lands to assist 

in the growing of crops and pastures or to maintain vegetative 

growth on recreational lands such as parks and golf courses. 

Includes water applied for pre-irrigation, frost protection, 

chemical application, leaching salts from the root zone, and 

dust suppression, as well as water lost in conveyance. Also 

includes irrigation for cemeteries, turf farms, and other landscaped areas but does not include domestic lawns and gardens, 

which are included in the domestic water-use category.

K

kilowatt-hour (kWh) A unit of energy equivalent to 

1,000 watt-hours.

L

livestock water use Water for livestock watering, feedlots, 

dairy operations, and other on-farm needs. Livestock 

includes cattle, sheep, goats, hogs, poultry, horses, and furbearing animals.

M

makeup water The water pumped into a closed-loop 

cooling system to replace the circulating water lost by 

evaporation, drift, blowdown, and leakage. Makeup water 

usually is expressed as a percentage of the total amount of 

water circulated. 

mining water use Water used for the extraction of naturally 

occurring minerals including solids, such as coal and ores; 

liquids, such as crude petroleum; and gases, such as natural 

gas. Also includes uses associated with quarrying, well operations, milling, and other preparations customarily done at a 

mine site or as part of a mining activity. Mining water use 

does not include water used in processing, such as smelting, 

refining petroleum, or slurry pipeline operations, which are 

included in industrial water use.

N

North American Industry Classification System (NAICS) codes

Three-digit codes established in 1997 by the Office of 

Management and Budget in cooperation with its counterparts 

in Canada and Mexico. NAICS are used in the classification 

of establishments by type of activity in which they are 

engaged, thus enabling comparison of industries from the 

three countries. NAICS replaces the Standard Industrial 

Classification (SIC) system. See also Standard Industrial 

Classification (SIC) codes.

 vii
O

offstream use Water withdrawn or diverted from a surfacewater source for public-water supply, domestic, industry, irrigation, livestock, thermoelectric-power generation, and other 

uses. Sometimes called off-channel use or withdrawal. 

once-through cooling system A cooling system in which 

water is withdrawn, circulated through heat exchangers, and 

then returned to a body of water at a higher temperature. 

Also referred to as an open-loop cooling system.

P

per capita water use The average amount of water used 

per person during a standard time period, generally per day. 

Per capita use may be calculated based on total water use, 

public-supply water use, self-supplied domestic water use, or 

domestic deliveries from public supply.

pre-irrigation The application of water to cropland before 

planting to assure adequate soil moisture for crop germination 

and early plant growth.

public-supply water use Water withdrawn by public and 

private water suppliers that furnish water to at least 25 persons 

or have a minimum of 15 connections. Public suppliers provide water for a variety of uses, such as domestic, commercial, 

industrial, thermoelectric power, and public use. See also 

domestic water use, industrial water use, thermoelectric-power 

water use, and public water use. 

public water use Water provided by a public supply for such 

uses as firefighting, street washing, water treatment, municipal 

buildings, parks, and swimming pools. See also public-supply 

water use. 

R

raw water Water that has not been filtered or treated before 

use. See also finished water and water treatment. 

reclaimed wastewater Wastewater-treatment plant effluent 

that has been diverted for beneficial use before it reaches a 

natural waterway or aquifer. 

recycled water Water that is used more than once after withdrawal and before it returns to the natural hydrologic system. 

See also reclaimed water. 

return flow Water that reaches a ground-water or surfacewater source after it is released from the point of use, and thus 

becomes available for further use. 

reuse Use of water that has undergone wastewater treatment 

and is delivered to a user as reclaimed wastewater. 

See also reclaimed wastewater, recycled water, and 

wastewater treatment. 

S

saline water Water that contains 1,000 mg/L or more dissolved solids. For public supply, water that requires desalination or dilution to make it potable is considered saline. See 

also desalination and freshwater.

self-supplied water Water that is withdrawn directly from a 

ground-water or a surface-water source by a user, as opposed 

to water that is delivered by a public supplier. 

Standard Industrial Classification (SIC) codes Four-digit 

codes established by the Office of Management and Budget, 

last revised during 1987, and used in the classification of 

establishments by type of activity in which they are engaged. 

SIC codes are being replaced by NAICS codes. See also North 

American Industry Classification System codes.

surface water An open body of water, such as a stream, 

lake, or reservoir. 

T

thermoelectric-power water use Water used in the process 

of generating electricity with steam-driven turbine generators. 

The water may be obtained from a public supply or may be 

self-supplied. See also public-supply water use and selfsupplied water. 

transpiration Process by which water that is absorbed 

by plants, usually through the roots, is evaporated into the 

atmosphere from the plant surface. See also evaporation and 

evapotranspiration. 

W

wastewater treatment Removal or reduction of solids, 

pathogens, or other undesirable constituents from wastewater. 

See also reclaimed water and recycled water. 

water transfer Conveyance of water from one area to 

another using natural or human made channels. 

water treatment Processes such as filtration and disinfection 

of water prior to delivery and use.

water-use coefficient A factor or ratio used to estimate a 

quantity of water used based on a related quantity. Examples 

of water-use coefficients include daily per capita water use, 

consumptive crop irrigation requirements, livestock water 

requirements, per employee water use, and per unit of product 

water use.

withdrawal The removal of ground water or surface water 

from the natural hydrologic system for uses including public 

supply, commercial, domestic, industry, irrigation, mining, 

livestock, aquaculture, and thermoelectric-power generation. 

See also offstream use.

viii 
Abstract

The U.S. Geological Survey (USGS) has estimated the 

use of water in the United States at 5-year intervals since 

1950. This report describes the water-use categories and data 

elements required for the 2005 national water-use compilation 

conducted as part of the USGS National Water Use Information Program. The report identifies sources of water-use 

information, provides standard methods and techniques for 

estimating water use at the county level, and outlines steps for 

preparing documentation for the United States, the District of 

Columbia, Puerto Rico, and the U.S. Virgin Islands. 

As part of this USGS program to document water use 

on a national scale for the year 2005, estimates of water 

withdrawals for the categories of public supply, self-supplied 

domestic, industrial, irrigation, and thermoelectric power 

at the county level are prepared for each State using the 

guidelines in this report. Estimates of water withdrawals for 

aquaculture, livestock, and mining are prepared for each State 

using a county-based national model, although study chiefs in 

each State have the option of producing independent county 

estimates of water withdrawals for these categories. Estimates 

of deliveries of water from public supplies for domestic use 

by county also will be prepared for each State for 2005. As a 

result, domestic water use can be determined for each State by 

combining self-supplied domestic withdrawals and publicly 

supplied domestic deliveries. Fresh ground-water and surfacewater estimates will be prepared for all categories of use; and 

saline ground-water and surface-water estimates by county 

will be prepared for the categories of public supply, industrial, 

and thermoelectric power. Power production for thermoelectric power will be compiled for 2005. If data are available, 

reclaimed wastewater use will be compiled for the industrial 

and irrigation categories. 

Optional water-use categories are commercial, hydroelectric power, and wastewater treatment. Optional data elements are public-supply deliveries to commercial, industrial, 

and thermoelectric-power users; consumptive use; irrigation 

conveyance loss; and number of facilities. Aggregation of 

water-use data by eight-digit hydrologic cataloging unit and 

by principal aquifer also is optional.

Water-use data compiled by the States will be stored in 

the USGS Aggregate Water-Use Data System (AWUDS). This 

database is a comprehensive aggregated database designed to 

store both mandatory and optional data elements. AWUDS 

contains several routines that can be used for quality assurance 

and quality control of the data, and produces tables of wateruse data compiled for 1985, 1990, 1995, and 2000. 

Introduction 

The U.S. Geological Survey (USGS) has compiled and 

published estimates of water use for the Nation at 5-year 

intervals since 1950. During 1977, Congress provided funding 

for the USGS to establish the National Water Use Information 

Program (NWUIP), which is a cooperative effort with States 

to collect reliable and uniform water-use information. USGS 

circulars entitled Estimated Use of Water in the United States 

present data collected for each State in the United States, the 

District of Columbia, Puerto Rico, and the U.S. Virgin Islands 

(MacKichan, 1951, 1957; MacKichan and Kammerer, 1961; 

Murray, 1968; Murray and Reeves, 1972, 1977; Solley and 

others 1983, 1988, 1993, 1998; and Hutson and others, 2004). 

Estimates of fresh ground-water and surface-water 

withdrawals by county are mandatory for the categories of 

public-supply, self-supplied domestic, industrial, irrigation, and 

thermoelectric power. Estimates of saline ground-water and 

surface-water withdrawals by county are mandatory for the categories of public supply, industrial, and thermoelectric power. 

Estimates of reclaimed wastewater use by county are mandatory for the irrigation and industrial categories, but null values 

are allowed if there is an uncertainty about the use of reclaimed 

wastewater in the county. County estimates for each State for 

these categories will be prepared for each State using a countybased national model, although study chiefs in each State have 

the option of producing independent county estimates of water 

withdrawals for these categories (John Lovelace, U.S. Geological Survey, written commun., 2005). Guidelines for estimating 

aquaculture, livestock, and mining water use can be accessed 

at http://pubs.usgs.gov/tm/2005/tm4A4/. Aggregating groundGuidelines for Preparation of State 

Water-Use Estimates for 2005

Compiled by Susan S. Hutson
water or surface-water withdrawals by eight-digit hydrologic 

cataloging unit is optional for all categories (Kenny, 2004). 

Aggregating ground-water withdrawals by principal aquifers 

(U.S. Geological Survey, 2003) also is optional. Estimating 

ground-water and surface-water withdrawals for the aquaculture, livestock, and mining categories is mandatory for all 

States. Commercial, hydroelectric-power, and wastewatertreatment categories are optional for all States. This report 

describes guidelines for estimating data for the mandatory 

categories of public supply, self-supplied domestic, industrial, 

irrigation, and thermoelectric power.

In some States, governmental agencies, universities, or 

private organizations collect water-use information for some 

categories. For other categories, water-use information is collected from multiple sources or estimated using coefficients 

and ancillary data. Water-use study chiefs in each USGS Water 

Science Center are familiar with the availability and reliability 

of information in their own State and work with their cooperators to produce reliable estimates of water use. This information may be electronically stored in databases developed by an 

individual State or by the USGS. 

The Aggregate Water-Use Data System (AWUDS) is 

a USGS database that is specifically designed to store and 

manipulate the aggregate water-use information compiled for 

the 5-year reports. AWUDS also is capable of storing annual 

aggregate water-use data compiled for the interval years 

between national compilations. 

Purpose and Scope

The purpose of this report is to provide guidelines for 

preparation of State water-use estimates. Water-use categories, 

data elements, aggregation levels, and documentation requirements are defined for the 2005 national water-use compilation. This information is useful both to those who prepare the 

estimates and to those who use the data. 

The scope of the 2005 compilation has been modified 

from the 2000 compilation. The focus remains on preparing estimates of water withdrawals for the categories of 

public supply, self-supplied domestic, industrial, irrigation, 

and thermoelectric power in each State with the addition of 

domestic deliveries from public supply, thermoelectric-power 

generation, and reclaimed wastewater use for the industrial 

and irrigation categories. Combined, public-supply domestic 

delivery and self-supplied domestic withdrawal data determine 

total domestic use. Combined, power-generation data and 

thermoelectric-power withdrawals provide a range of powerproduction coefficients for use in evaluating the quality of the 

data. Reclaimed wastewater data gage the scale of use of this 

secondary water source, and this information may be especially valuable in areas of constrained water availability. 

The following estimates are optional for the 

2005 compilation.

• Water withdrawals for commercial use

Instream use, offstream withdrawals, and associated 

power production for hydroelectric power

Wastewater-treatment water releases

Reclaimed wastewater use for commercial, thermoelectric-power, and wastewater-treatment purposes

Public-supply population served by source of supply

Consumptive use

Irrigation conveyance loss

Deliveries from public-water suppliers to commercial, 

industrial, thermoelectric-power users

Number of facilities 

Nevertheless, estimates for these categories may be compiled and stored in the AWUDS database as can the optional 

data aggregated by eight-digit hydrologic cataloging unit 

(described by Seaber and others, 1987) and principal aquifer 

(as described by Maupin and Barber, 2005). 

The USGS NWUIP, with support from the USGS Office 

of Ground Water, prepared the guidelines. The document is 

designed to complement the national water-use workshop that 

was held November 2005. The methods presented are general 

in nature and are not intended to replace more specific or 

detailed methodologies that may be used by some water-use 

study chiefs. Required documentation of the methodology 

used by each study chief is part of scientific protocol and is 

especially important for this study because data availability 

and reliability vary from State to State. Each USGS Water Science Center maintains documentation as a reference for current data and as a starting point for continued data collection.

Acknowledgments

This report was compiled from material developed over 

time by personnel from the USGS NWUIP and USGS Water 

Science Centers. Contributors to this text include Nancy L. 

Barber, Susan S. Hutson, Joan F. Kenny, Kristin S. Linsey, 

Deborah S. Lumia, and Molly A. Maupin.

Water-Use Compilation Requirements 

for 2005

Minimum requirements for the 2005 national compilation are designed to produce a more cost-effective product 

that meets the scientific priorities of the USGS and NWUIP. 

The modified national data model is not intended to limit any 

efforts to meet the needs of local programs and cooperators. 

Required and optional water-use categories and the associated 

data elements are summarized on the Coding Forms in the 

Supplemental Information section at the back of this report.

•

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•

•

•

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•

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   Guidelines for Preparation of State Water-Use Estimates for 2005
Water-Use Categories and Data Elements

For 2005, water-use data are required by county and are 

optional for eight-digit hydrologic cataloging unit and principal aquifer. Fresh ground-water and surface-water estimates 

will be prepared for the categories of public supply, selfsupplied domestic, industrial, irrigation, and thermoelectric 

power. Saline ground-water and surface-water estimates will 

be prepared for the categories of public supply, industrial, and 

thermoelectric power (once-through and closed-loop cooling systems). Irrigation may be reported either as total or as 

subcategories of crop and golf course irrigation. The choice 

of reporting a total or subcategories must be consistent for all 

counties in the State. Reclaimed wastewater use is a required 

data element for the industrial and irrigation categories. Zeros 

should be reported for counties where the delivery of reclaimed 

wastewater does not occur, but null values can be stored in 

AWUDS for counties where there is an uncertainty about the 

use of reclaimed wastewater. Compiling domestic deliveries 

from public supply and power generated by thermoelectric 

power plants by cooling type is required. Aquaculture (freshwater by source), livestock (freshwater by source), and mining 

(freshwater and saline water by source) are mandatory categories. Estimates of water withdrawals for these categories 

will be provided to the study chief for each county in the State 

by NWUIP. However, a study chief may decide not to use the 

nationally generated numbers but, instead, use independently 

estimated values for water withdrawals for the three categories.

Compiling total population served by public-water suppliers is required for each county. Once county population 

estimates are available from the U.S. Census Bureau, NWUIP 

will provide the data set to the study chief in a format that can 

be readily input into AWUDS. County self-supplied domestic-population in AWUDS is calculated automatically as the 

county population minus the county population served by 

public supply. 

Optional categories and data elements also are summarized in the coding forms in the Supplemental Information 

section at the back of this report. Data for these categories may 

be compiled and stored in the AWUDS database. Guidance for 

compiling data for the optional categories and data elements is 

available from the guidelines for 1995 (E. James Crompton and 

Wayne B. Solley, U.S. Geological Survey, written commun., 

March 27, 1995) and 2000 (Kenny, 2004). Population served 

by ground water and surface water; commercial, hydroelectricpower, and wastewater-treatment categories of use; deliveries 

from public suppliers for commercial, industrial, and thermoelectric-power purposes; consumptive use for commercial, 

self-supplied domestic, industrial, thermoelectric power (oncethrough and closed loop cooling systems), mining, livestock, 

irrigation (crop and golf course), and aquaculture categories of 

use; and irrigation conveyance loss are optional data elements. 

Compiling power production data for hydroelectric power; 

number of facilities for public supply, industrial, thermoelectric 

power, hydroelectric power, and wastewater treatment; and 

reclaimed-wastewater use for the commercial, public supply, 

mining, thermoelectric power (once-through and closed-loop 

cooling systems), and wastewater-treatment categories of use 

are optional. 

Units of Measurement

Water withdrawals are stored in AWUDS in million 

gallons per day. Population is stored in units of thousands of 

persons. Acres irrigated are stored in units of thousand acres. 

Power production is stored in units of gigawatt-hours, which 

is equivalent to 1 thousand megawatt-hours or 1 billion watthours. All values are stored with two places after the decimal 

point. A value of zero usage for a data element indicates either 

no usage or usage of less than 0.01 Mgal/d. A null value for 

reclaimed wastewater use indicates uncertainty as to the presence of the water-use activity in the county.

Aggregation Levels

Water withdrawals for the public-supply, irrigation, 

industrial, thermoelectric power, mining, livestock, and 

aquaculture categories will be compiled by county for each 

State. For this compilation, the District of Columbia, Puerto 

Rico, and the Virgin Islands are treated as States, and Alaska 

boroughs, Louisiana parishes, and Virginia independent cities 

are treated as counties. Refer to “Guidelines for Preparation 

of State Water-Use Estimates for 2000” at http://pubs.usgs.

gov/tm/2005/tm4A4/ for guidance for aggregating water use by 

principal aquifer. 

Aggregate Water-Use Data System Database

Water-use study chiefs are required to enter aggregate 

data by county for mandatory water-use categories into 

AWUDS except self-supplied domestic population, which will 

be calculated internally and then stored by AWUDS. Since 

1980, the USGS has electronically stored aggregate wateruse data. The AWUDS database was created during 1985 to 

store data aggregated by county or hydrologic cataloging unit. 

AWUDS was redesigned for 2000 and released as a personal 

computer-based system installed in each USGS Water Science Center and allowed for the storage of selected data by 

principal aquifer. AWUDS was updated for the 2005 compilation to accommodate the updated compilation requirements. 

AWUDS also is able to store the optional data elements by 

county, including selected ground-water categories by principal aquifer, and all the data elements by eight-digit hydrologic 

cataloging unit. 

In addition to meeting the storage requirements for the 

compilation every 5 years, AWUDS also can store water-use 

data for any other year. Within AWUDS, data are entered and 

edited interactively or imported from external files. AWUDS 

can generate tables by category of use or by county, eight-digit 

hydrologic cataloging unit, or principal aquifer. Summary 

Water-Use Compilation Requirements for 2005 
tables show entered data elements or provide calculated values 

for categories. Quality-assurance and quality-control (QA/QC) 

programs within AWUDS include checks for erroneous values, 

comparison of totals by area, and comparison of data between 

2 years. 

Documentation

Documentation of data sources and methodology is 

required as part of the 2005 compilation. Documentation corroborates the data that will be published in the USGS wateruse circular and provides a guideline for subsequent compilations. The water-use study chief determines the format for 

each State’s documentation. All documentation must include 

the following elements.

Sources of data and coefficients used

Agency and contact information

Methods, techniques, and coefficients used to collect or 

estimate data 

Location and types of data files 

Explanation of significant changes from the 2000 

water-use data 

Results of QA/QC on acquired or estimated data 

If the 2005 water-use estimates of values for the data elements differ substantially from those reported during 2000, 

possible explanations for these differences should be included 

in the documentation. For example, a major nuclear-fueled 

power plant may have started operation, several pulp and 

paper industries may have closed, or irrigation may have been 

encouraged or limited in an area of the State. Any information that can add to the understanding of water use in the State 

should be included in the documentation. 

Water-use study chiefs will transmit completed documentation in electronic form to the respective USGS regional 

water-use specialist. A standardized naming convention for 

the documentation file includes the ZIP code and the date. For 

example, for Alabama, the name of the documentation file will 

be “ALdocyymmdd.”

Compilation Methods

The compilation of water-use data for 2005 should begin 

with the review of the documentation, if available, from the 

previous compilations. Although the format of the documentation has changed with time, the documentation should provide 

the water-use study chief with a starting point for developing 

an approach and a time-task plan. The previous documentation 

should contain the location and types of electronic and paper 

water-use files; agency and contact information; sources of 

data; and methods, techniques, and coefficients used to collect 

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or estimate data. Several methods are described in each section 

of the guidelines. If needed, study chiefs are encouraged to 

investigate other methods outside of those suggested.

General Methodologies and Techniques

The availability of data, the year of the most recent data, 

and the completeness of the data can vary among States and 

among the counties within a State. Accessing the data for estimating water use can be as uncomplicated as asking agencies 

or organizations for the data reported to them or as involved 

as designing a survey to collect the data. When data are not 

readily available, for some categories, water-use data can be 

collected by either an inventory of all sites or a partial inventory of the water-use sites using several sampling techniques. 

Site-specific water-use data more commonly are available for 

public-supply, industrial, and thermoelectric-power facilities 

and less commonly available for self-supplied domestic, irrigation, aquaculture, livestock, and mining water-use sites. When 

site-specific data are not available, water-use estimates may be 

determined using ancillary data and a water-use coefficient. 

An inventory accounts for all of the individual sites and 

ancillary data in contrast to a partial inventory that queries 

selected water-use sites using several sampling criteria. Once 

an inventory has been developed, some or all of the users can 

be surveyed to determine water usage. Federal agencies cannot 

distribute surveys without meeting the requirements of the 

Paper Reduction Act of 1995 (U.S. Congress, 1995). Generally, the guidelines for developing a survey are as listed. 

Identify agencies with the authority or legal mandate to 

collect the data;

Identify the type of facilities information needed; 

Identify the agency and organization sources of facility 

information for the category of use;

Construct a master list of facilities; 

Decide on a sampling approach if not all users are to 

be surveyed; 

Create a survey form that is short and easy for the user 

to complete; 

Write a concise description of the requested data;

Provide a contact name and phone number for which to 

direct questions;

Provide a desired completion date; 

Include a statement of confidentiality;

Identify an agency or organization to cooperate in 

distributing the surveys; the entity may be different 

from the agency with the authority and legal mandate 

to collect the data;

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 Guidelines for Preparation of State Water-Use Estimates for 2005
Send survey forms by mail, fax, or e-mail; or conduct 

the survey by phone;

Develop a tracking process for receiving and managing 

the returned survey forms; and 

Implement a follow-up procedure for contacting facilities that do not respond by the requested time. 

A detailed discussion of methodology specific to each category occurs in the category sections.

To produce the most complete and defensible data for 

each State, the greatest effort and time are spent collecting 

information about the largest users and the largest categories 

of use in individual States. Compilation of accurate data for 

the largest public suppliers, industries, agricultural regions, 

and power plants produces State totals that are fairly reliable. 

As time and resources permit, data on smaller-volume water 

users also should be collected within each category.

Without site-specific data, water use often is estimated 

using a coefficient that represents a unit-use water requirement and number of units such as population served, number 

of employees, acres of cropland, or number of golf courses 

or golf holes. Some water-use coefficients already have been 

developed and are part of the technical literature or administrative and legislative documents for a State. If water-use 

coefficients are not available or perhaps no longer suitable, 

coefficients can be developed from a representative sample 

of typical users that are more pertinent to a specific facility, 

county, or State. The source of the coefficients, the source of 

the ancillary data, and the date they were accessed should be 

documented. 

A glossary of terms in the front of this report provides 

definitions of the mandatory data elements to be collected as 

part of the 2005 compilation. Some general hydrologic and 

water-use concepts also are included. 

Internet Resources

Numerous agencies and organizations are listed in this 

report as possible sources of information for compiling waterrelated data for the several categories of use. Many of these 

agencies and organizations maintain information and databases on the Internet. Specific Internet addresses are listed in 

this report as they appeared on the date last accessed. 

Quality Assurance and Quality Control

Errors can occur in both the compiled and entered data. 

QA/QC are scientific protocols implemented to ensure the 

quality of the water-use estimate. By definition, quality assurance is the program for the systematic monitoring and evaluation of the several aspects of a project to ensure that standards 

of quality are being met. Quality control is an aggregate of 

activities designed to ensure adequate data quality. AWUDS 

provides a system of QA/QC procedures to check for errors. 

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The following basic checks can be made during data compilation and after AWUDS data entry.

Use AWUDS quality-assurance programs to check for 

erroneous data and to compare State totals with principal aquifer or hydrologic unit totals by category.

Review spatial distribution of data using choropleth 

or other types of geographic information system 

(GIS) maps.

Compare 2005 data with those from the previous compilations years. Examine changes based on percentage 

change, statistical analysis, or general geographic patterns of use within a State.

Use sorting routines to check for possible errors in 

largest and smallest water withdrawals.

Examine calculated values such as per capita use and 

irrigation application rates.

Check county and State data for population served to 

ensure that they do not exceed total census populations. 

Much of the data that will be used in the compilation 

will be received from other entities. A preliminary QA/QC 

should be performed, if possible, before the data are integrated 

into the USGS analysis and database. The QA/QC should 

document the level of completeness, degree of accuracy, and 

amount of QA/QC given to the data by the entities from whom 

the data were received. The QA/QC should determine whether 

the data are based on a census enumeration or are statistically 

derived data, like the National Agricultural Statistics Service 

(NASS) data. Completeness of the data can be examined by 

determining, for example, if reported crop acreages include all 

crop acreages or just irrigated acreages; if irrigated acreages 

and water deliveries are reported for a management area of a 

particular agency, or for an entire county; or if some data are 

censored for privacy reasons. Additionally, any data obtained 

from surveys, questionnaires, or cooperator reports should be 

checked for reporting consistency (against former data) and 

consistency in reporting location over time; some site visits 

should be conducted, if possible; outliers in the data should be 

identified; and units of measurement should be verified. 

Standard Industrial Classification 

Coding System

The Standard Industrial Classification (SIC) coding 

system was developed to promote the comparability of establishment data describing several facets of the U.S. economy 

(Office of Management and Budget, 1987). The SIC coding 

system was intended to cover the entire field of economic 

activities—agriculture, forestry, fishing, hunting, and trapping; 

mining; construction; manufacturing; transportation, communications, electric, gas, and sanitary services; wholesale trade; 

retail trade; finance, insurance, and real estate; personal, busi-

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Compilation Methods   
ness, professional, repair, recreation, and other services; and 

public administration. The SIC coding system is based on the 

primary activity in which the industry is engaged. The structure of the classification makes it possible to tabulate, analyze, 

and publish industry data based on a two-digit major group, a 

three-digit industry group, or a four-digit industry code.

The USGS has assigned each four-digit industry code 

in the 1987 SIC manual (Office of Management and Budget, 

1987) to a water-use category. In some cases, a code may be 

listed under more than one water-use category. The SIC codes 

can be useful for assigning withdrawals to the public-supply, 

industrial, mining, and thermoelectric-power categories. A list 

of SIC codes by water-use category is shown at http://pubs.

usgs.gov/tm/2005/tm4A4/ (table 3).

A newer system of classification, the North American 

Industry Classification System (NAICS), went into effect in 

1997. The U.S. Census Bureau (U.S. Department of Commerce, 2000, 2002) published descriptions of the NAICS 

codes and correlation with SIC codes. USGS water-use study 

chiefs may continue to identify industries using SIC codes for 

the 2005 compilation. 

Public Supply

Public supply refers to water withdrawn from ground and 

surface sources by public and private water systems for use by 

cities, towns, rural water districts, mobile-home parks, Native 

American Indian reservations, and military bases. Public-supply facilities provide water to at least 25 persons or have a 

minimum of 15 service connections and are classified as SIC 

4941. Water withdrawn by public suppliers may be delivered 

to users for domestic, commercial, industrial, and thermoelectric-power purposes, as well as to other public-water suppliers. Public-supply water is used for public services (public 

uses)—such as pools, parks, and public buildings—or may be 

unaccounted (losses) because of system leaks or such nonmetered services as firefighting or the flushing of water lines. 

Some public-supply water may be used in the processes of 

water and wastewater treatment. Some public suppliers treat 

saline water before distributing the water. 

Public-supply deliveries for domestic purposes will be 

estimated for 2005 as described below. In addition, guidelines for estimating self-supplied domestic withdrawals are 

described in the Self-Supplied Domestic section of this report. 

Estimates of saline ground-water and surface-water withdrawals for public supply are mandatory for 2005. The definition 

of saline water for public supply has been changed from the 

previous one used in earlier circulars from water that contains 

1,000 mg/L or more of dissolved solids to water that has been 

treated to reduce the concentration of dissolved solids through 

the process of desalination or dilution. The criterion was 

changed because there had been little advantage or opportunity 

to measure dissolved solids and to compare the measurement 

to the 1,000 mg/L standard. 

Data Elements

The category of public supply consists of the following 

mandatory and optional data elements. Data for the optional 

elements may be compiled and entered into AWUDS, but 

will not be part of the national water-use analysis for 2005 as 

published in the water-use circular series. The optional data, 

however, will be available for other types of water studies. 

Mandatory

Ground-water withdrawals, freshwater, by county

Surface-water withdrawals, freshwater, by county

Ground-water withdrawals, saline water, by county

Surface-water withdrawals, saline water, by county 

Domestic deliveries, by county (also see Self-Supplied 

Domestic section in this report)

Total population served, by county

Optional

Population served by total ground water, by county

Population served by total surface water, by county

Commercial, industrial, and thermoelectric-power 

(once-through and closed-loop systems) deliveries, 

by county 

Number of facilities, by county

Reclaimed wastewater use, by county

Any data aggregated by hydrologic cataloging unit

Ground-water withdrawals, freshwater, by 

principal aquifer

Ground-water withdrawals, saline water, by 

principal aquifer

Population served, by principal aquifer 

Sources of Information

For each USGS Water Science Center, the documentation for the previous compilations should be the starting point 

for planning the data collection for the 2005 compilation. 

The previous documentation for the public-supply category 

may contain the location and types of electronic and paper 

files; agency and contact information; agency and Internet 

resources; and methods, techniques, and coefficients used to 

collect or estimate data. With this information, one should 

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 Guidelines for Preparation of State Water-Use Estimates for 2005
know where to begin to create or update a master list of 

public-supply systems and collect data on public-supply 

withdrawals, sources of water, and population served. 

Additional information concerning public-supply water use 

may be obtained from the following sources. Other sources 

of information may be available in each State.

Agencies or Other Entities

Possible contacts for public-supply water-use data are 

listed as follows. Water-use data from these sources can range 

from reported water withdrawals to coefficients and ancillary data that can be used to estimate water withdrawals and 

domestic deliveries. Multiple data sets can be used to determine the best estimates and provide QA/QC. 

Individual public suppliers

State agencies that administer water rights, allocate 

water to users, or collect water-use data

State agencies that enforce the Safe Drinking Water 

Act and issue permits for water discharge

State public health agencies

State agencies that regulate utility rates

State, regional, county or community planning, development or zoning agencies

State natural-resource agencies

Consulting firms

Internet Resources

Many agencies and other entities maintain public supply 

water-use information and databases on the Internet. Specific 

Internet addresses are listed as they appeared on the date 

last accessed. 

U.S. Census Bureau, accessed June 6, 2006, at <http://

www.census.gov/>

American FactFinder database, the U.S. Census 

Bureau’s online data source, containing information 

on population and housing, accessed June 6, 2006, 

at <http://factfinder.census.gov/>

U.S. Environmental Protection Agency (USEPA), 

accessed June 6, 2006, at <http://www.epa.gov/>

Safe Drinking Water Information System (SDWIS), 

access to data that States must report to USEPA as 

required by the Safe Drinking Water Act.

Safe Drinking Water Query Form, accessed June 6, 

2006, at <http://www.epa.gov/enviro/html/sdwis/

sdwis_query.html>

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Search the SDWIS database for selected public 

supply information. Includes data on water-system 

name, county, population served, and primary watersource type. Focus should be on community water 

systems that serve comparatively greater populations in the State. SDWIS also contains information 

on noncommunity systems that are further categorized according to type of population served during 

the day (transient or nontransient). 

Office of Ground Water and Drinking Water, accessed 

June 6, 2006, at <http://www.epa.gov/OGWDW/>

Water Discharge Permits, Permit Compliance 

System (PCS) database, accessed June 6, 2006, at 

<http://www.epa.gov/enviro/html/pcs/pcs_query_

java.html/>

Access to data regarding facilities holding National 

Pollutant Discharge Elimination System (NPDES) 

permits. Specify the facilities by using any combination of facility name, geographic location, SIC code, 

and chemicals.

American Water Works Association, accessed June 6, 

2006, at <http://www.awwa.org/>

Links to local Web sites and contacts, accessed 

June 6, 2006, at <http://www.awwa.org/sections/

SechomePage.cfm>

Links to information on individual public suppliers, accessed June 6, 2006, at <http://www.awwa.

org/community/links.cfm>

Association of State Drinking Water Administrators 

(ASDWA), accessed June 6, 2006, at <http://www.

asdwa.org/>

Links to a variety of Internet resources including a page with 

links for each State’s drinking water program pages and the 

primary State agency responsible for drinking water.

National Rural Water Association, accessed June 6, 

2006, at <http://www.nrwa.org/> Organizations 

whose membership rosters include public or private 

utilities, such as League of Municipalities or State 

rural water associations.

Compilation Techniques

Constructing a master list of public-supply systems is 

fundamental to all of the compilation techniques. A master 

list, at a minimum, consists of the names and locations of public-water suppliers, populations served, and sources of water. 

The information to build or update this list may be available 

from previous documentation, one or more State agencies, or 

USGS water-use databases. The USEPA SDWIS database is 

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Public Supply 
a secondary source containing information on public supplies 

obtained from the State agencies that administer water-quality 

regulations for drinking water. The SDWIS database includes 

information on the names and locations of systems, source of 

supply, location of water intakes, and population served for 

all community water systems (CWS), which are those serving at least 25 persons or 15 or more service connections on a 

year-round basis. SDWIS does not include any information on 

quantity of water withdrawn. In some cases, the State agencies 

providing the data to SDWIS may have more up-to-date and 

complete information than SDWIS. 

Water Withdrawals

Public-supply withdrawals are compiled for the county in 

which the withdrawals occur, although the water subsequently 

may be distributed and used elsewhere. State reporting programs and individual public-water suppliers are good sources 

of data. Individual State reporting agencies have varying criteria for obtaining public-supply water-use data; these criteria 

may be based on such permit requirements as size of system or 

magnitude of withdrawals. Return rates of the required surveys 

to the State reporting agency, as well as the amount of QA/QC 

review, also may vary from State to State. For these reasons, 

some needed public-supply system information may not have 

been collected by the State agency and, therefore, must be 

obtained directly from the public-supply system or be determined from other ancillary information. 

Study chiefs may survey public-water suppliers by telephone calls or visits to the systems. Mail surveys may be used 

if a State cooperator or other entity participates in the mailing, 

or if requirements of the 1995 Paper Reduction Act (U.S. 

Congress, 1995) are met. Usually, information can be obtained 

from a director of public works, city engineer, city clerk, 

bookkeeper, manager, or operator. The level of detail obtained 

depends on the availability of the information and the necessary 

resources available to collect the data. Useful information to 

request from these contacts includes the following list of items. 

Source(s) of water. Well information (local name or 

number, depth, location) and names of aquifers used 

for ground-water sources, names and locations of 

surface-water sources (streams, lakes, reservoirs), and 

sources of any purchased water. Some water suppliers 

use combinations of ground water, surface water, or 

purchased water.

Total withdrawals during 2005. Amounts of water 

pumped may have been measured by flowmeters or calculated using pump rates and number of hours pumped. 

The rate of withdrawal may be by day, month, or year.

Metering points. Water may be metered before treatment, during transport to another location, or as it is 

delivered to users. Knowing the metering point allows 

for the accounting of treatment or transit losses and 

avoids double counting of water.

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Type of treatment plant. Surface water usually 

requires more water for treatment processes, such as 

backwashing filters, than ground water does. If total 

reported water is finished rather than raw water, an 

amount or percentage of water for treatment should 

be added for systems with a great amount of watertreatment usage. 

Names of other connected water suppliers and 

amounts of water purchased or sold. Many water 

suppliers purchase and sell water.

Number of service connections by type. Numbers 

of active residential, commercial, industrial, or other 

meters may be used with a coefficient to estimate 

delivery amounts by customer types. Coefficients also 

may be derived from the number of meters, delivery 

volumes, and population or employment counts. Numbers of active residential meters, including single-family and multifamily housing, are useful for determining 

population served.

Amounts of water delivered for several purposes 

during 2005. Total water use for a public supply is 

accounted for through deliveries to other public supplies; domestic, commercial, industrial, and thermoelectric-power customers; and public use and losses. 

Delivery data can be used to develop water-use coefficients for estimating withdrawals for similar public 

suppliers. Total metered uses also can be subtracted 

from total withdrawals to determine amounts of 

public use and losses.

Location of retail service areas. Many public-water 

suppliers serve customers outside city limits or in multiple counties or States.

Estimating public water and losses and transfer water 

amounts for public supply is not required; however, the data 

are likely to be collected as part of the survey. This information can be used to estimate water withdrawals. The difference 

between total raw water and metered uses is equivalent to 

public use and losses in USGS Circular 1200, Estimated use of 

water in the United States in 1995 (Solley and others, 1998). 

This publication indicates that public use and losses averaged 15 percent of public-supply withdrawals in the United 

States during 1995 (Solley and others, 1998). Public use and 

losses vary substantially among water suppliers, depending on 

treatment needs, system efficiency, and the amount of publicsupply water use. For example, older systems and those that 

are undergoing repairs to lines or towers have greater losses 

because of leaks, flushing, and tower draining than systems 

with few problems. Often public use and system losses cannot 

be separated. 

Information on water transfers is necessary for estimating public-supply withdrawals. Estimates of total water use for 

suppliers using a combination of their own withdrawals and 

purchased water, or for those selling water wholesale, should 

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 Guidelines for Preparation of State Water-Use Estimates for 2005
be adjusted to identify withdrawals by the county in which 

they occur.

An effort should be made to estimate water withdrawals 

for each public-supply system in the county. At a minimum, 

water-withdrawal data should be obtained for the public suppliers of greater amounts of water in each county. For public 

suppliers of smaller amounts of water, especially those not surveyed, water use may be estimated based on water-right allocations, average water production, previously reported usage, or 

changes in population or population served. Sometimes estimates of total withdrawal for a public-supply system are based 

on estimates of water delivered to residential, commercial, or 

industrial customers or perhaps only on estimates of publicsupply deliveries to residential customers. Depending on the 

size of the public-supply system and on the available time and 

resources, estimates of commercial and industrial deliveries 

and public use and losses should be added to domestic-delivery 

estimates to approximate total public-supply water use. 

Public-supply water withdrawals for the smaller systems 

also may be estimated using population served and a total public-supply per capita use coefficient. Preferably, the coefficient 

is derived from public-supply systems of similar size, similar 

customer base, similar rate structures, similar demographic 

and socioeconomic characteristics, or similar climatic and 

geographic settings. 

Per Capita Use Coefficients

A per capita use coefficient may be used to estimate total 

public-supply water use or domestic deliveries from public 

supply. In each case, the per capita use coefficient usually has 

a different value. Per capita coefficients for both total publicsupply withdrawals and domestic deliveries are commonly 

expressed in terms of gallons per person per day and require 

an estimate of population served. For this report, the per 

capita use term is differentiated for convenience of discussion: 

total public-supply per capita use coefficient and public-supply

domestic per capita use coefficient. A related term is selfsupplied domestic per capita use coefficient, which is described 

in the Self-Supplied Domestic section in this report. Total public-supply per capita use is derived by dividing average daily 

total public-supply water use by the population served only by 

the system. Total water-use accounts for the water withdrawn 

and purchased by a system and subtracts from that amount 

the water sold to other systems. Total public-supply per capita 

use coefficients are generally larger for systems that serve 

industrial and commercial users or have large losses. Publicsupply domestic per capita use is derived by dividing average 

daily domestic deliveries by the population served only by the 

system. Other sources of total public-supply per capita use and 

public-supply domestic per capita use coefficients include the 

documentation from previous compilations, technical literature, or State administrative or legislative documents. 

Population Served 

Population served refers to the population within a county 

receiving water from a public-supply system on a year-round 

basis and excludes vacationers and second-home owners. 

Persons living on military bases, on Native American Indian 

reservations, and in prisons constitute a population served by 

the public-water system serving those communities. Population served by public-water suppliers is estimated for all 

public-water suppliers regardless of the source of the water 

(ground water, surface water, purchased water, or a combination of sources of water). Population served is compiled in the 

county of residence, which is not necessarily the county where 

the withdrawals occur. Population served within a county cannot exceed the total county population. For the 2005 compilation, population served is required at the county level, but not 

required by source of supply—ground water or surface water. 

A reliable county estimate of population served depends 

on collecting information from public-water suppliers that 

serve customers in that particular county. Crosschecking 

among several sources is recommended to get a sense of 

what the population served actually might be for a county. 

Individual public-water systems, State agencies, and SDWIS 

are sources of population-served data. Additionally, county 

estimates of the percent of housing units with public-supply 

capability were published in the 1990 Census of Population 

and Housing, Summary Social, Economic, and Housing Characteristics, 1990 (U.S. Department of Commerce, 1991, and 

http://factfinder.census.gov/ 1990 census, table H023, Source 

of Water Data Set: Summary Tape File 3 (STF 3)—Sample 

data). Although the data are 15 years old and apply to the 

number of housing units rather than the number of occupiedhousing units, the 1990 census data can be an important part 

of the overall analysis of population served in a county and 

perhaps serve as a baseline from which to compare the population-served data received from the other sources.

Population-served numbers may be unreliable for several 

reasons and should be checked. Some potential problems 

include service-area boundaries, which for many public suppliers do not correspond to political boundaries such as city 

limits or county lines; therefore, census population is adjusted 

to accommodate customers living outside city limits or county 

lines to account for total population served. For water suppliers with service areas that span more than one county, an 

estimate is made of the population residing in each county.

In estimating population served, other errors may be 

caused by counting the population served more than once, 

especially if a supplier providing wholesale water supplies 

to other systems reports a population-served number that 

may erroneously include both retail and wholesale population-served numbers. Errors in a reported population served 

sometimes can be detected when comparing aggregated county 

population served to total county census populations. 

Public Supply 
If population-served numbers are not available, population served can be estimated based on the number of residential connections and the number of persons per household. 

This technique is useful for determining population in service 

areas for which no precise population is available, such as 

large water suppliers that serve parts of multiple metropolitan 

areas, rural water districts, or self-supplied housing developments. Individual water suppliers can provide the number 

of residential connections, which may include multifamily 

dwellings. Because the number of billed residential connections often approximates the number of households that are 

occupied in the service area, this statistic, although not always 

available, is preferred to the more general statistic, total 

number of residential connections. The use of total residential 

connections would likely overestimate the population served. 

Census data on housing characteristics for counties and 

the incorporated places within the counties include ratios of 

average persons per household. As with the population served 

numbers from different sources, the reliability of the number 

of persons per household also should be checked. The population served that is reported by public-water suppliers may be 

over-reported, if it is estimated using a ratio of persons per 

household that is too large. 

Vacationers and users of second homes in publicly supplied areas—also referred to as nonresidents—are not included 

in the population-served number because they have been 

counted in the location of their primary residence. The reduced 

domestic deliveries from public supplies from residents 

temporarily leaving their community are generally minimal 

compared to the increased domestic deliveries that result from 

concentrating a nonresident population, for example, in resort 

areas. In a resort or second-home community, the population 

that is actually served is undercounted resulting in a comparatively larger public-supply domestic per capita use coefficient. 

For example, a county population of 13,000 persons, of which 

10,000 are supplied by a public supply, is supplemented by 

a steady influx of 5,000 nonresidents year-round, so that the 

public supply provides water for 15,000 persons. In calculating a public-supply domestic per capita use coefficient, 

domestic deliveries are divided by the 10,000 persons, not 

15,000. To determine if this is a major problem, local public 

supplies, planners, or consulting firms may be able to provide 

an estimate of the percentage of second homes in areas that 

may house a large number of nonresidents.

Domestic Deliveries

Public-supply deliveries for domestic purposes will be 

estimated for 2005. Domestic-delivery data may be collected 

from the appropriate State agency or from the public-supply 

system, estimated using population served and a publicsupply domestic per capita use coefficient, or estimated from a 

sampling of the public-supply systems. Techniques for compiling public-supply data have been described at the beginning 

of this section and apply to public-supply domestic-delivery 

data. Useful information to request from the appropriate State 

agency or public-supply system by mail, fax, or phone surveys 

are included in the earlier sample survey information in the 

Public Supply section in this report. In particular, these two 

items from the earlier list are helpful.

Number of residential service connections 

Amounts of water delivered for domestic purposes 

during 2005

Billing records maintained by a public supply are a 

good source of information for water delivered to domestic 

users—that is, residential water sold. Domestic deliveries 

may be approximated by looking at amounts of water billed 

to single-family and multifamily buildings. Meter sizes are 

another method of distinguishing residential deliveries from 

other deliveries. For example, meter sizes of 5

/8 and 3⁄4 inch are 

common for households, although in many areas larger meters 

are installed for residences because of additional water needed 

for outdoor watering.

Estimating Domestic Deliveries Using 

Population Served and a Coefficient

Domestic deliveries from public supply can be estimated 

using population served and a public-supply domestic per 

capita use coefficient. More than one public-supply domestic 

per capita use coefficient may have to be determined for a 

State. Residential use varies from household to household; 

however, households served by the same public-supply system 

often have a common pattern of use influenced by factors such 

as water rates, water-conservation programs, lot size, customer 

affluence, climate, and topography. As a result, a public-supply domestic per capita use coefficient can be determined for 

a system (described earlier in this section). Although publicsupply systems with similar water-use characteristics are likely 

to have similar per capita use coefficients, among systems, 

a common pattern of residential use, especially outdoor use, 

may not exist because of variation in the above set of factors. 

Therefore, the coefficient for one system may or may not be 

valid for all systems within the State. 

Outdoor water use can be a significant component of 

domestic deliveries, especially in arid climates; this outdoor 

usage is reflected in the per capita use coefficient. In some 

areas, residential communities may receive potable water from 

a public-water supplier for indoor use and nonpotable water 

through a separate distribution system for outdoor irrigation 

of lawns and gardens. An example of a “dual-use” area is 

where developers provide the nonpotable water to houses in 

urban areas built on former farmland, using water previously 

allocated for agricultural irrigation use. Public-supply domestic per capita use coefficients in these dual-use areas generally 

are lower than in areas where customers use publicly supplied 

water for indoor and outdoor uses.

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10 Guidelines for Preparation of State Water-Use Estimates for 2005
Estimating Domestic Deliveries as a Percent of 

Total Public-Supply Water Use

In previous compilations, domestic deliveries had been 

estimated for some States as a percentage of the total water 

use for a system, a county, or a State. Because the customer 

base of public suppliers may vary a great deal, caution should 

be used in applying county- or State-wide percentages. Some 

of the percentages applied to total public-supply use for 

domestic deliveries date back several compilations. Just as 

the trends in water-use withdrawals have changed, especially 

since 1980, it is likely that the proportion of the deliveries 

from the public supply to domestic and other customers has 

changed, especially for commercial and industrial deliveries. In determining the percentage of domestic deliveries 

compared to total deliveries, an exploratory sampling of a 

selected sets of public-supply delivery data should be taken to 

test if applying a percent to total deliveries would be a valid 

approach and then to determine what a representative percentage would be for either a county, a region, or the State. 

Self-Supplied Domestic

Domestic water use is water used for both indoor and 

outdoor household purposes. Common indoor uses include water 

for drinking, food preparation, bathing, washing clothes and 

dishes, and flushing toilets. Major outdoor uses include watering lawns and gardens and washing cars. Water for domestic 

use may be delivered from a public supplier, withdrawn from a 

private source such as a well or spring, or captured as rainwater 

in a cistern. 

Data Elements

The category of self-supplied domestic consists of the 

following mandatory and optional data elements. Data for the 

optional elements may be compiled and entered into AWUDS, 

but will not be part of the national water-use analysis for 2005 

as published in the water-use circular series. The optional data, 

however, will be available for other types of water studies. 

Mandatory

Ground-water withdrawals, freshwater, by county

Surface-water withdrawals, freshwater, by county

Optional

Consumptive use, freshwater, by county

Any data aggregated by eight-digit hydrologic 

cataloging unit

Ground-water withdrawals, by principal aquifer

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Sources of Information

For each USGS Water Science Center, the documentation for the previous compilations should be the starting point 

for planning the data collection for the 2005 compilation. 

The previous documentation for the self-supplied domestic 

category may contain the location and types of electronic and 

paper files; agency and contact information; agency and Internet resources; and methods, techniques, and coefficients used 

to collect or estimate data. Other sources of information may 

be available in each State. Additional information concerning 

self-supplied domestic water use may be obtained from the 

following sources.

Agencies or Other Entities

Possible contacts for self-supplied domestic water-use 

data are listed as follows. Water-use data from these sources 

can range from reported water withdrawals to coefficients and 

ancillary data that can be used to estimate water withdrawals 

and domestic self-supplied population. Multiple data sets can 

be used to determine the best estimates and provide QA/QC. 

Governmental agency responsible for well permits for 

individual households 

Public-water supply records of residential use

Public-water supply records of population served

State pollution-control agencies

State agency responsible for water permitting

Ground-water resource studies

Local chambers of commerce

State public health agencies

Wastewater-treatment facility billing 

Local wastewater lagoon designs

Tax appraiser’s office

State and regional planning agencies

Technical literature

State administrative or legislative documents

State projections of water demand

American Water Works Association research 

Consulting firms

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Self-Supplied Domestic 11
Internet Resources

Many agencies and other entities maintain self-supplied 

domestic water-use information and databases on the Internet. 

Specific Internet addresses are listed as they appeared on the 

date last accessed. 

U.S. Census Bureau, accessed June 6, 2006, at 

<http://www.census.gov/>

American FactFinder, the U.S. Census Bureau’s 

online data source, accessed June 6, 2006, at 

<http://factfinder.census.gov/>

Summary File 1, in “Data Sets,” includes selected 

population and housing characteristics to the block/

census tract level.

USEPA, accessed June 6, 2006, at <http://www.epa.gov/>

Water Discharge Permits, PCS database, accessed 

June 6, 2006, at <http://www.epa.gov/enviro/html/

pcs/pcs_query_java.html>

Access to data regarding facilities holding NPDES 

permits. Specify the facilities by using any combination of facility name, geographic location, SIC code, 

and chemicals.

American Water Works Association, accessed June 6, 

2006, at <http://www.awwa.org/>

WaterWiser, the Water Efficiency Clearinghouse, 

accessed June 6, 2006, at <http://www.awwa.org/

waterwiser/>

Compilation Techniques

The approach to estimating self-supplied domestic water 

withdrawals depends on the type of data available to the study 

chief. Self-supplied domestic water withdrawals typically are 

estimated by multiplying the self-supplied population by a 

self-supplied domestic per capita use coefficient. Selfsupplied population is calculated by subtracting total population served by a public supply in a county from the total census population in the county. The reliability of the estimate 

of self-supplied population depends on the reliability of the 

population-served numbers. Self-supplied domestic water 

withdrawal estimates may be more accurate if the self-supplied domestic per capita use coefficient is determined for 

separate geographic areas of the State that have distinctive 

climatic or water-use characteristics. A public-supply domestic per capita use coefficient may be substituted for a selfsupplied domestic per capita use coefficient if the publicly 

supplied and self-supplied populations are believed to be 

similar in terms of water use. A suggested method for developing public-supply domestic per capita use coefficients is to 

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obtain data on public-supply water withdrawals or domestic 

deliveries—depending on available data—and population 

served from a cross section of several small water suppliers 

that likely serve only residential customers. Public-supply 

water withdrawals—or domestic deliveries—divided by the 

population served will result in an estimate of public-supply domestic per capita use. The public-supply domestic per 

capita use is likely to be similar to a self-supplied domestic 

per capita use, unless extraordinary conditions influence the 

patterns of use within the system or within in the self-supplied area. If public-supply domestic per capita use rates are 

similar throughout the State, an average public-supply domestic per capita use for the entire State may be appropriate. If 

public-supply domestic per capita use rates developed from 

the sampling indicate regional differences within the State, 

an average public-supply domestic per capita use should be 

estimated for each county or region. 

Self-supplied or publicly supplied domestic per capita use 

coefficients also may be obtained from estimates provided by 

other agencies or from technical, administrative, or legislative 

literature. Some States have published projections of future 

water demands and may have calculated per capita use rates. 

Regional and State planning agencies, State natural-resource 

agencies, or the State’s public health agency are possible 

sources for this information. Per capita use coefficients also 

have been determined as part of research conducted by professional organizations, such as the American Water Works 

Association, and by consulting firms. 

Self-supplied domestic withdrawals sometimes can 

be estimated using information from wastewater-treatment 

facilities that set fees according to metered water use. In areas 

where sewer districts serve houses that are not on public water 

supplies, wastewater-treatment facilities often maintain information about self-supplied residences for billing purposes. 

This information can be used to estimate withdrawals for areas 

and to develop per capita use coefficients along with population and housing data. State pollution-control agencies also 

estimate per capita uses when designing wastewater lagoons. 

These design values, usually from about 80 to 100 gallons per 

capita per day (gpcd), may provide a good estimate of domestic per capita use. Other coefficients, such as gallons per day 

per household or gallons per day per household market value, 

are available from the literature and can be used to determine 

domestic self-supplied withdrawals in areas for which ancillary data on housing are available.

Domestic self-supplied withdrawals typically are from 

wells. The source for about 98 percent of self-supplied 

domestic withdrawals during 2000 was ground water (Hutson 

and others, 2004). Information on the use of surface water for 

domestic supply may be obtained from the State public health 

agency, the State agency responsible for permitting or wateruse data collection, census housing data, or local knowledge 

of areas where surface water is used. Cisterns used to collect 

rainwater for domestic use generally are considered as surfacewater sources. Springs are considered surface water in some 

States and ground water in others. 

12 Guidelines for Preparation of State Water-Use Estimates for 2005
Industrial

Industrial water use includes water used for such purposes as fabricating, processing, washing, diluting, cooling, 

or transporting a product; incorporating water into a product; 

or for sanitation, maintenance, or landscaping needs of the 

facility. Industrial water users are businesses classified in the 

SIC codes under construction and manufacturing. Industrial 

water supplies may be derived from ground water, surface 

water (self-supplied industrial withdrawals) or reclaimed 

wastewater or provided by a public-water supplier (publicsupply industrial deliveries). For 2005, reclaimed wastewater 

use is a mandatory data element for the industrial category. 

Zeros should be reported for counties where the delivery of 

reclaimed wastewater does not occur, but null values can be 

stored in AWUDS for counties where the use of reclaimed 

wastewater is uncertain. 

Data Elements

The category of industrial consists of the following mandatory, mandatory but null values allowed, and optional data 

elements. Data for the optional elements may be compiled 

and entered into AWUDS, but will not be part of the national 

water-use analysis for 2005 as published in the water-use circular series. The optional data, however, will be available for 

other types of water studies. 

Mandatory

Ground-water withdrawals, freshwater, by county

Ground-water withdrawals, saline water, by county

Surface-water withdrawals, freshwater, by county

Surface-water withdrawals, saline water, by county

Mandatory but Null Values Allowed

Reclaimed wastewater, by county

Optional

Deliveries from public supply, by county

Consumptive use, freshwater, by county

Consumptive use, saline water, by county

Number of facilities, by county

Any data aggregated by hydrologic cataloging unit

Ground-water withdrawals aggregated by 

principal aquifer

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Sources of Information

For each USGS Water Science Center, the documentation for 

the previous compilations should be the starting point for planning the data collection for the 2005 compilation. The previous 

documentation for industrial water-use category may contain 

the location and types of electronic and paper files; agency and 

contact information; agency and Internet resources; and methods, techniques, and coefficients used to collect or estimate data. 

Additional information on industrial facilities and the associated 

water use may be obtained from the following sources. Other 

sources of information may be available in each State.

Agencies or Other Entities

Possible contacts for industrial water-use data are listed 

as follows. Water-use data from these sources can range from 

reported water withdrawals to coefficients and ancillary data that 

can be used to estimate water withdrawals. Multiple data sets can 

be used to determine the best estimates and provide QA/QC. 

State agencies that administer water rights, allocate 

water to users, or collect water-use data

State agencies that issue permits for the discharge 

of water

Health departments or public-water suppliers—many 

industries receive treated water for sanitary uses

Wastewater-treatment facilities

State department of labor

State and county planning departments

State directories of manufacturers

Local chambers of commerce

County assessors and zoning boards

Internet Resources

Many agencies and other entities maintain industrial wateruse information and databases on the Internet. Specific Internet 

addresses are listed as they appeared on the date last accessed. 

U.S. Census Bureau, accessed June 6, 2006, at 

<http://www.census.gov/>

2002 Economic Census and Surveys, accessed June 6, 

2006, at <http://www.census.gov/econ/census02/>

County-level data; number of establishments/

employees by manufacturing industry; accessed 

through the American FactFinder, U.S. Census 

Bureau’s online data source, accessed June 6, 

2006, at <http://factfinder.census.gov/servlet/

DatasetMainPageServlet?_program=ECN&_

lang=en&_ts=/ >

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Industrial 13
Sector-specific reports by State, accessed June 6, 

2006, at <http://www.census.gov/econ/census02/

guide/geosumm.htm>

Industry series reports—Manufacturing, accessed 

June 6, 2006, at <http://www.census.gov/econ/

census02/guide/INDRPT31.HTM>

USEPA, accessed June 6, 2006, at <http://www.epa.gov/>

Water Discharge Permits, PCS database, accessed 

June 6, 2006, at <http://www.epa.gov/enviro/html/

pcs/pcs_query_java.html>

Access to data regarding facilities holding NPDES 

permits. Specify the facilities by using any combination of facility name, geographic location, SIC code, 

and chemicals.

Dun and Bradstreet, accessed June 6, 2006, at 

<http://www.dnb.com/us/index.asp>

Source for lists of manufacturing establishments that 

includes SIC codes and number of employees, among 

other information.

Harris InfoSource, accessed June 6, 2006, at 

<http://www.harrisinfo.com/>

Source for purchasing lists of manufacturing establishments. Profile reports include primary and secondary 

SIC codes, number of employees, Internet address of 

company, if available.

Compilation Techniques

Self-supplied industrial withdrawals tend to occur within 

particular industry groups that require large amounts of water 

for fabricating, processing, washing, diluting, cooling, or 

transporting a product or incorporating water into a product. 

There are exceptions in which the more water-use-intensive 

industries are publicly supplied and the less water-use-intensive industries are self-supplied. Major industrial groups that 

historically have been self-supplied include food and kindred 

products (SIC 2011–2099), paper and allied products (SIC 

2611–2679), chemicals and allied products (SIC 2812–

2899), petroleum-refining and petroleum-related industries 

(SIC 2911–2999), and primary metals industries (SIC 3312–

3399). Although these types of industries historically have 

used the most water per facility, the most important industry 

in any given county may not fall into one of these five groups. 

Therefore, it is important to consider any industries outside 

these groups.

Constructing a master list of industrial facilities is fundamental to all of the compilation techniques. A master list, at a 

minimum, consists of the names and locations of industries, 

and sources of water. The information to build or update this 

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list may be available from previous documentation, one or 

more State agencies, or from USGS water-use databases. State 

reporting programs and individual industries are good sources 

of data. Reporting agencies have varying criteria for obtaining 

industrial water-use data; these criteria determine if withdrawals are permitted, registered, or monitored; the trigger levels 

for reporting and the application of the trigger level to groundwater or surface-water sources; and whether the reporting is 

Statewide or applies to selected counties or watersheds. If the 

reporting criterion is a minimum water withdrawal rate and 

that withdrawal rate is large, a significant number of small 

industries may not be surveyed. For this reason, some needed 

industrial facility information may not have been collected by 

the State agency and, therefore, must be obtained directly from 

the industry or be determined from other ancillary information. 

Water Withdrawals

There are three general approaches used to compile withdrawal data by industries:

Acquire site information and withdrawal data for 

individual industries, focusing on larger ones while 

striving for an adequate representation of the withdrawals in each county.

Acquire site information with ancillary data on 

employment or production, and estimate water withdrawals using water-use coefficients. These coefficients are usually in the form of usage in gallons per 

day per employee or per unit of product.

Combine the two approaches by acquiring industrial 

facility information and water withdrawals for the 

larger industries and using these data to develop 

water-use coefficients for estimating withdrawals for 

the smaller industries. 

Industrial water information may be acquired through 

telephone contacts, site visits, or surveys sent out by cooperating agencies. The level of detail obtained depends on the availability of the information and the necessary resources available to collect the data. Confidentiality should be considered. 

Useful data to acquire include:

Facility name, mailing address, physical plant 

facility address

County

Contact name, title, telephone and fax number, 

and e-mail 

Industry description or principal products

SIC codes—primary and secondary

Estimated annual quantity of product produced

Total number of employees

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14  Guidelines for Preparation of State Water-Use Estimates for 2005
Number of ground-water sources, aquifer names, 

number and depth of well(s)

Number of surface-water sources, names of streams 

or water bodies

Latitude and longitude of wells or intakes

Maps of facility and water intakes

Name of public water-supply sources

Amounts of water withdrawn and time period of 

withdrawal for each source

Amount or percentage of total withdrawal that is freshwater or saline water, ground water or surface water

Method of determining withdrawals (meters, other)

Percentage of total or amount of water used for 

cooling, processing, sanitary use, boiler feed, power 

generation, other

Amount of water recycled or reused

Wastewater discharge—average amount or percentage

Number of days operating each year

Average number of hours operating each day

Approximate age of the facility

Confidentiality statement

Water-Use Coefficients

In the absence of reported data, industrial water withdrawals can be estimated using water-use coefficients and 

ancillary data such as numbers of employees, units of production, or annual sales. The largest industries should be contacted to acquire actual water-use withdrawal data. These withdrawals then can be used to develop locally adjusted water-use 

coefficients to estimate withdrawals for smaller industries.

The use of coefficients to estimate industrial water use is 

imprecise because of the variability in factors affecting water 

use by industries. The specific processes, age of the facility, 

cost of the water and wastewater treatment, and amount of 

recycling all contribute to the amounts of water needed by 

an industry. These factors should be considered when using 

national coefficients or when developing and adjusting local 

coefficients for industries not surveyed. 

Allocation of Water Withdrawals by Source

Allocating industrial water withdrawals by source and 

quality of water is often best done by combining local knowledge of water sources for neighboring industrial or publicsupply facilities and applying spatial analysis. Plotting pos-

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sible areas or locations of industrial activity on watershed 

and principal aquifer coverage maps can help determine the 

probable sources of water. Many industries are located in 

specific areas of ample supply of water from rivers or productive aquifers. Determining freshness or salinity of water also 

may require some knowledge of the type of industrial activity. 

Spatial analysis may indicate the possibility of tapping into a 

saline water source; however, the industrial process for which 

the water is needed may require freshwater. Seawater and 

estuary-bay water are the primary sources of saline surface 

water in the United States. Generally, because the use of saline 

ground water for industrial use is so specific and unique, the 

saline ground water is known within the State rather than surmised. The USGS ground-water specialist in each State may 

be able to help identify areas noted for having saline ground 

water that would strengthen the spatial analysis. For industry, 

saline water is water that contains 1,000 mg/L or more of dissolved solids. 

Irrigation

Water for irrigation is applied by an irrigation system to 

sustain growth in agricultural and horticultural vegetation and 

also is applied for the purposes of pre-irrigation, frost protection, weed control, field preparation, crop cooling, harvesting, 

dust suppression, leaching of salts from the root zone, and the 

application of chemicals (SIC 0111–0191 and 4971). Irrigation withdrawals include conveyance losses. Irrigation of golf 

courses (SIC 7992 and 7997), parks, nurseries, turf farms, 

cemeteries, and other self-supplied landscape-watering uses 

also are included in the irrigation category. Water may be 

withdrawn by the irrigator or delivered from irrigation companies, irrigation districts, irrigation cooperatives, or governmental entities, but not purchased from a public supply. Instead, 

public-supply deliveries for irrigation users, golf courses, 

parks, cemeteries, and landscaping irrigation are either commercial deliveries or public-use water. The number of irrigated 

acres by type of irrigation system—sprinkler, surface (flood), 

and microirrigation are in the irrigation category. Reclaimed 

wastewater use is a mandatory data element for the irrigation 

category. Zeros are reported for counties where the delivery 

of reclaimed wastewater does not occur, but null values can 

be stored in AWUDS for counties where the use of reclaimed 

wastewater is uncertain. 

For the 2005 compilation, States may divide total irrigation water use into crop irrigation and golf course irrigation. In this case, only golf course irrigation withdrawals are 

included in golf course irrigation; all other landscape irrigation 

is included with crop withdrawals. If irrigation is divided in 

this manner, county-level totals for both crop and golf course 

irrigation are mandatory where applicable, and total irrigation 

water withdrawals are calculated as the sum of the two subcategories. If irrigation withdrawals are not divided into crop and 

golf course withdrawals, then all irrigation is reported as total 

withdrawals and may include both types.

Irrigation 15
Data Elements

The category of irrigation consists of the following mandatory, mandatory but null values allowed, and optional data 

elements. Data for the optional elements may be compiled 

and entered into AWUDS, but will not be part of the national 

water-use analysis for 2005 as published in the water-use circular series. The optional data, however, will be available for 

other types of water studies. 

Mandatory

Ground-water total withdrawals, freshwater, by county

Surface-water total withdrawals, freshwater, by county

Acres irrigated by sprinkler systems, by county

Acres irrigated by surface systems, by county

Acres irrigated by microirrigation systems, by county

Mandatory but Null Values Allowed

Reclaimed wastewater, by county

Optional

Divided crop and golf course ground-water withdrawals, freshwater, by county

Divided crop and golf course surface-water withdrawals, freshwater, by county

Consumptive use, by county

Conveyance loss, by county

Any data aggregated by hydrologic cataloging unit

Total ground-water withdrawals, by principal aquifer

Sources of Information

For each USGS Water Science Center, the documentation 

for the previous compilations should be the starting point for 

planning the data collection for the 2005 compilation. The previous documentation for the irrigation category may contain 

the location and types of electronic and paper files; agency and 

contact information; agency and Internet resources; and methods, techniques, and coefficients used to collect or estimate 

data. Additional information concerning irrigation water use 

may be obtained from the following sources. Other sources of 

information may be available in each State.

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Agencies or Other Entities

Possible contacts for irrigation water-use data are 

listed as follows. Water-use data from these sources can range 

from reported water withdrawals to coefficients and ancillary 

data that can be used to estimate water withdrawals and determine irrigated acreage by irrigation system type. Multiple

 data sets can be used to determine the best estimates and 

provide QA/QC. 

State agencies that administer water rights, allocate 

water to users, or collect water-use data

U.S. Department of Agriculture (USDA), Agricultural 

Statistics Service for a specific State

USDA, NASS

USDA, Natural Resources and Conservation Service 

(NRCS), State or county offices

USGS research or studies

Watermasters

Equipment manufacturers

Federal or State crop and livestock reporting services

State and local turf-grower associations

County assessor

Land-grant universities—college of agriculture, departments of watershed science, soil science, plant science, 

crop science, or irrigation engineering

Water management districts, irrigation districts, 

irrigation companies

Irrigation equipment dealers

Farm and crop improvement associations

Golf courses, parks, and other recreational areas

Professional, technical, and trade journals

State departments of commerce and tourism

Internet Resources

Many agencies and other entities maintain irrigation wateruse information and databases on the Internet. Specific Internet 

addresses are listed as they appeared on the date last accessed. 

USDA, accessed June 6, 2006, at <http://www.usda.gov/>

2003 Natural Resource Inventory, accessed June 6, 

2006, at <http://www.nrcs.usda.gov/technical/NRI/>

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16  Guidelines for Preparation of State Water-Use Estimates for 2005
NRCS Irrigation Page, accessed June 6, 2006, at 

<http://www.wcc.nrcs.usda.gov/nrcsirrig/>

Farm Service Agency, accessed June 6, 2006, at 

<http://www.fsa.usda.gov/>

Cooperative State Research, Education, and Extension Service (CSREES), accessed June 6, 2006, at 

<http://www.csrees.usda.gov/>

State partners of the CSREES (includes agricultural 

experiment stations and county cooperative extension offices), accessed June 6, 2006, at <http://www.

csrees.usda.gov/qlinks/partners/state_partners.html>

Local partners, accessed June 6, 2006, at 

<http://www.csrees.usda.gov/Extension/index.html>

NASS, accessed June 6, 2006, at 

<http://www.usda.gov/nass/>

Links to NASS Web sites for each State, accessed 

June 6, 2006, at <http://www.nass.usda.gov/

Statistics_by_State/index.asp>

State Web sites may include links to information such as agricultural statistics, publications 

(including annual bulletins), and general information on agriculture in that State; other State agricultural agencies; and agricultural census data.

Quick Stats: Agricultural Statistics Database—

custom queries for agricultural statistics, down to 

the county level, accessed June 6, 2006, at 

<http://www.nass.usda.gov/QuickStats/>

2002 Census of Agriculture, accessed June 6, 2006, 

at <http://www.nass.usda.gov/Census_of_

Agriculture/index.asp>

Farm & Ranch Irrigation Survey, accessed June 

6, 2006, at <http://www.nass.usda.gov/census/

census02/fris/fris03.htm>

State-level data on acres irrigated by irrigation 

method; application rates by irrigation method, 

source of water, and crop type.

1998 Census of Horticultural Specialties, accessed 

June 6, 2006, at <http://www.nass.usda.gov/

census/census97/horticulture/horticulture.htm>

State-level data on acres for horticultural crops, 

including acres irrigated by source of water and 

acres irrigated by type of irrigation system.

U.S. Department of the Interior, Bureau of Reclamation, accessed June 6, 2006, at <http://www.usbr.gov/>

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Annual operating plans for federally owned 

dams and reservoirs operated by irrigation or 

reclamation districts, accessed June 6, 2006, at 

<http://www.usbr.gov/gp/water/index.cfm>

AgriMet is a network of automated agricultural 

weather stations located in irrigated agricultural 

areas throughout the Pacific Northwest and Montana:

Pacific Northwest Region, accessed June 6, 2006, 

at <http://www.usbr.gov/pn/agrimet/>

Great Plains Region (Montana), accessed June 6, 

2006, at <http://www.usbr.gov/gp/agrimet/index.cfm>

USEPA, accessed June 6, 2006, at <http://www.epa.gov/>

Water Discharge Permits, PCS database, accessed 

June 6, 2006, at <http://www.epa.gov/enviro/html/

pcs/pcs_query_java.html>

Access to data regarding facilities holding NPDES 

permits. Specify the facilities by using any combination of facility name, geographic location, SIC code, 

and chemicals.

Food and Agriculture Organization (FAO) of the United 

Nations, accessed June 6, 2006, at <http://www.fao.org>

Crop evapotranspiration – Guidelines for computing 

crop water requirements—FAO Irrigation and 

Drainage Paper 56, accessed June 6, 2006, at 

<http://www.fao.org/docrep/X0490E/X0490E00.htm>

GolfServ.com, accessed June 6, 2006, at <http://www.

golfserv.com/apps/courses/search.asp>

Users can search the database for a listing of golf courses 

in each State—includes data on public and private courses, 

number of holes, location, and links to each course’s 

profile and Web site (if they have one). Registration on the 

Web site (free) is required to access specific course data.

Golfonline.com, accessed June 6, 2006, at 

<http://www.golfonline.com/golfonline/coursefinder >

Users can search the database for a listing of golf 

courses in each State—includes information on number 

of holes. No registration is required. 

Compilation Techniques 

Irrigation water withdrawals and reclaimed wastewater 

use are compiled according to the county in which the withdrawals or diversions occur. The number of acres irrigated is 

counted where the irrigation water is applied. In most cases, 

irrigation water is applied close to where it is withdrawn or 

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Irrigation 17
diverted; in some cases, the irrigation water is transported long 

distances through canals. Problems in estimating irrigation 

water use include:

Unknown number of irrigated acres

Possibility of single or multiple cropping patterns

Possibility of multiple sources of water: surface water, 

ground water, or reclaimed wastewater

The effect of age and design on application rates for 

irrigation systems

Unexpected seasonal irrigation needs such as frost 

protection or harvesting

Gap in permitted amounts compared to use amounts

Censoring of data for privacy reasons

Spatial scale (watershed, irrigation district, etc.) of 

primary-source data compared to the needed countyscale data for the compilation

Direct methods for compiling information on irrigation 

withdrawals and irrigated acres include use of reported data, 

surveys, and personal contact. Indirect approaches for estimating withdrawals include calculation of crop water needs and 

statistical sampling. Data on irrigated acres by crop type and 

golf course, coupled with irrigation system type are used in 

most estimation methods for determining withdrawals. 

Total withdrawals need to be disaggregated to ground-water 

and surface-water sources if information on site-specific withdrawals is not available. 

Reported Data

Some States require individual water users or water right 

holders to measure and report their withdrawals and irrigated 

acreages for each well or surface-water diversion. These data 

are considered the best because the location of the withdrawals 

can be accurately assigned and aggregated to a county, aquifer, 

or other area. Other sources of reported data may yield partial 

coverage of irrigation use. USGS cooperative studies may 

include measurement of site-specific data in local areas within 

a State. Irrigation districts or other agencies may own water 

rights and distribute water to users; these entities usually measure both withdrawals and deliveries. Watermasters may have 

been assigned to measure or compile measured withdrawals 

and deliveries in some areas, in which case they are excellent 

sources of data.

Reported measurements are the most defensible data; 

however, the completeness of reported data varies among States. 

Before using data that are reported to or by other Federal, State, 

and local agencies, it is important to understand the level of 

completeness, the degree of accuracy, and the amount of QA/

QC given to data. USGS water-use study chiefs need to verify 

whether the data are based on full and complete enumerations, 

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like a census, or are statistically based, like the NASS data. 

Reported crop acreages may include all crop acreages or just 

irrigated acreages. Irrigated acreages and water deliveries may 

be reported for an area of management of a particular agency, 

or for an entire county. Some data may be censored for privacy 

reasons in areas with few irrigators. Reported withdrawals and 

acreage data need to be reviewed for errors, either by the reporting agency or by the USGS water-use study chief. Knowing the 

level of QA/QC for data that are reported by other agencies may 

prevent calculations that are based on incorrect assumptions.

Surveys and Personal Contact

Another method of estimating irrigation water use is by 

a local survey. Surveys that are conducted by USGS rather 

than a cooperator need to comply with the requirements of 

the 1995 Paper Reduction Act. Ideally, survey forms include 

a complete background about why the information is being 

requested, how it will be used, and by whom. Other important 

components of the survey are (1) a concise description of the 

requested data, (2) a contact name and phone number to direct 

questions to, and (3) a desired completion date. In any case, 

efficient collection and processing of survey data can be best 

achieved if the survey forms are short and easy for the user to 

complete. Typically, other State and local agencies distribute 

surveys, and the data are shared with the USGS.

It is important to get accurate data on water users who 

use the greater amounts of water; these users typically have 

more data available than water users who use lesser amounts 

of water. When developing survey lists, data sources such as 

the USDA’s Census of Agriculture can be used to target counties with the water users who use the greater amount of water. 

Some of the most beneficial survey information includes:

Total irrigated acreage 

Crop and pasture acreage 

Type and efficiency of irrigation system(s)

Quantity or flow rate of water by source 

Irrigation scheduling and frequency 

Number of irrigation wells 

Total depth of well(s)

Capacity of well(s)

Contributing aquifer system(s) 

Total annual energy usage 

Power consumption coefficient(s) if known

Other useful data include information on crop water shortages, acres harvested and yields by crop, energy sources, water 

and agricultural management practices, and any agricultural 

resources that generally are contacted when the irrigator needs 

additional guidance.

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18  Guidelines for Preparation of State Water-Use Estimates for 2005
Estimates of Crop Water Needs

A commonly used method to estimate irrigation withdrawals involves calculating consumptive use for irrigated crops 

using crop water-consumption coefficients for several crops 

and system types (see Allen and others, 1998; U.S. Department 

of Agriculture, 1970, 1976, 1997, 2002). The amount of water 

consumed by crops, plus additional water used in conveyance 

or needed for other irrigation uses, is the total withdrawal. This 

method requires that ancillary data exist for total irrigated acres 

for each type of crop, irrigation system efficiencies, conveyance losses, climatic variables, and other irrigation management practices—such as pre-irrigation, frost protection, weed 

control, and leaching salts from soils. This consumptive-use 

technique assumes that the irrigation water applied is adequate 

for optimal plant growth and that the plants are not being irrigated with more or less water than needed.

Application efficiency is a measure of the effectiveness of 

the irrigation system in applying the right amount of water to 

the soil and root zones over time. Application efficiency must 

be taken into account if irrigation withdrawals are estimated 

from crop water-consumption coefficients. Application efficiencies vary with the type of irrigation system and soil, crop, 

topographic, and climatic conditions. Pertinent climatic conditions that have large effects on irrigation efficiencies include 

wind speed, relative humidity, and air temperature. 

In many cases, compilation of State withdrawals based 

on crop consumptive use, plus additional climatic and soil factors, is not feasible because of the amount of work and level 

of detailed data necessary. Use of previously determined crop 

consumption values may be the most cost-effective method 

of estimating irrigation withdrawals. These values may be 

obtained from sources such as the USDA irrigation guide 

(U.S. Department of Agriculture, 1970).

Statistical Sampling

For large irrigated areas where few measurements exist, 

statistical sampling represents a cost-effective way to estimate irrigation withdrawals. For this method, withdrawals are 

measured at sample sites where data also are available for such 

variables as power consumption, lift, or crop type. Water-use 

coefficients are developed from these sample data and then 

are used to estimate withdrawals at unsampled sites where the 

predictor variable(s) is known. 

Statistical approaches may have transfer value to other 

areas if there is good understanding of the predictor variables, 

the statistical significance of the predictor variables, and the 

level of expected accuracy. For example, by understanding the 

variability of the predictor variable, a specific number of sample sites may be determined that will enable calculations of 

withdrawals for all sites with a probability that the calculated 

values are within a specific margin of error. Luckey (1972) and 

Helsel and Hirsch (1995) provide a complete description of 

how to determine a sufficient sample size. 

Allocation of Withdrawals by Source

If site-specific measurements of withdrawals are 

unavailable, then the estimates of total withdrawals need to 

be allocated between ground-water and surface-water sources. 

Geographic location is the greatest determinate of water 

availability from each source. Often, there is a predominating 

source of supply for a given State or geographic area. 

The best sources of information about water for irrigation are 

State personnel and county extension agents who work with 

the political and managerial aspects of water resources. 

Irrigation districts and equipment dealers are other good 

sources of local information. 

Acres Irrigated by System Type

Estimates of irrigated acres by system type are compiled 

for each State at the county level. Irrigated acreage is reported 

by three general methods of application—sprinkler, surface, 

and microirrigation. Many types of irrigation systems are 

included in each of these categories.

Sprinkler methods include all boom, center-pivot, lateralmove, low-energy precision application (LEPA), permanent, portable, side-move, side-roll, solid-set, travelinggun, towed, and other sprinkler irrigation systems

Surface methods include all borders, ditch, flood, furrow, gated-pipe, surge-flow, water-spreading, and other 

gravity systems

Microirrigation methods include all bubbler, drip, 

micro-jet, mist, porous trickle-tubing, spray, trickle, 

and other low-volume irrigation systems, and subsurface systems

Reliable data on irrigated acreage also are essential for 

most methods of estimating irrigation water withdrawals. Sitespecific irrigated acres by irrigation system type generally are 

difficult to obtain, except if State agencies require irrigators to 

report detailed information that includes irrigation methods. 

The USDA census of agriculture, conducted in years ending in 

“2” and “7,” provides the most recent national data set of irrigated crop acreages by county (U.S. Department of Agriculture, 2002). The USDA farm and ranch irrigation survey, last 

released during 2003, provides a national data set of irrigated 

acreage by irrigation method by State. County assessors also 

are possible sources for county-level information on irrigated 

acreage and irrigation system type. Remote sensing has been 

used as an indirect method of determining acres irrigated and 

crop types (Raymond and others, 1992), but is not a common 

tool used in this study. 

In some parts of the United States, the growing season 

is long enough that double and triple cropping can occur on 

the same irrigated acreage. In these cases, irrigated acres are 

counted each time the acre is irrigated to reflect the total acreage irrigated during the year; therefore, when any acre of land 

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Irrigation 19
is cropped twice, it is counted as 2 irrigated acres. Counting 

acreage in this manner produces an application rate that is 

comparable to a single-cropping season. The irrigation method 

used on subsequent crops may be different. If multiple irrigation methods are used on a crop in a single growing season, 

acreages are reported under the method that provides most of 

the water to the crop. 

Golf Course Irrigation

Golf courses may use water from ground or surface 

sources, purchased water (from a public supplier or irrigation 

district), reclaimed water from a public wastewater-treatment 

facility, or a combination of these sources. For golf courses, 

the best information on source of water is obtained directly 

from the golf course maintenance personnel. These people 

usually know how much water is diverted, withdrawn, or 

delivered from each of the possible sources. 

Factors affecting the amount of irrigation water used 

at golf courses include course design, climatic conditions, 

acreage, irrigation systems, soils, availability of water for 

irrigation, and local irrigation practices. Normally, more water 

per unit of area is applied to the greens and tees than to the 

fairways. It is best to obtain metered withdrawals for specific 

golf courses. If site-specific data are not available, irrigation 

withdrawals may be estimated using coefficients developed 

from surveys of golf courses in a State. A survey should 

include all of the information necessary to compute an application rate based on the consumptive needs of the grasses and 

the irrigated acres.

Thermoelectric Power

Thermoelectric-power water use is the amount of water 

used in the process of generating thermoelectric power. All 

thermoelectric power plants are classified as SIC 4911. The 

source of the power may be fossil fuels, nuclear fission, or 

geothermal energy. Thermoelectric power plants typically 

generate electricity with a boiler, where water is heated to turn 

it into steam. The steam then is used to turn turbines, which 

generate electricity. After the steam is used to turn the turbines, the steam is condensed to water by cooling it in a heat 

exchanger. The condensed water then is routed back to the 

boiler, where the cycle begins again. The predominant use of 

water is to cool the steam. Boiler water must be freshwater; 

however, cooling water may be fresh or saline.

Water withdrawal requirements at thermoelectric-powergeneration facilities primarily depend on whether or not the 

cooling water is recirculated. The two general types of cooling 

are once-through (open-loop) cooling and closed-loop (recirculation) cooling. For the 2005 compilation, water withdrawal 

and net thermoelectric-power-generation estimates will be 

compiled for each type of cooling system. Once-through cooling requires the largest amounts of water withdrawal because 

the water is not recirculated within the facility. The water is 

withdrawn from a source, circulated through the heat exchangers, and then returned to a water body at a higher temperature. 

This technology is common in older facilities but generally is 

not used for new facilities because of increasingly restrictive 

thermal and other water-quality requirements for return water. 

Closed-loop cooling systems use cooling ponds and cooling towers to recirculate water within the system, thus reducing the overall water withdrawal requirement. Withdrawals 

to replace cooling water lost to evaporation, blowdown, drift, 

and leakage are considered “makeup” water. A cooling pond 

is a shallow reservoir with a large surface area to remove heat 

from circulation water. The rate of heat loss may be enhanced 

by using spray nozzles. A cooling tower is a structure designed 

to remove heat from water. The heated circulation water is 

sprayed into the tower and is cooled by radiation from the 

sides of the tower or contact with the cooler air. Cooling towers commonly are used where land and water are expensive, or 

where local regulations prohibit the release of thermal water. 

For 2005, net power generated is a mandatory data 

element and the value will be stored in AWUDS in units of 

gigawatt-hours (GWhs). A GWh is equivalent to 1 thousand 

megawatt-hours or 1 billion watt-hours. 

Some industrial facilities also generate thermoelectric 

power. These facilities are combined heat and power plant 

operation (CHP or cogeneration) facilities. If the data provided 

from the industrial facility are sufficient to identify water used 

in power generation, then that amount of water and the power 

generated are compiled with other county thermoelectricpower water-use data. 

Data Elements

The category of thermoelectric power consists of the 

following mandatory and optional data elements. Data for the 

optional elements may be compiled and entered into AWUDS, 

but will not be part of the national water-use analysis for 2005 

as published in the water-use circular series. The optional data, 

however, will be available for other types of water studies. 

20 Guidelines for Preparation of State Water-Use Estimates for 2005
Mandatory

Ground-water withdrawals, once-through cooling, 

freshwater, by county

Ground-water withdrawals, once-through cooling, 

saline water, by county

Surface-water withdrawals, once-through cooling, 

freshwater, by county 

Surface-water withdrawals, once-through cooling, 

saline water, by county

Ground-water withdrawals, closed-loop cooling, 

freshwater, by county

Ground-water withdrawals, closed-loop cooling, 

saline water, by county

Surface-water withdrawals, closed-loop cooling, 

freshwater, by county

Surface-water withdrawals, closed-loop cooling, 

saline water, by county

Power generated, once-through cooling, by county

Power generated, closed-loop cooling, by county

Optional

Deliveries from public supply, once-through cooling, 

by county

Deliveries from public supply, closed-loop cooling, 

by county

Consumptive use, once-through cooling, freshwater, 

by county

Consumptive use, once-through cooling, saline water, 

by county

Consumptive use, closed-loop cooling, freshwater, 

by county

Consumptive use, closed-loop cooling, saline water, 

by county

Number of facilities, once-through cooling, by county

Number of facilities, closed-loop cooling, by county

Reclaimed wastewater, once-through cooling, 

by county

Reclaimed wastewater, closed-loop cooling, by county

Any data aggregated by hydrologic cataloging unit

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Sources of Information

For each USGS Water Science Center, the documentation 

for the previous compilations should be the starting point 

for planning the data collection for the 2005 compilation. 

The previous documentation for the thermoelectric-power 

category may contain the location and types of electronic 

and paper files; agency and contact information; agency and 

Internet resources; and methods, techniques, and coefficients 

used to collect or estimate data. Additional information 

concerning thermoelectric-power use may be obtained from 

the following sources. Other sources of information may be 

available in each State. 

The NWUIP will provide a data file with average daily 

water withdrawals, water releases, consumptive use, and net 

power generated by thermoelectric power plants and cooling 

type and net power generated by CHP plants, respectively, 

in million gallons per day and giga-watt hours. The source 

of data for the derivative data file is the USDOE–EIA (U.S. 

Department of Energy–Energy Information Administration) 

electricity databases. USDOE–EIA maintains site-specific 

data for thermoelectric power and CHP plants with a nameplate rating of 10 megawatts or more. Since 2001, nuclearfueled power plant data have not been collected through the 

water survey (EIA-767). However, nuclear-fueled power plants 

are included in the files that have power-generated (EIA-906) 

data and that available data will be included in the USGS 

derivative data file. 

Agencies or Other Entities

Possible contacts for thermoelectric-power water-use 

data are listed as follows. Water-use data from these sources 

can range from reported water withdrawals to coefficients and 

ancillary data that can be used to estimate water withdrawals 

and power generation by cooling system type. Multiple data 

sets can be used to determine the best estimates and provide 

QA/QC. 

State agencies that administer water rights, allocate 

water to users, or collect water-use data 

State agency responsible for compliance with 

USEPA’s Clean Water Act Program through the 

NPDES and PCS.

State agency for power administration

Regional “power pools” (groups of electric 

utility companies)

Individual facilities 

Public suppliers (for deliveries)

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Thermoelectric Power 21
Internet Resources

Many agencies and other entities maintain thermoelectricpower water-use information and databases on the Internet. 

Specific Internet addresses are listed as they appeared on the 

date last accessed. 

U.S. Department of Energy (DOE), accessed June 6, 

2006, at <http://www.energy.gov>

Energy Information Administration (EIA, part of DOE), 

accessed June 6, 2006, at <http://www.eia.doe.gov/>

List of EIA electric power forms, accessed June 6, 

2006, at <http://www.eia.doe.gov/oss/forms.html>

This list includes contact information for each type 

of report.

EIA-906 (Monthly Utility Power Plant Database 

report, formerly EIA-759)—net generation, fuel 

type; monthly data for plants with nameplate capacity of 50 megawatts or more, annual data for plants 

with nameplate capacity of less than 50 megawatts, 

accessed June 6, 2006, at <http://www.eia.doe.

gov/cneaf/electricity/page/eia906u.html>

EIA-767 (Annual Steam-Electric Plant Operation 

and Design Data)—net generation, fuel type, cooling-water process/source/rate; only plants with generating capacity of 10 or more megawatts, accessed 

June 6, 2006, at <http://www.eia.doe.gov/cneaf/

electricity/page/eia767.html>

EIA-920 (Combined (Utility, Non-Utility, and Combined Heat & Power Plant)––monthly and annual 

data on generation and fuel consumption at the 

power plant and prime mover level. Data for utility 

plants are available from 1970 and for non-utility 

plants from 1999. Beginning with January 2004 data 

collection a new form, the EIA-920, has been used 

to collect data from the combined heat and power 

plant (cogeneration) segment of the non-utility sector, accessed June 6, 2006, at <http://www.eia.doe.

gov/cneaf/electricity/page/eia906_920.html>

Energy data for each State (summaries, profiles, 

graphics), accessed June 6, 2006, at <http://www.

eia.doe.gov/emeu/states/_states.html>

USEPA, accessed June 6, 2006, at <http://www.epa.gov/>

Water Discharge Permits, PCS database, accessed 

June 6, 2006, at <http://www.epa.gov/enviro/html/

pcs/pcs_query_java.html>

Access to data regarding facilities holding NPDES 

permits. Specify the facilities by using any combination of facility name, geographic location, SIC code, 

and chemicals.

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Compilation Techniques

Most water for thermoelectric use is self-supplied from 

freshwater or saline surface-water sources. Smaller quantities 

are derived from ground-water sources or provided by public 

suppliers. The recommended approach for compiling data for 

thermoelectric power is to use site-specific water-withdrawal 

data and power-generation data. Site-specific data can be that 

from USDOE–EIA (with the exception of nuclear-fueled power 

plants) that will be provided by the NWUIP, or can be collected 

from other sources. Federally mandated information collected 

and maintained by the USDOE–EIA, includes power-plant 

ownership, location, method of cooling, sources of water, 

average withdrawal rates, average discharge rates, operating 

status, and power generated. This information is collected from 

monthly and annual surveys of power plants. Information on 

net power generation and energy source may be found in the 

EIA-920 combined utility, nonutility, and combined heat and 

power plant database, formerly and successively, EIA-906 and 

EIA-759. Beginning with January 2004 data collection, the 

EIA-920 has been used to collect data from the CHP plants. 

EIA-767, Annual Steam-Electric Plant Operation and Design 

Data, contains cooling water information for all natural gas and 

fossil- and biomass-fueled plants with a generator nameplate 

rating of 10 or more megawatts. Average rate of water withdrawal, water release, and consumptive use to the nearest cubic 

foot per second by cooling system type for each generator and 

power plant are included in the EIA-767 database. 

Water-withdrawal and power-generation data for the 

nuclear–fueled power plants and for the smaller plants with a 

generator rating of less than 10 megawatts will have to be collected using a different approach such as contacting the individual utility. If the contact person for a utility is not known, 

a good place to start is the person at the utility who prepares 

the Discharge Monitoring Reports (DMRs) for USEPA. DMRs 

contain information on volume discharged from all pipes 

in the facility and can be compared to the permit or permit 

application as to the source of the water and how it was used. 

The following selected terminology may help in conversations 

with utility personnel—blowdown, capacity, drift, and makeup 

water. These terms are defined in the Glossary section.

State agencies that administer water rights or monitor water use may have water-withdrawal information. The 

State agency that is responsible for compliance with USEPA’s 

Clean Water Act is an important source for this information. 

USEPA administers the PCS database, which was designed 

to track permit, compliance, and enforcement status data for 

the NPDES program under the Clean Water Act. An NPDES 

permit is required for all point discharges into U.S. waterways. 

The PCS database contains descriptive information on major 

power-generating facilities, their location, and monthly return 

flows. The NPDES permit application and the permit itself 

usually include detailed descriptions of the plant that provide 

basic information on all the sources of supply for the plant, the 

different ways in which water is used in the plant, and water 

included in the reported discharge values.

22 Guidelines for Preparation of State Water-Use Estimates for 2005
Power-generation data can be used to estimate thermoelectric-power water withdrawals. A coefficient to estimate the 

gallons of water used per unit-hour of electricity generated is 

calculated using information on water withdrawals and power 

generation from plants of similar age, design, and cooling methods. This coefficient then can be multiplied by the 

amount of electricity generated during a specified time period 

by the plant for which withdrawals are being estimated. Coefficients ideally are derived using the gross power produced, if 

available. Monthly net power generation, in megawatt-hours, 

is available in the EIA-920 database but does not include the 

electricity used to run the power plant itself. The in-power 

plant electricity use that can be added to the net power is 

available from other EIA databases, but will not be part of the 

NWUIP derivative data file provided to the study chiefs. 

References

Allen, R.G., Pereira, L.S., Raes, Dirk, and Smith, Martin. 

1998, Crop evapotranspiration—Guidelines for computing crop water requirements: FAO irrigation and drainage 

paper 56, Rome, Italy. 

Arvin, D.V., 1992, Feasibility of using portable, noninvasive 

pipe flowmeters and time totalizers for determining water 

use: U.S. Geological Survey Water-Resources Investigations 

Report 91-4110, 65 p.

Dash, R.G., Troutman, B.M., and Edelmann, Patrick, 1999, 

Comparison of two approaches for determining groundwater discharge and pumpage in the lower Arkansas River 

Basin, Colorado, 1997–98: U.S. Geological Survey WaterResources Investigations Report 99-4221, 39 p.

Helsel, D.R., and Hirsch, R.M., 1995, Statistical methods in 

water resources: New York, Elsevier, Studies in Environmental Science 49, 529 p.

Hurr, T.R., and Litke, D.W., 1989, Estimating pumping time 

and ground-water withdrawals using energy-consumption 

data: U.S. Geological Survey Water-Resources Investigations Report 89-4107, 27 p.

Hutson, S.S., Barber, N.L., Kenny, J.F., Linsey, K.S., 

Lumia, D.S., and Maupin, M.A., 2004, Estimated use of 

water in the United States in 2000: U.S. Geological Survey 

Circular 1268, 46 p.

Kenny, J.F., ed., 2004, Guidelines for preparation of State 

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24  Guidelines for Preparation of State Water-Use Estimates for 2005
Supplemental Information

Coding Forms

The coding forms represent data matrices showing the 

category names as columns and the associated data elements 

as rows. The cells or boxes on the forms are either open or 

closed; a closed box is black and indicates that data cannot be 

stored in AWUDS for the data element corresponding to that 

cell. The forms are not intended to be used as manual coding 

forms, but as references summarizing the scope of the 2005 

water-use compilation. The first form shows the data elements 

required for all States at the county aggregation level. There 

are no mandatory data elements for aquifers or Hydrologic 

Unit Codes (HUC) for 2005, and no state-level aggregations 

are allowed. The second, third, and fourth forms show all data 

elements supported in the Aggregate Water-Use Data System 

(AWUDS), with mandatory elements shaded in yellow, mandatory but null values allowed elements in yellow stripes, and 

optional elements in blue. Note that for irrigation, subdividing 

Irrigation into Crop Irrigation and Golf Course Irrigation

is optional. If Golf Course Irrigation is not subdivided as a 

separate category, water use for golf course irrigation must be 

included in the Irrigation estimate. 

Mandatory Data Elements for County

ESTIMATED USE OF WATER IN THE UNITED STATES

2005 Data Collection Form

County Name: County Code: Total Population (000s) †

Thermoelectric

Data Element

Public 

Supply Domestic Industrial Oncethrough

Closedloop Mining Livestock Aquaculture Irrigation

Withdrawals - GW - fresh • • •

Withdrawals - GW - saline •

Withdrawals - SW - fresh • • •

Withdrawals - SW - saline •

Population served - Total (000s)

Deliveries from public supply

Power generated (gigawatt-hours)

Acres irrigated - sprinkler (000s)

Acres irrigated - micro (000s)

Acres irrigated - surface (000s)

Reclaimed wastewater

† Data will be provided by the National Water Use Program for all States.

• Data will be provided by the National Water Use Program for all States: States may make independent 

estimates if desired

Supplemental Information 25
Data Elements for County

MandatoryMandatory but null values allowedNon-mandatory

ESTIMATED USE OF WATER IN THE UNITED STATES

2005 Data Collection Form

County Name: County Code: Total Population 

Thermoelectric Irrigation (Crop/Golf is optional) 

Data Element

Public 

Supply Commercial Domestic Industrial Once- through Closed- loop Mining Livestock Aquaculture Total Crop irrigation Golf-course irrigation In

Instream water useWithdrawals - GW - fresh • • •Withdrawals - GW - saline •Withdrawals - SW - fresh • • •Withdrawals - SW - saline •Population served - Total (000s) Population served - GW (000s) Population served - SW (000s)Deliveries from public supplyConsumptive use - freshConsumptive use - salineConveyance lossPower generated (gigawatt-hours)Acres irrigated - sprinkler (000s)Acres irrigated - micro (000s)Acres irrigated - surface (000s)Facilities (number)Wastewater returns-public facil.Reclaimed wastewater

† Data will be provided by the National Water Use Program for all States.

• Data will be provided by the National Water Use Program for all States: States may make independent estimates if desired
Data Elements for Aquifer

Aquifer Name: Aquifer Code: Total Population (000s):

Thermoelectric Irrigation (Crop/G

Data Element

Public 

Supply Commercial Domestic Industrial Once- through Closed- loop Mining Livestock Aquaculture Total Crop 

tio

Withdrawals - GW - freshWithdrawals - GW - salinePopulation served - GW (000s)
Data Elements for Eight-Digit Hydrologic Unit Code

ESTIMATED USE OF WATER IN THE UNITED STATES

2005 Data Collection Form

HUC Name: HUC: Total Population (000s):

Thermoelectric Irrigation (Crop/Golf is optional) Hydroele

Data Element

Public 

Supply Commercial Domestic Industrial Once- through Closed- loop Mining Livestock Aquaculture Total Crop irrigation Golf-course irrigation Instream O

Instream water useWithdrawals - GW - freshWithdrawals - GW - salineWithdrawals - SW - freshWithdrawals - SW - salinePopulation served - Total (000s) Population served - GW (000s) Population served - SW (000s)Deliveries from public supplyConsumptive use - freshConsumptive use - salineConveyance lossPower generated (gigawatt-hours)Acres irrigated - sprinkler (000s)Acres irrigated - micro (000s)Acres irrigated - surface (000s)Facilities (number)Wastewater returns-public facil.Reclaimed wastewaterReservoir surface area (thous. ac)Reservoir evaporation (thous ac-ft)