Water Utilization:
An Analytical White Paper
Executive Summary
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WaterUtilization:AnAnalyticalWhitePaper
ForNCGAbyDr.J.McLaren,StrathKirnInc.
CONTENT
1.
2.
3.
4.
5.
DefiningtheBasicIssueandtheGlobalWaterSituation
OverallUSWaterSituation(SupplyandUtilization)
CornWaterUtilization
FutureNeeds&Issues
References&Appendix
1. DefiningtheBasicIssueandtheGlobalWaterSituation
Trendsinwaterutilizationareshowingthatcontinuousimprovementisnowunderwayinmany
countries,yetnumerouschallengesremainintherealmofwater.Forexample,someofthetopissues
include:populationpressures,infrastructureneeds,foodproductionandagriculturalchanges,energy
generation,aneverchangingclimate,andenvironmentalconcerns.Whiletheseissuesareimportant,
anddeserveattention,thereisalargerunderlyingproblemrelatedtowaterinthatthefundamental
watersituationisnotwelldefined,thedataisnonuniform,thedefinitionsarevaried(andoften
technicallyinaccurate),andwaterisoftenapoliticalhammerwhichleadstoemotionalstatementsand
actions.And,asillogicalasitsounds,allofthisonaplanetwherewatercovers~70%ofthesurface.
Inordertodevelopsolutionstoaproblemitisfirstimportanttoproperlydefinethesituationinrealistic
terms,andtoidentifythetoppriorityissuesforresolution.Humanstalkalotabout“wateruse”but
whatdoesthatreallymean?Areweremovingwaterfromtheplanet?Arewechangingitintosomething
else?Or,arewejustmovingitaroundfromplacetoplace?AccordingtoConnoretal(2009),common
definitionsaroundwaterinclude:
x
x
x
x
Waterusereferstowaterthatisbeingputtobeneficialusebyhumans.Detailedwater
accounting,however,requiresmoreprecisedefinition.
Waterwithdrawalisthegrossamountofwaterextractedfromanysourceinthenatural
environmentforhumanpurposes.Differentiatingwithdrawalsbytypeofsourceisusefulto
understandthepressureputondifferentpartsofthesystem.
Waterdemandisthevolumeofwaterneededforagivenactivity.Ifsupplyisunconstrained,
waterdemandisequaltowaterwithdrawal.
Waterconsumptionorconsumptiveusereferstothatpartofwaterwithdrawnthatis
evaporated,transpired,incorporatedintoproductsorcrops,consumedbyhumansorlivestock,
orotherwiseremovedfromtheimmediatewaterenvironment.
Whilethesedefinitionsareagoodstartandhelpsetacommonbaseline,inmostsituations“wateruse”
or“waterconsumption”isnotthetechnicalequivalentofwaterbeingchemically,orreactively,
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removedfromtheenvironment,andthisaspectisnotdefined.Forexample,inindustrialprocesses
watermaybeutilizedinachemicalreactiontomakeaparticularproduct(e.g.hydrationofapolymer
forplasticfilm)or,alternatively,insomesituationsitmaybeutilizedforcoolingandthenberecycled.
Inonesituationwaterisused(noteasilyrecoverable)andintheothercasewaterisutilizedbymovingit
fromoneplaceintheenvironmenttoanotherplaceintheenvironment.Inagriculture,watermaybe
“used”inphotosynthesis,whereH2Oisphysicallysplitintohydrogenandoxygenandthehydrogenis
incorporatedintofixedcarbonbasedmaterialsforfoodandenergy.Or,formostcropsituations,water
ismovedinanaturalprocesscalledevapotranspiration,wherewatermovesfromthesoiltotheairvia
theplanttissuesresultinginacoolingeffect.Incaseofphotosynthesis,wateris“used”andis
permanentlyremovedfromthetotalwaterpool,whileinthecaseofevapotranspirationwaterismoved
fromoneplacetoanotherintheenvironment.
Therefore,theinterventionofhumansdoesnotreallycauseproblemswiththe“use”ofwater,but
ratherwiththemovementofwaterfromoneplacetoanother,andwiththerateatwhichthatwater
moves.Thesolutionstoeachoftheseissuesarelikelytobequitedifferent.
Innature,watercanbefoundasasolid(ice),liquid,orgas,andiscontinuallymovingamongthetypes
andfromoneplacetoanother.Thisprocessiscalledthehydrologicorwatercycle:
Waterevaporatesfromtheoceanand,asitreachescooleraltitudes,thevaporcondensestoform
clouds.Cloudsmaymovearoundbutwithinafewdaysthewaterreturnstothesurfaceasprecipitation.
Muchoftheprecipitationreturnsthewaterdirectlytotheocean,butabout25%fallsoverland.From
theground,watermayevaporateagain,orpenetratethesurfaceandbea)takenupbyplantsandmove
backintotheatmospherebytranspiration,b)enterintotheriver/lakesystemtobeevaporatedor
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carriedbacktotheocean,orc)bestoredformanyyearsinundergroundaquifers.Ingeneral,thereis
continuousmovementofwater,buttheactualratesofmovementandresidencetimeinvarious
locationsdependonseveralfactors,includinganthropogenicintervention.Forexample,theaverage
residencetimeintheatmosphereis79dayswhileundergroundaquiferresidencetimecanbeover
100,000years.
Thesizeofthevariouslocationreservoirsisalsoimportant,andmeaningfulrelativetotheflux(outand
in)rates,andhowtheseareimpactedbyhumanactions.Currentestimates(Gleick,1996)putthe
world'stotalwatervolumeat~332.5millioncubicmiles,with~97%beingsaltwater.Ofthe~3%total
freshwater,abouttwothirdsisheldiniceandglaciers,and~30%isintheground.Rivers,lakesand
otherfreshwatersurfacevolumesareonly~23,000cubicmiles(0.007%total),yethumanstendto
focusonthissmallamountofwaterratherthanonthemassivevolumesinotherlocations.These
relativevolumesaredepictedinthefollowingdiagram:
Rivers
100%
Swamps
80%
40%
100%
Ground
80%
Fresh
100%
20%
0%
60%
Ice
40%
80%
Surface
23 K miles3
~0.007% total
20%
60%
Saline
Lakes
60%
Surface
.
0%
40%
Freshwater
20%
10 MM miles3
~3% total
0%
Earth
332 MM miles3
Intheabovediagram,thecirclesprovideavisualrepresentationofthelargesizedifferencesinvarious
locations,andthenumberprovidesanestimateofthetotalvolumesincubicmiles.
Inadditiontothelargedifferencesinlocationpoolsizes,itisimportanttounderstandtheflowrates
betweenthevariouslocations.Thefollowingdiagramprovidesaglobalestimate(WW2010,2009)ofthe
mainflowratesbetweenmajorwaterlocations,anddemonstratesthebalanceachievedinthe
hydrologiccycle:
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Atmosphere
0.013 X 1015 m3
Evaporation
361 X 1012 m3
Evapotranspiration
62 X 1012 m3
Precipitation
324 X 1012 m3
Precipitation
99 X 1012 m3
Land
34 X 1015 m3
Oceans
1,350 X 1015 m3
Runoff
37 X 1012 m3
Onaglobalscalethelocationsizesremainconstant,withtheevaporationbeingbalancedbythetotal
returnvolumesviaprecipitationandrunoff.Notethatwaterdoesnotdisappear:i.e.itisnot“used”but
rathermovesfromlocationtolocation.Theenergyrequiredtodrivethemovementaroundthe
hydrologiccycleisobtainfromthesun.
Transpirationisthemovementofwaterthroughaplant,tocarrynutrientsandgeneratecooling,and
accountsforabout10%ofallevaporation.Watermovementawayfromafieldsurfacecanbevia
leaching,evaporation,ortranspiration:inmanysituationsthesearecombined,andcalled
evapotranspiration.Theprocessofphotosynthesisdoes“use”asmallamountofwaterbutthisisnot
measurableontheglobalscale.
2. OverallUSWaterSituation
Supply&Reserves
Ithasbeencalculatedthat,onaverage,the48continentalstatesreceiveenoughprecipitationinone
yeartocoverthelandtoadepthof~30inches(USGS,2009).Thisexamplesuggeststhatthereisnoreal
shortageofwaterfallingintheUSbut,inreality,showshowaveragescanbemisleading.
Clearly,theoverallUSprecipitationisconsiderablebutdoesnotoccurinauniformdistribution,and
evaporationisnotuniform,leadingtosomewetareascontrastedwithdryareasacrossthecountry(see
chartsbelow).However,thisexampledoeshighlightthepointthatwaterissuestypicallyarisedueto
locationratherthantotalvolume.Theadditionaldimensiontobeconsideredistime,sinceprecipitation
andflowratesbetweenlocationsmayvaryovertime.
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Theannualaverageprecipitationtrend,overthepastcenturyintheUS,showsaveryslightincreasein
rainfall(approx0.17inch/decadeincrease):asshowinthefollowingchartwithdatafromNCDC(2009):
Century average = 29.19 inches/yr
Trend line = 0.17 inches/decade
Thedistributionofprecipitationisdemonstratedbymappingtheannualaveragerainfallover18902002
(Reillyetal,2008):
Annual average rainfall 1890-2002
Thisprecipitationistheresourcethatcurrentlyaccountsforevapotranspiration,runoffviastreams,and
rechargeoflakesandgroundwateraquifers.Thus,itisnotallavailableforinterceptionbyhumans.The
followingchartshowsanestimateoftheprecipitationavailableforrunoffandrecharge,over1943
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2002:calculatedasthedifferencebetweenmonthlyprecipitationandmonthlypotential
evapotranspiration,thensummingthenonzeromonths(Reillyetal,2008):
Monthly rainfall minus evapotranspiration
Summed over non-zero months
Runoffimpactsstreamflowwhichishighlyvariableforanyparticularlocationovertime.Realtimedata
isnowavailabletotracksuchchanges(USGS,2009),forexample:
Real-time stream flow compared to historical daily flow
Theestimatedaveragewateravailableforrecharge(Reillyetal,2008)hasbeenestimated(not
necessarilyaccurateforallconditionstoday,butgivesanapproximationofthedistribution).This
potentialrechargecapabilitycanbecomparedtothelocationsofthegroundwateraquifers,asshown
inthenexttwocharts:
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Distributionoftheaverage
availablewaterforrecharge.
[At1kmresolutionandforthe
period19511980].
TheUShasover60large
aquifers,withthemain30aquifersaccountingfor~94percentofthetotalgroundwaterwithdrawals
forpublicsupply,irrigation,andselfsuppliedindustrialusescombined:
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OtherwaterreservesincludetheGreatLakes(sharedwithCanada),withatotalvolumeof~2,900mile3
whichis21%ofthetotalsurfacefreshwaterontheplanet.AlltheotherUSlakes,rivers,andreservoirs
areestimatedat2,540mile3.However,fromthepreviousdistributionchartsitisclearthatmostofthe
lakeresourcesarenotinareaswherewaterdeficitsarecommon.MuchofthewesternUnitedStates,
exceptforsomecoastalareas,hasfarlesswateravailableforgroundwaterrechargeandusethanthe
restofthecountry.Thefollowingcharthasbeencompiledfromvariousdata(seeReillyetal,2008)and
showsareasoflittleornowaterdeficiency,areasofseasonalmoisturevariation(summerdeficiency
andwintersurplus),andareaswithlittleornowatersurplus:
Finally,thereisalargewaterresourceintheUScoastline,althoughthistendstobeignoredduetothe
salinenatureofthewater.Inthefuture,thisresourcewillbecomeakeysourcefromwhichtomove
watertoirrigate,propagate,utilize,andevenrechargetheaquifers.
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Utilization
TheUSGShascompileddataonwaterwithdrawalsbystate,sourceofwater,andcategoryofuse,at5
yearintervalssince1950(USGS,2009B).Themostrecentreportreleasedis"Estimateduseofwaterin
theUnitedStatesin2000",andmarks50yearsofwaterusedata.(notethat2005dataisstillunder
analysisandisprojectedforreleasearoundmid2009).WhileUSGSreferstowateruse,itshouldbe
keptinmindthatthiswaterisnot“used”butrather“utilized”forvariouspurposesbymovingitfrom
onelocationtoanother,orbymovingfromalocationforaperiodoftime.Therearemultiple
dimensionstowaterutilization:e.g.geographicalfactors,saline/freshwater,typeofutilization,sourceof
withdrawal,returntorechargerates,qualitychanges,andtemporalpatterns.Dealingwitheach
dimensionandtheinteractionsbetweenthefactorsresultsinhundredsofviews.Forthisreport,we
includethehigherlevelviewsforeachtypeofutilizationplussomeadditionaldetailforspecificselected
situationsandgeographies.
From1950to1980,therewasincreasingwaterutilizationandagrowingconcernthat,withpopulation
andeconomicgrowth,therewouldbealargeincreaseinthevolumerequired.However,duetowater
awareness,economicfactors,andnewertechnologiesbeingapplied,watervolumeutilizationhasbeen
aboutflatsincearound1980,despitepopulationandeconomicgrowth.Thesetrendsareshowninthe
followingchartwithdatafromUSGS(2009B),withdetailsshownintheappendix:
Atthelastofficialestimate,in2000,some408Bgal/daywerewithdrawnforallusesduringtheyear,
andthatwaslessthanin1980:waterisnowbeingutilizedmoreefficiently.Decreasesintotalvolume
occurredinthermoelectric,irrigation,otherindustrial(e.g.mining/manufacturing)applications,which
morethanoffsetincreasesinpublicsupply,ruraldomesticsupply,livestockandaquaculture.[Itwillbe
interestingtoseeifthetrendscontinuedthrough2005,whenthemostrecentdataarereleased.]
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ThermoelectricPower(50%of2000total)
NotethathydroelectricpowerisconsideredaninstreamuseandisnotincludedintheUSGSusereport.
Waterwithdrawalforcoolingatthermoelectricgenerationfacilitiesaccountsfor~50%ofthetotalwater
utilizedintheUS(~3%increasefrom1995to2000).Surfacewaterwasthesourcefor>99%ofthese
withdrawals,and~30%wassurfacesalinewater.Thefollowingchartshowsthedistribution(USGS,
2009B):
Freshandsalinewaterwithdrawalsintheeasternstateswere83percentofthetotal.Texasisthesingle
largeststateforthistypeofutilization.ThestatesaroundtheGreatLakeswithdrawahighvolumefor
cooling–theelectricitygenerationfacilitieswereoftendesignedtohaveaccesstothiswaterresource.
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PublicWaterSupply(13%of2000total)
Publicsupplyisdefinedaswaterwithdrawnbypublicandprivatewatersuppliersthatfurnishwaterto
atleast25peopleorhaveaminimumof15connections,andmaybedeliveredtousersfordomestic,
commercial,industrial,orthermoelectricpowerpurposes.Thepublicsupplywithdrawalsaremostlyall
freshwater.Publicsupplywithdrawalswere~13%oftotalwithdrawalsand~63%iswithdrawnfrom
surfacesources.Stateswiththelargestpopulationswithdrewthelargestquantitiesofwater:California,
Texas,NewYork,Florida,andIllinoisaccountedfor40percentoftotalpublicsupplywithdrawals.The
geographicdistributionofpublicsupplywithdrawalsisasfollows(USGS,2009B):
In1950,only~62%oftheUSpopulationreceivedwaterfrompublicsupplywhileby2000thathadrisen
to~85%.Thetrendtomorepublicsupplywaterisexpectedtocontinue.
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IndustrialWater(5%of2000total)
Notethatthedataforthissectionrefersto“selfsupply”industrial,whileinrealityadditionalindustrial
watermaybesuppliedviathepublicsupply.Industrialwaterutilizationwas~5%ofthetotal.Utilization
andusepurposesincludefabricating,processing,washing,diluting,cooling,ortransportingaproduct;
incorporatingwaterintoaproduct;orforsanitationneedswithinthemanufacturingfacility.Examples
ofindustrieswithlargewaterutilizationinclude:food,paper,chemicals,refinedpetroleum,andprimary
metals.In2000,surfacewaterwasthesourcefor82percentoftotalindustrialwithdrawals.Nearlyall
(92percent)ofthesurfacewaterwithdrawalsandnearlyall(99percent)ofthegroundwater
withdrawalsforindustrialusewerefreshwater.For2000,totalindustrialwithdrawalswere11percent
lessthanduring1995.Asshowninthefollowingchart(USGS,2009B),Louisiana,Indiana,andTexas
accountedforalmost38percentoftotalindustrialwithdrawals.Thelargestfreshsurfacewater
withdrawalswereinLouisianaandIndiana,whichtogetheraccountedfor32percentofthetotalfresh
surfacewaterwithdrawals.ThelargestfreshgroundwaterwithdrawalswereinGeorgia,Louisiana,and
Texas,whichtogetheraccountedfor23percentofthetotalfreshgroundwaterwithdrawals.Texas
accountedfor71percentofthesalinesurfacewaterwithdrawalsforindustry.
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Other(45%of2000total)
Miningwateruseiswaterfortheextractionofminerals,coal,iron,sand,andgravel;liquidssuchas
crudepetroleum;andnaturalgas.Thecategoryincludesquarrying,milling(crushing,screening,
washing,andflotationofminedmaterials),reinjectingextractedwaterforsecondaryoilrecovery,
andotheroperationsassociatedwithminingactivities.Allminingwithdrawalswere~1%ofthe2000
total.
Domesticwateruseiswaterutilizedforarangeofpurposesincluding,drinking,preparingfood,
bathing,washingclothesanddishes,flushingtoilets,andwateringlawnsandgardens.Waterfor
domesticusemaybedeliveredfromapublicsupplier(reportedunderpublicsupply)orbeself
supplied–typically,fromawell.Forselfsupplieddomesticwater,thewithdrawalswere~1%ofthe
2000total.
Livestockwateruseiswaterassociatedwithlivestockwatering,feedlots,dairyoperations,andother
onfarmneeds.Alllivestockwaterwithdrawalswerelessthan1%ofthe2000total.
Aquaculturewateruseiswaterassociatedwithraisingorganismsthatliveinwaterforfood,
restoration,conservation,orsport.Aquacultureproductionoccursundercontrolledfeeding,
sanitation,andharvestingproceduresprimarilyinponds,flowthroughraceways,and,toalesser
extent,cages,netpens,andclosedrecirculationtanks.Allaquaculturewaterwithdrawalswere
almost1%ofthe2000total.
Irrigation(40%of2000total)
Irrigationwaterutilizationvolumewas~40%ofthetotalandincludedwaterthatisappliedforpre
irrigation,frostprotection,applicationofchemicals,weedcontrol,fieldpreparation,cropcooling,
harvesting,dustsuppression,leachingsaltsfromtherootzone,andwaterlostinconveyance.Irrigation
ofgolfcourses,parks,nurseries,turffarms,cemeteries,andotherselfsuppliedlandscapewateringuses
alsoareincluded.Allirrigationwithdrawalswereconsideredfreshwaterand58%wastakenfrom
surfacewatersources,butthecentralstateshadthemajoritytakenfromgroundwatersources.The
averageapplicationratewas2.48acrefeetperacre,acrossthe61,900irrigatedacresreportedin2000.
Thefollowingchart(USGS,2009B)showsthatthemajorityofirrigationwithdrawals(86percent)and
irrigatedacres(75percent)wereinthe17conterminouswesternstates,especiallywhereaverage
precipitationwaslessthan20inches.Thetop5statesforirrigationvolume,inthe2000survey,were
California,Idaho,Colorado,Nebraska,andTexasandaccountedforover50%ofthetotalirrigation
waterwithdrawals.CaliforniaandIdahoaccountedfor40percentofsurfacewaterwithdrawals.
CaliforniaandNebraskaaccountedforonethirdofgroundwaterwithdrawals.
Estimatesoftotalirrigationwithdrawalsfor2000wereabout2percentmorethanduring1995.Surface
waterwithdrawalswereabout5percentlessfor2000comparedto1995,butgroundwater
withdrawalswere16percentmore.Theestimatednumberofirrigatedacreswasabout7percentmore,
whichresultedinaslightlyloweraverageapplicationratefor2000.
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About61.9millionacreswereirrigatedin2000.ApplicationratesweregreatestinthearidWestandthe
Mountainstateswheresurfacewaterwasavailableandsurface(flood)applicationwasthepredominant
methodofirrigation(29MMacres).InArizona,Montana,andIdaho,applicationratesexceeded5acre
feetperacre.statesthatutilizedtheHighPlainsaquifer(Nebraska,Texas,Kansas,andOklahoma)orthe
MississippiRiveralluvium(Arkansas,Missouri,Mississippi,andLouisiana)forirrigationreliedmostlyon
groundwaterandhadapplicationratesrangingbetween1and2acrefeetperacre.Sprinklerirrigation
(28MMacres)wasthepredominantapplicationmethodintheCentralPlainsstatesofKansas,
Nebraska,NorthDakota,Oklahoma,SouthDakota,andTexas.Californiaaloneaccountedfor72percent
oftheirrigatedacreagebymicroirrigationsystems(4MMacres).Surfaceirrigationwasthe
predominantapplicationmethodinArkansas,Louisiana,Mississippi,andMissouri.
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Otherirrigationinformation
TheUSDAcarriedoutaspecificsurveyonirrigationasasupplementtothe2007AgriculturalCensus.
TheresultswillbeavailableNovember30,2009.
CurrentUSDAInformationforallcrops
WhiletheUSGShasirrigationvolumeat61.9MMacres,theUSDAirrigationacresintherangeof5055
MMacres:webelievethedifferencehereisthatUSGSincludesgolfcoursesandotherlandscapeareas,
whiletheUSDAareaisbasedonactualcrops.TheUSDAreportsthefollowingregionalirrigationareas:
1
2
2
1997
1969
Percent
2002
Percent
Percent
1,000 acres
3
39,100
100
56,289
100
55,311
100
Eastern regions
4,200
11
12,308
22
13,288
24
Northern Plains
4,600
12
10,312
18
10,907
20
Uni ted States
1,000 acres
1,000 acres
Region or crop
Region
4
Southern Plains
7,400
19
6,273
11
5,592
10
Mountain
12,800
33
13,603
24
13,011
24
Pacific Coast
10,000
26
13,713
24
12,440
22
Corn for grain
3,200
8
10,816
19
9,710
18
Other grains
9,200
24
9,245
16
7,703
14
700
2
4,238
8
5,460
10
3,100
8
5,152
9
4,802
9
Crop
Soybeans
Cotton
Alfalfa hay
5,000
13
6,087
11
6,809
12
Vegetables and orchar
3,900
10
6,722
12
6,734
12
14,000
36
14,030
25
14,093
25
5
Other lands in farms
1
Census of Agriculture.
2
Census of Agriculture, adjusted for non-response.
3
Includes Alaska and Hawaii.
4
Northeast, Appalachian, Southeast, Lake States, and Corn Belt.
5
Other uses wi th more than 500,000 irrigated acres include corn silage, other hay, dry beans, potatoes,
sugar beets, nursery crops, cropland pasture, and other pasture.
Source: USDA, Census of Agricul ture, selected years.
Thedatasupporttheobservationthatirrigationinmostregionsisflattodownintermsofacres,except
intheEasternregionwhereirrigatedacreshaveincreasedslightlyinrecentyears.Thesetrendswereup
until2002andthe2007dataarenotyetreleasedbutweknowforexamplethat2007cornirrigated
acreswerereportedat13.2MMacres–aconsiderableincreaseover2002.
Whileacresmayhaveincreased,thevolumeofwaterutilizedforirrigationhasdeclined(orbeenflat)
since1980.Theapplicationrateperacrehasdeclined,asshowninthefollowingchart:
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Thistrendforlesswaterapplicationperacresupportsthefactthattherehavebeenconsiderable
improvementsinwateruseefficiencyacrossmostcropsectors:mostlyduetochangesinirrigation
practiceandsystems.TheUSDAdatafromspecialFarmandRanchIrrigationSurveysassociatedwith
eachagriculturalcensus(USDA,2004)alsosupportsthistrendasfollows:
System
1979
1998
2003
Change
Change
1979-98
1998-2003
Percenta
Million acres
b
All systems
50.2
52.6
8
-3
Gravity-flow systems
31.2
26.8
23.1
-14
-14
Sprinkler systems
18.4
24.6
26.9
34
9
Center pivot
8.6
18.5
21.3
115
15
54.2
Mechanical move
5.1
3
2.7
-41
-10
Hand move
3.7
1.9
1.7
-49
-11
1
1.2
1.2
20
0
(drip/trickle and micro-sp
0.3
2.2
3
633
36
Subirrigation
0.2
0.6
0.3
200
-50
Solid/permanent set
Low-flow irrigation
a
Numbers in ( ) indicate a decrease.
Based on USDA-NASS 2004 revised estimate for 1998 due to re-weighting for
undercoverage. (The sum of subcategories will differ slightly from aggregates because of
rounding error.)
Source: USDA-ERS, based on Farm and Ranch Irrigation Surveys
Themaintrendsinthedataindicatethatgravityflowsystemshavebeendeclining,lowflowtype
systemshavebeenincreasing,andsubirrigationhasbeenhighlyvariable(lowbaseacres).Thetotal
acresreportedasirrigatedinthisdataislessthantheUSDAreportedinthecensusdata,andweare
uncertainwherethedifferentialarises.Therefore,weusethecommonlyquoted55MMacresforcrop
irrigationacrosstheUS.Thedistributionofallagriculturalirrigationis:
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Distribution of irrigated land in farms, 2002.
Total area is estimated at ~55 MM acres
Thedistributionofirrigationbycropintermsofacresandinrelationtothe%oftotalharvested
acresisasfollows:
MM acres, irrigated
As % of total harvested acres
15%
14
12
10
33%
8
8%
6
80%
26%
7%
66%
4
13%
2
0
Cornhasthehighestnumberofacresirrigatedbutitisarelativelylowpercentofthetotalcorn
acresharvested.
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Othernotesonoverallirrigationofcrops
TheUSDAoftenquotesirrigationasbeing“80%ofconsumptivewateruse”whichisamisleading
numberbasedonthedefinition–whichexcludeswaterutilizationinthermoelectricsituations.Aswe
sawfromtheUSGSwatervolumedata(previouscharts),thermoelectricisactuallythelargestvolumeof
waterwithdrawalsand,whenthatisincludedthenirrigationaccountsfor~40%ofthewatervolume
utilizedacrossthecountry(yr2000numbers).
NOTE:thetotalwithdrawalsofwaterforirrigationcanbecalculatedas:
61,900,000acresX2.48acrefeet=153,512,000acreft/year
TheUSDAestimatesthat,asawhole,theUShasabundantfreshwatersupplies.Annualrenewable
suppliesinsurfacestreamsandaquiferstotalroughly1,500millionacrefeetperyear(maf/yr).
Onaggregatetherefreshvolume(streamrunoffplusaquiferrecharge)is10Xhigherthanthewater
withdrawalvolume.Wheredoesthatwatergo?Eitherrechargeorrunoffexcesstothesea.
Ofcourse,aspointedoutbytheUSDA,anabundanceofwaterintheaggregatebeliesincreasingly
limitedwatersuppliesinmanyareas,reflectingtheunevendistributionoftheNation'swaterresources.
InthearidWest,morethanhalfoftherenewablewatersuppliesareconsumedundernormal
precipitationconditions.Indroughtyears,wateruseoftenexceedsrenewableflowthroughthe
increaseduseofwaterstoredinaquifersandreservoirs.Whiledroughtsexacerbatesupplyscarcity,
waterdemandscontinuetoexpandwithresultingreallocationsamonguses(e.g.urbangrowth).
Inotherwords,watersupplymaybeanissuebutthisonlyarisesinparticularareasforparticularcrops
withparticulartypesofirrigationandisnotauniversalnationalproblem.
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3. CornWaterUtilization
Irrigatedcornarea
Theestimatednumberofacresforirrigatedcornvariesbetweenreports:USDAdatabasedonthe
CensusofAgricultureestimatesthat~15%ofcornacresreceiveirrigation,andvariousUSGSdata
indicatethatirrigatedcornis~15%oftotal.Thedistributionofacresisasfollows:
Irrigated corn, 2002 census
Irrigated corn, 2007 census
1 dot = 2000 acres
Total = 13.16 MM acres
15% of harvested area
Total = 9.71 MM acres
14% of harvested area
ThemajorityofirrigatedacresareinNebraska,Kansas,andNTexas,roughlyfollowingthepositionof
theHighPlainsaquifer,andthePlatteRiverinNebraska.Smallerareasofintenseirrigationalsooccurin
California,Michigan,andalongtheMississippiriversystem.
Normalneedsofcorn(focusonNebraskasinceithaslargestirrigationarea)
Cornrequireswaterforgermination,photosynthesis,cellturgor,andtranspiration(watermovementto
theatmosphereviamovementthroughthegrowingplant).Oftheseprocesses,onlyphotosynthesis
actually“uses”water(togenerateoxygenandhydrogen).Transpirationinvolvesthelargestvolume
utilizationofwater,coolingtheplantasitmovesthroughandbacktotheatmosphere.Some
evaporationofwateroccursatthesoilsurface,especiallypriortocanopyclosure:thisistypically
includedinthetotalwaterreturntotheatmosphereandiscalledevapotranspiration(ET).
WhileNebraskahasalargeareaofirrigatedcorn,thisdoesnotmeanthatallthoseacresmustreceive
100%oftherequiredwaterfromirrigation.Thereisanoptimumvolumeofwaterrequiredandthisis
calculatedbasedonETneed,rainfall,andsoilholdingcapacity(Nebguide,1996).Toomuchirrigation
hasacostpenaltyandcanmovenutrientsoutoftherootzone,toolittleirrigationresultsinahighyield
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penalty.TheyieldimpactofreachinganoptimumETisshowninthefollowingchartofcornyield,
irrigationandET,inNebraska:
TheoptimumETforcorninNebraskaranges
from23”(West)to28”(East).SpecificET
Irrigation(in)
0
ET(in)
13.5
valuesarepublishedforspecificlocations.
GrainYield(bu/ac)
59
(SeeNebguide,1996)
Grain/ET(bu/acin)
4.3
Intermsofproduction,thistranslatesto4.3bu/infordrylandand7.1bu/inforirrigationuptothe
maximumrequiredETamount.Theinterestingoutcomeofthisdataisthatunderdrylandconditionsthe
cornplantisstressedtothepointofbecominginefficientinproduction.Theadditionofevensome
irrigationwateractuallyincreasestheefficiencyofwaterutilization(lesswaterperunitofgrain
produced),asshowninthefollowingchart:
Full
Limited
Irrigation Irrigation
6
13.8
19.1
25.3
135
178
7.1
7.1
Dryland
Water Utilization (ET):
gal per bu grain
Increased
water used
efficiency
Corn yield in bu/acre
59
7000
6000
178
135
5000
4000
3000
2000
1000
0
Irrigation =
Dryland
0
Limited
6”
Full
13.8”
Inthiscase,irrigatingtofullETrequirementprovidedthehighestgrainyieldandrequiredthelowest
amountofwaterperunitgrainproduced.Irrigationactuallyimprovedtheutilizationofwaterunder
conditionswhereETwasnotmetfromsoilwateralone.
Thecornthatisirrigated,acrosstheUS,onaveragereceives~10acreinchesofirrigationwater(~750
gal/acre/day,ifcorngreweverydayoftheyear.)Ifthatsamewaterwereappliedtoallcornacresit
wouldrepresent1.5acinadditionalwater:putincontextthisisonlyabout3%oftheaveragerainfall
oneachacreofcorngrown.
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AllwaterrequiredtooptimizeETneedreturnstotheatmospherewhere,within19days,itreturns
againasprecipitation.Thus,theissueofnotthatgrowingcorn“uses”water,itonlyborrowsthewater
forashorttime.Theonlyissuethatmightbecomeimportantisthatsomeirrigationwaterismoved
fromtheundergroundaquifertotheatmosphereatafasterratethanwouldotherwiseoccur.Thenthe
rateofrechargeoftheaquiferfromprecipitationandrunoffalsobecomesimportant(seesectionon
HighPlainsAquifer).
Forcomparison:overthecourseofagrowingseason,eachcornplantwillmoveabout14gallonsof
waterthroughitselfandbackintotheatmosphere.AtypicalpersoninAmericawilldrinkmorethanthat
amounteverymonth.
Offtake
WhileETmoveswatertotheatmosphere,asmallamountofwateristakenwiththeharvestedcrop.
Typically,1420%ofthegrainweightismoisturecontent.Thisamountisequalto~150galH2O/acre
corngrown,whichisA)asmallamount,B)availableforutilizationintheprocesswherecornisused
(livestockfeedorfuel/industrialprocessing).Some2Bgalwaterisexportedinthecorngrainandthis
relativelysmallamountcouldbeconsideredtobe“used”sinceitisremovedfromthenationalwater
budget(butstillremainsintheglobalwaterpool).
Processing
Muchhasbeenmadeofthewater“use”duringthecommercialprocessofgeneratingethanolfromcorn
grain.Again,thevastmajorityofthiswaterisnot“used”butisutilizedtofacilitatethefermentation
process.Watertreatmentandanevergrowingvolumeofrecycledwateratethanolfacilities,minimizes
thevolumethatutilized.Thefollowingchartshowsthecomparativeutilizationinprocessing:
Comparative utilization of water
Refining one barrel of oil
One pound of plastic
One pound of chicken
One foot-board lumber
Pre-2000 ethanol plants
Current ethanol plant
New ethanol plant
0
10
20
30
40
50
60
Gallons of water to facilitate the production of
one gallon of ethanol or the unit product noted
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Anotherperspectiveonthisisthatmostethanolisusedastherequiredoxygenateforoctanevalueand
cleaningburninggasoline,whichmeansthatover95%ethanolisusedinE10blends.Onegallonof
formulatedgasolinerequires~27.5galwatertoproduce.Therelativeproportionsofthatprocesswater
areasfollows:
The process for making one gallon of
formulated gasoline requires water.
The relative amount of water utilized is:
From making
ethanol
Related to oil
Whilemakingethanolfromcornrequireswater,thecomparativeamountutilizedisrelativelysmalland
theamountthatis“used”isnegligible.
HighPlainsAquifer
ThemajorityofirrigatedcornliesovertheHighPlainsaquiferandtheremovalofwaterwithoutanyre
chargecouldbealongtermissue–forfutureirrigationofcornitselfandforotherremovalneeds.
UnderstandingthesituationanddynamicsoftheHighPlainsaquiferisimportantforfutureactions.
TheHighPlainsaquiferlaysunder8statesandhasanestimatedareaof174,000mile2.Theirrigated
landoverthisaquiferrepresents~27%ofthetotalUSirrigatedarea,andtheaquifersupplies~30%of
thetotalirrigationwaterutilized.Theaquiferalsoprovidesdrinkingwatertoover80%ofthepeople
livingabovetheaquiferboundary(~2.5MMpeople).
TheHighPlainsaquiferwascreatedprimarilybyageologicalunitcalledtheOgallalaFormation
(NebraskaSandHillsandalluvialdeposits),whichunderlies~80%oftheHighPlains.Saturatedthickness
oftheHighPlainsaquiferrangesfrom0tomorethan1,000feetinNebraska,withanaverageofabout
200feet.Depthtowaterrangesfrom0to500feet,withanaveragedepthofabout100feet.Ground
watergenerallyflowsfromwesttoeastanddischargesnaturallytostreamsandspringsandby
evapotranspirationinareaswherethewatertableisnearthelandsurface.Pumpingfromnumerous
irrigationwellsacrosstheareaalsocontributestogroundwaterwithdrawal.Currently,precipitationis
theprincipalsourceofrechargetotheaquifer.Thelocationis:
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HighPlainsgroundwaterisutilizedprimarilytogrowcropsforthenation;irrigationaccountsfor94
percentofthegroundwateruse.Thesecondlargestgroundwateruse,418milliongallonsperday
(MMgal/day),isfordomesticdrinkingwater.Almost2millionpeoplerelyontheHighPlainsaquiferfor
theirdrinkingwater.Surfacewaterisusedfordrinkingwaterprimarilyinthelargercitiesnearthe
peripheryoftheHighPlainsaquifer(Cheyenne,Wyoming,andLubbock,Odessa,andAmarillo,Texas).
Otherutilizationofaquiferwaterincludeslivestock(222MMgal/day),mining(210MMgal/day),and
industry(155MMgal/day).TheirrigationresultsinatypicalHighPlainsscene:
Irrigation well from the aquifer
Center Pivot
Typical irrigated area
TheUSGShasmadestatementslike:
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“RegionalvariabilityofwaterlevelchangesintheHighPlainsaquiferresultsfromlargeregional
differencesinclimate,soils,landuse,andgroundwaterwithdrawalsforirrigation.Withdrawalsgreatly
exceededrechargeinmanyareas,causinglargewaterleveldeclines.Waterlevelshavedeclinedmore
than100feetsinceirrigationbegan(1940's)inpartsofKansas,NewMexico,Oklahoma,andTexas.In
someareas,becauseofwaterleveldeclines,irrigationhasbecomeimpossibleorcostprohibitive.”
Inresponsetothisbelief,theU.S.GeologicalSurvey,incooperationwithnumerousfederal,state,and
localwaterresourceagencies,beganagroundwatermonitoringprogramin1988toassessannual
waterlevelchangeintheaquiferusingwaterlevelmeasurementsfrommorethan7,000wells.
Changes in water level
measured during 1980 - 1999
The100”declineisactuallyonlyinsmalllocalizedregions.Forsome99%ofallwaterlevelchanges
between1980to1999,thedatashowarangefromariseof34feettoadeclineof67feet.Theaverage
areaweightedwaterlevelintheHighPlainsaquiferdeclined3.2feetfrom1980to1999comparedtoa
declineof9.9feetfrompredevelopmentto1980.Intheareaswithfrom50to175feetofwaterlevel
declinefrompredevelopmentto1980,theaveragewaterleveldeclinefrom1980to1999was26feetor
about1.4feetperyear.Thisdoesnotequatetotheheadlinesofa100’lossofwateracrosstheaquifer.
Themostrecentdataavailableshowsthechangefrompredevelopmentto2005asfollows:
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Changes in water level
measured during from
Predevelopment to 2005
Totalwaterinstorageintheaquiferin2005wasabout2,925millionacrefeet,whichwasadeclineof
about253millionacrefeet(or9percent)sincepredevelopment.Comparingthedatainthetwocharts
aboveitseemsthat:
1. Thedeclineinwaterlevelintheaquiferdoesnotcorrespondtothehighestnumberofcorn
irrigatedacres.Infact,inNebraska,theaquiferwaterlevelseemstoberising.
2. Thedatafor2005seemstoshowmoreintensewaterlevelchangesinlocalizedareasbutnot
acrosstheaquifer.Whydoeswaternotflowwithintheaquifer?
4.FutureNeeds&Issues
Moretimelyinformationandavailabilityofcurrentdataisimportant.Atpresent,thedatabeingusedis
possiblynolongerrelevant,orisnotaclearcurrentpicture.Forexample,theUSDAagricultural
irrigationdataareallfromthe1990’sorbefore.TheUSGSusesolddatawithafewreferencestoearly
2000’sdata,thesurveyof2005isnotyetpublished.Manyofthedebatesarebasedonolddataandthe
presenttrendisunclear.Forexample,inrecentyearsthenumberofacresirrigatedhasdeclined,orthe
numberofacresirrigatedhasremainedflatwhilethevolumeofwaterutilizedhasdeclineddueto
newermanagementtechniquesandbetterequipment–butthesefactorsareseldombroughtforthin
thedebate.
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Cornisarelativelysmallintermsofirrigation.AcrosstheUS,theacresofcornirrigatedrepresent21%
ofthetotalirrigatedarea.However,thevolumeofwaterutilizedincornirrigationrepresentsonly7%of
allirrigationwater.Moreover,theprimaryareaforcornirrigationliesovertheHighPlainsaquiferwhich
doesnotcorrespondtothemostintensewaterutilizationforirrigation(seefollowingchart):
Clearly,Californiaiswherethemainissueexistsinrelationtowateravailabilityforirrigation.ForCAand
otherlocalizedareas,someactionplanisrequiredtodealwithfutureneeds.Historically,increased
waterdemandsweremetbyexpandingavailablewatersupplies.Actionssuchasdamconstruction,
moregroundwaterpumping,andinterbasinconveyancearenotlikelytocontinueonanysignificant
scale.Thereareseveralschoolsofthoughtthatevensuggestthefuturesupplyoffreshwater(via
precipitation)willbedecreasedduetoconceptsaboutglobalwarming.Whilewecanfindevidencethat
somewarminghasoccurredinurbansituations,wedon’tfindanysignificantwarmingintheMidWest,
noranyrelationshiptorainfallpatterns,overthepast100years.Forexample,thefollowingchartsare
justtwoexamplestations:
Rainfall
Temperature
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Page26of34
Rainfall
Temperature
Futurewaterdemandswillrequireoneormoreofthefollowingsolutions:
x
x
x
x
x
x
Reallocationofexistingsupplies:willlikelyimpactagriculturewithwaterbeingtakenforpublic
utilization,overirrigation.
Changeincropwaterneed.Weseethisasbeingverydifficultsinceloweringtranspirationhasa
biologicallimitduetotheneedtocooltheplant.Droughttolerancegenesmayhelptosome
extentbuttheirmodeofactionislikelytoberelatedtoturgorpressureratherthanloweringthe
transpiration:yieldratio.Droughttolerancewillincreaseyieldinsomesituations,suchasminor
waterstress,butwillnotovercomemajorwaterdeficit.
Continuationofimprovementinwaterdelivery.Irrigationmanagement,efficiencyofwater
delivery,betterequipmentwillallmakeacontribution.
Recyclingmorewaterviaadvancedtreatmentsandreverseosmosis.Allindustrial,processand
livestockwaterusecouldbefurtherrecycled–oftenwithinagriculture.
Generatingmorefreshwatersupplywillneedtobeconsideredveryseriously,especiallyin
California.Areasinproximitytotheseathatrequireadditionalwatercanusedesalinationwith
shortandmediumdistancetransportinspecificpipelines.Thisisjustmovingwaterfromthe
largestsourcetoanareathatrequiresmorewaterforutilizationbyallthehumanactivities.
Inthelongerterm,theremayevenbeaneedtorunapipelinefromseasidedesalinationplants
torechargethecentralaquifersystem.Thereisnorealshortageofwaterintheworld–justin
somelocationsandthetechnologyexiststofixthat.
Itisagrowingfashiontotalkabouttheworldshortageofwater–whichisastrangestatementwhen
theplanetis70%coveredwithawatervolumeinexcessof330millioncubicmiles.Thecurrentsituation
ismoreaboutcostthanitisaboutwater.Itreallybecomesaquestionofwhatvaluesocietyputson
havingwateravailabletofacilitateprocessingandtheprovisionofusefulproducts.Giventhepricethat
peoplepayforbottledwater(anotherformofredistribution)itseemsthatpipelinedeliveryof
desalinatedwatershouldbequiteacceptable.
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5.References
Connor,R.,Faurès,JM.,Kuylenstierna,J.,Margat,J.,Steduto,P.,Vallée,D.,andvanderHoek,W.
(2009).Chapter7:EvolutionofWaterUse.In,WaterinaChangingWorld.3rdU.N.WorldWater
DevelopmentReport.UnitedNationsEducational,ScientificandCulturalOrganization(UNESCO)Natural
Sciences,Paris,France.
Gleick, P. H., (1996). Water resources. In Encyclopedia of Climate and Weather, Ed. Schneider,
S.H., Oxford University Press, New York, pp.817-823.
Hoekstra,A.Y.,andChapagain,A.K.(2007).WaterFootprintsofNations:Waterusebypeopleasa
functionoftheirconsumptionpattern.WaterResourcesManagement,21,3548.
NCDC(2009).NationalClimaticDataCenter,NOAASatelliteandInformationService.
http://www.ncdc.noaa.gov/oa/ncdc.html
NebGuide(1996).Evapotranspiration(ET)orCropWaterUse.UniversityofNebraska,Cooperative
ExtensionInstituteofAgricultureandNaturalResources,NebGuideG90992A
Reilly,T.E.,Dennehy,K.F.,Alley,W.M.,andCunningham,W.L.(2008).GroundWaterAvailabilityinthe
UnitedStates:U.S.GeologicalSurveyCircular1323,70pp.Denver,CO.
USDA(2004).FarmandRanchIrrigationSurvey(2003).Volume3,Part1,SpecialStudiesof2002Census
ofAgriculture,AC02SS1.U.S.DepartmentofAgriculture,NationalAgriculturalStatisticsService.
USGS(2006).WaterLevelChangesintheHighPlainsAquifer,Predevelopmentto2005and2003to
2005.ScientificInvestigationsReport2006–5324.
USGS(2009).UnitedStatesGeologicalSurvey.http://www.usgs.gov
USGS(2009B).USGSreportsonestimatedwateruseintheU.S.http://water.usgs.gov/watuse/
WW2010(2009).WeatherWorld2010ProjectattheUniversityofIllinois.
http://ww2010.atmos.uiuc.edu/(Gh)/home.rxml
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Page28of34
APPENDIX
Oneestimateofglobalwaterdistribution:
Watersource
Watervolume,in
cubicmiles
Watervolume,in
cubickilometers
Percentof
freshwater
Percentof
totalwater
Oceans,Seas,&Bays
321,000,000
1,338,000,000
96.5
Icecaps,Glaciers,&
PermanentSnow
5,773,000
24,064,000
68.7
1.74
Groundwater
5,614,000
23,400,000
1.7
Fresh
2,526,000
10,530,000
30.1
0.76
Saline
3,088,000
12,870,000
0.94
SoilMoisture
3,959
16,500
0.05
0.001
GroundIce&
Permafrost
71,970
300,000
0.86
0.022
Lakes
42,320
176,400
0.013
Fresh
21,830
91,000
0.26
0.007
Saline
20,490
85,400
0.006
Atmosphere
3,095
12,900
0.04
0.001
SwampWater
2,752
11,470
0.03
0.0008
Rivers
509
2,120
0.006
0.0002
BiologicalWater
269
1,120
0.003
0.0001
332,500,000
1,386,000,000
100
Total
Source:Gleick,P.H.,1996:Waterresources.InEncyclopediaofClimateandWeather,ed.by
S.H.Schneider,OxfordUniversityPress,NewYork,vol.2,pp.817823.
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Totalwaterwithdrawalsbywaterusecategory,2000.(fromUSGS)
[Figuresmaynotsumtototalsbecauseofindependentrounding.Allvaluesareinmilliongallonsper
day.—,datanotcollected]
THERMOELECTRIC
PUBLIC
LIVE AQUA
DOMESTICIRRIGATION
INDUSTRIAL MINING
POWER
SUPPLY
STOCKCULTURE
STATE
Fresh
Fresh
Fresh
Fresh Fresh Fresh SalineFreshSaline Fresh
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Districtof
Columbia
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
834
80.0
1,080
421
6,120
899
424
94.9
78.9
11.2
28.9
28.5
286
66.8
56.2
13.3
0
0
0.18
—
2,440
1,250
250
244
1,760
670
383
416
525
753
102
199
110
12.0
85.2
135
122
33.2
21.6
27.5
41.2
35.7
32.5
19.4
—
34.9
37.6
41.9
109
111
—
7.34
—
824
739
77.1
42.2
4,290
1,140
364
17,100
154
101
21.5
3,710
29.3
1,020
5.84
42.4
126
1,140
Minnesota
Mississippi
43.1
—
1.01
—
5,400
—
7,910
—
30,500 409
11,400
—
30.4
—
43.5 3.92
10.4
—
—
198
537
—
—
0.07
833
8.12
19.8
134
188
120
10.7
59.4
0
3.86
0
0.08
13.6
0
0
3.25
—
0
0
—
—
27.4 140
85.7 8.17
2.78
0
23.7 153
—
—
—
—
—
—
—
—
8.02 291 1.18 217
15.4 622 30.0 9.80
— 14.5 0.85 —
1,970 55.5
0 —
— 391
0 —
— 2,400
0 82.5
— 237
0 32.8
5.60 53.3
0 31.4
— 317
0 —
243 2,680
0 —
— 247
0 —
0
0
—
—
—
0
0
0
—
—
—
Saline Fresh Saline
8,190
0 9,990
0
33.6
0
161 144
100
0 6,720 8.17
2,180
0 10,900 0.08
352 12,600 38,40012,800
138
0 12,600
0
187 3,440
708 3,440
366
738
582 741
658 12,000 8,14012,000
3,250
61.7 6,410 91.7
0
0
640 0.85
0
0 19,500
0
11,300
0 13,700
0
6,700
0 10,100
0
2,540
0 3,360
0
2,260
0 6,610
0
3,260
0 4,160
0
5,610
0 10,400
0
113
295
504 295
20,100
6,500
641
19,500
13,700
10,100
3,360
6,610
4,160
10,400
799
19.6
—
239
201 11.3
—
698
0
—
—
7,710
500
359
80.8
69.3
227 52.8
1,410
—
—
371
154
242
0 588
0 —
0
—
2,270
362
0
148
Missouri
872
53.6
1,430 72.4
83.3
62.7
0 16.9
0
5,640
0
Montana
Nebraska
149
330
18.6
48.4
7,950
—
8,790 93.4
—
—
61.3
38.1
0 —
—
0 128 4.55
110
2,820
Nevada
629
New
97.1
Hampshire
NewJersey
1,050
NewMexico
296
NewYork
2,570
NorthCarolina 945
22.4
2,110
—
—
10.3
0
—
—
36.7
0
41.0
4.75
—
16.3
44.9
0 6.80
0
236
761
140 1.68
2,860
—
35.5
—
287 121
6.46
—
—
7.88
132
10.5
297
293
0 110
0 —
0 —
0 36.4
0
—
—
0
650
56.4
4,040
7,850
3,390
0
5,010
1,620
NorthDakota
63.6
11.9
145
—
—
17.6
0
—
—
902
0
1,470
134
31.7 25.3
1.36
807
0 88.5
0
8,590
Ohio
ByStrathKirnInc.
79.7
31.4
142
189
65.8 227 8.31 0.02
36.8
0 —
—
9,990
305
6,730
10,900
51,200
12,600
4,150
1,320
9.87
379
108
0
6,260
3,610
9.87
Total
0
9.69
10.4
—
Michigan
TOTAL
1,430 6,490
1,050 3,610
0 10,000
7,910
4,660
0
10,000
3,870
2,810
0
148
3,870
2,960
8,230
0
8,230
0 8,290
0 12,200
0
4.55
8,290
12,300
2,810
0
2,810
447
761
1,210
2,170 3,390
3,260
0
7,080 5,010
9,730 1,620
5,560
3,260
12,100
11,400
1,140
0
1,140
0 11,100
0
11,100
Page30of34
Oklahoma
Oregon
675
25.5
718 151
16.4
25.9
195
0 2.48 256
0
1,760
256
2,020
566
76.2
6,080
—
—
—
—
15.30
0
6,930
0
6,930
Pennsylvania
1,460
132
13.9
—
— 1,190
0 182
0
6,980
0
9,950
0
9,950
RhodeIsland
119
8.99
3.45
—
—
4.28
0
—
—
2.40
290
138
290
429
SouthCarolina
566
63.5
267
—
—
565
0
—
—
5,710
0
7,170
0
7,170
SouthDakota
Tennessee
93.3
890
9.53
32.6
373 42.0
22.4
—
—
—
5.12
842
0
0
—
—
—
—
5.24
9,040
0
528
0 10,800
0
0
528
10,800
4,230
131
8,630 308
— 1,450 907 220 504
9,820
3,440 24,800 4,850
29,600
Utah
Vermont
638
60.1
16.1
21.0
3,860
3.78
—
—
116
—
Virginia
720
133
26.4
—
1,020
125
3,040
WestVirginia
190
40.4
0.04
Wisconsin
623
96.3
Wyoming
107
6.57
4,500
PuertoRico
513
0.88
U.S.Virgin
Islands
6.09
1.69
43,300
3,590
Texas
Washington
TOTAL
0
146
42.7 5.08 26.3 198
6.91
0 —
—
62.20
355
0
0
—
470 53.3
—
—
3,850
3,580
—
—
577 39.9
—
—
519
—
—
968
0
—
—
196 66.3
70.2
447
0
—
—
—
94.5
—
0.50
—
137,000 1,760
4,760
447
203
0
4,970
447
5,200 3,640
8,830
0
5,270
39.9
5,310
3,950
0
5,150
0
5,150
—
6,090
0
7,590
0
7,590
5.78
0 79.5 222
243
0
4,940
222
5,170
—
11.2
0
—
—
0
2,190
620 2,190
2,810
—
3.34
0
—
—
0
136
11.6
136
148
3,70018,500 1,2802,010 1,490 136,000 59,500345,00062,300
408,000
ByStrathKirnInc.
Page31of34
TrendsinestimatedwateruseintheUnitedStates,19502000.(USGS,2009B)
Thewaterusedataareinbilliongallonsperday(thousandmilliongallonsperday)andareroundedto
twosignificantfiguresfor195080,andtothreesignificantfiguresfor19852000;percentagechangeis
calculatedfromunroundednumbers.—,notavailable]
Year
Percentage
change
195021955319604196541970319753198031985319903199532000
19952000
1
Population,inmillions
150.7164.0179.3193.8205.9216.4229.6242.4252.3267.1285.3
Offstreamuse:
Totalwithdrawals
180 240 270 310 370 420 440 399 408 402 408
Publicsupply
14 17 21 24 27 29 34 36.5 38.5 40.2 43.3
Ruraldomesticandlivestock:
Selfsupplieddomestic
2.1 2.1 2.0 2.3 2.6 2.8 3.4 3.32 3.39 3.39 3.59
Livestockandaquaculture 1.5 1.5 1.6 1.7 1.9 2.1 2.2 54.47 4.50 5.49 (6)
Irrigation
89 110 110 120 130 140 150 137 137 134 137
Industrial:
Thermoelectricpoweruse 40 72 100 130 170 200 210 187 195 190 195
Otherindustrialuse
37 39 38 46 47 45 45 30.5 29.9 29.1 (7)
Sourceofwater:
Ground:
Fresh
34 47 50 60 68 82 83 73.2 79.4 76.4 83.3
Saline
(8) 0.6 0.4 0.5 1.0 1.0 0.9 0.65 1.22 1.11 1.26
Surface:
Fresh
140 180 190 210 250 260 290 265 259 264 262
Saline
10 18 31 43 53 69 71 59.6 68.2 59.7 61
+7
+2
+8
+6
—
+2
+3
—
+9
+14
1
+2
1
48StatesandDistrictofColumbia,andHawaii
48StatesandDistrictofColumbia
3
50StatesandDistrictofColumbia,PuertoRico,andU.S.VirginIslands
4
50StatesandDistrictofColumbia,andPuertoRico
5
From1985topresentthiscategoryincludeswateruseforfishfarms
6
Datanotavailableforallstates;partialtotalwas5.46
7
Commercialusenotavailable;industrialandminingusetotaled23.2
8
Datanotavailable
2
ByStrathKirnInc.
Page32of34
IrrigationdatafromUSGSSurveyin2000(USGS,2009B)
APPLICAT
ION
IRRIGATED LAND
WITHDRAWAL S
WITHDRAWALS
(in thousand acres)
(in million gallons per day)
(in thousand acre-feet per y ear)
RATE
(in acrefeet
per acre)
STATE
By type of irrigation
By source
By source
Total
Sprinkle
Micro-
Total
Surface
irrigatn
Ground
Surface
water
water
Total
Ground
Surface
water
water
Alabama
68.7
1.3
0
70
14.5
28.7
43.1
16.2
32.2
48.4
Alaska
2.43
0
0.07
2.5
0.99
0.02
1.01
1.11
0.02
1.13
0.69
0.45
Arizona
183
14
779
976
2,750
2,660
5,400
3,080
2,980
6,060
6.21
Arkansas
631
0
3,880
4,510
6,510
1,410
7,910
7,290
1,580
8,870
1.97
California
1,660
3,010
5,470
10,100
11,600
18,900
30,500
13,100
21,100
34,200
3.37
Colorado
1,190
1.16
2,220
3,400
2,160
9,260
11,400
2,420
10,400
12,800
3.76
Connecticut
20.6
0.39
0
21
17
13.4
30.4
19
15
34
1.62
Delaware
81.1
0.71
0
81.8
35.6
7.89
43.5
39.9
8.84
48.7
0.6
DC
0.32
0
0
0.32
0
0.18
0.18
0
0.2
0.2
0.63
515
704
839
2,060
2,180
2,110
4,290
2,450
2,370
4,810
2.34
1,470
73.8
0
1,540
750
392
1,140
841
439
1,280
0.83
16.7
105
0
122
171
193
364
191
216
407
3.35
Florida
Georgia
Hawaii
2,440
4.7
1,300
3,750
3,720
13,300
17,100
4,170
15,000
19,100
5.1
Illinois
365
0
0
365
150
4.25
154
168
4.76
173
0.47
Indiana
250
0
0
250
55.5
45.4
101
62.2
51
113
0.45
Idaho
Iowa
Kansas
84.5
0
0
84.5
20.4
1.08
21.5
22.9
1.21
24.1
0.28
2,660
2.14
647
3,310
3,430
288
3,710
3,840
323
4,160
1.26
0.49
Kentucky
66.6
0
0
66.6
1.14
28.2
29.3
1.28
31.6
32.9
Louisiana
110
0
830
940
791
232
1,020
887
261
1,150
1.22
35
0.95
0.03
36
0.61
5.23
5.84
0.68
5.86
6.55
0.18
0.78
Maine
Maryland
57.3
3.32
0
60.6
29.8
12.6
42.4
33.4
14.1
47.6
Massachusetts
26.6
2.35
0
29
19.7
106
126
22.1
119
141
4.88
Michigan
401
8.67
4.87
415
128
73.2
201
144
82
226
0.54
Minnesota
546
0
26.9
573
190
36.6
227
213
41.1
254
0.44
Mississippi
455
0
966
1,420
1,310
99.1
1,410
1,470
111
1,580
1.11
Missouri
532
1.43
792
1,330
1,380
48.1
1,430
1,550
53.9
1,600
1.21
Montana
506
0
1,220
1,720
83
7,870
7,950
93
8,820
8,920
5.18
4,110
0
3,710
7,820
7,420
1,370
8,790
8,320
1,540
9,860
1.26
192
0
456
647
567
1,540
2,110
635
1,730
2,360
3.65
6.08
0
0
6.08
0.5
4.25
4.75
0.56
4.76
5.32
0.88
Nebraska
Nevada
New Hampsh
New Jersey
109
15.7
3.7
128
22.8
117
140
25.5
131
156
1.22
New Mexico
461
7.17
530
998
1,230
1,630
2,860
1,380
1,830
3,210
3.22
70
8.73
1.84
80.6
23.3
12.1
35.5
26.1
13.6
39.8
0.49
North Carolina
193
3.7
0
196
65.8
221
287
73.8
248
322
1.64
North Dakota
200
0
26.7
227
72.2
73.2
145
80.9
82.1
163
0.72
0.58
New York
61
0
0
61
13.9
17.8
31.7
15.6
19.9
35.5
392
1.5
113
507
566
151
718
635
170
804
1.59
1,160
4.02
1,000
2,170
792
5,290
6,080
887
5,920
6,810
3.14
Pennsylvania
28.9
7.17
0
36
1.38
12.5
13.9
1.55
14
15.6
0. 43
Rhode Island
4.48
0.29
0.05
4.82
0.46
2.99
3.45
0.52
3.35
3.87
0.8
Ohio
Oklahoma
Oregon
ByStrathKirnInc.
Page33of34
Continued…
IRRIGATED LAND
WITHDRAWAL S
WITHDRAWALS
(in thousand acres)
(in million gallons per day)
(in thousand acre-feet per y ear)
APPLICAT
ION
RATE
(in acrefeet
per acre)
STATE
By type of irrigation
By source
By source
Total
Sprinkle
Micro-
Surface
irrigatn
Total
Total
Ground
Surface
Ground
Surface
water
water
water
water
South Carolina
166
3.66
17.5
187
106
162
267
118
181
300
1.6
South Dakota
276
0
78.3
354
137
236
373
153
264
418
1.18
0.41
51.2
5.35
3.96
60.5
7.33
15.1
22.4
8.22
16.9
25.1
4,010
89.4
2,390
6,490
6,500
2,130
8,630
7,290
2,390
9,680
1.49
526
1.68
880
1,410
469
3,390
3,860
526
3,800
4,330
3.08
Tennessee
Texas
Utah
Vermont
4.95
0
0
4.95
0.33
3.45
3.78
0.37
3.87
4.24
0.86
Virginia
64.3
13.9
0
78.2
3.57
22.8
26.4
4
25.6
29.6
0.38
1,270
49.9
252
1,570
747
2,290
3,040
837
2,570
3,400
2.16
2.21
0
0.98
3.19
0.02
0.02
0.04
0.02
0.02
0.04
0. 01
355
0
0
355
195
1.57
196
218
1.76
220
0.62
Washington
West Virginia
Wisconsin
Wyoming
190
4.73
964
1,160
413
4,090
4,500
463
4,580
5,050
4.36
15.5
33
5.35
53.8
36.9
57.5
94.5
41.4
64.5
106
1.97
0.2
0
0
0.2
0.29
0.21
0.5
0.33
0.24
0.56
2.8
28,300
4,180
29,400
61,900
56,900
80,000
137,000
63,800
89,700
153,000
2.48
Puerto Rico
U.S. Virgin Isl
TOTAL
Note:Irrigationunits
Gallonsisavolumeapplied.Acresistheareathatavolumeisappliedto.Oneacrefootisthevolumeof
waterthatcoversoneacretoadepthofonefoot:equals43,560cubicfeet=325,851gallons.Oneacre
inch=27,154gal.
ByStrathKirnInc.
Page34of34
NCGA National Office
$FQJ%SJWF
$IFTUFSöFME .0 'BY
NCGA Washington Office
$ 4USFFU /8
4VJUF
8BTIJOHUPO%$
'BY
June 2009 © National Corn Growers Association