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INTRODUCTION AND SUMMARY

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INTRODUCTION

History of the census of irrigation.-Inquiries relating to irri- gation have been inclurled in each decennial census of agriculture since 1890. A .•mecial een.~us vertaining to irrigation was taken in 1!}02. Inquiries relating to the acreage irrigated in each farm were includecl in the mid-decennial eensuses of agriculture in 1935 ancl 194fi. Beginning in 1910, a special census of irrigation in the States in whkh irrig11tion Is most extensive has been taken in addition to the decennial census of agriculture. In this special census of irrigation, clata arc~ obtained from irrigation enterprises, i. e., the irrigation companies, districts, and other irrigation organi- zations, and from farms that operate their own indlvicltml irriga- tion supply works. The States incluclecl in the census in 1910,

1920, and rnao were the 17 Western States and Arkansas and

LouiRiana. In Hl40 and lfl50, Florida also was included. Legal basis for the 1950 Census of Irrigation.-Authorlzation for the 1950 Censuk· of Irrigation was made in an act of Congress approvecl June 18, ln29, providing for the flftee-nth and subsequent decennial censuses. Questionnaires used.-Two irrigation questionnaires, desif.,"" nated I-1 and I-2, were used. The I-1 questionnaire was used for enumeration of irrigation Pnterprises operated by farms indi- vidually, and the I-2 for the irrigation companies, districts, and other enterprises not operated by farms individually. On the irrigation questionnaires, inquiries were included as to type of enterprise; irrigation supply wo1·ks and' equipment; pumD- ing lift of pumped wells; sources of irrigation water; pumping of water; storage of water; whether water was obtained from or delivered to other enterprises; new capital investment between January 1, 11)40, and December 31, 1940; number of farms and the acreage irrigated ; acreage of irrigated lane! artificially drained aml acreage in need of d:i:ainage; cost of water to farms; and season of irrigation. I•'or the irrigation companies, districts, and other irrigation organizations (but not for irrigation enterprises operated by Individual farms), additional inquiries were included as to whether the enterprise was n multipurpose enterprise; indebtedness of tile enterprise; arrearage in payment of indebted- ness; arrearage of water userH in payments to the enterprise; amount of payment for water for purposes other than operation and maintenance; measurement of wuter delivered to farms; and qnantitie:;; of water obtainecl, lost in conveyance, and delivered to farms. The inquiries included iu the irrigution questionnuires and the wording of the inquiries were determined with the assistance of an irrigntion adYisory committee and on the basis of experience gainecl in two pretests of tentative questionnaires. The advisory committee consisted of representntives of the Bureau of Reclama- tion and the Bureau of Indian Affairs of the 'Department of Interior; and of the Bureau of Agricultural FJconomics, the Soil Conservation Sei·vice, an<l the Bureau of Plant Industry, Soils, and Agricultural Engineering of the De1)artment of Agriculture. A pretest of the tentatiYe questionnuires was made in areus in C:o!orado and Idaho in October 19,!8. The questionnaires were then revised and were again pretested in several areas in the Western States in May 1949. Irrigation data from the 1950 Census of Agrioulture.-Inqniries were included in ·the 1950 Census of Agriculture questionnaire for each of the 48 States as to acreage of irrigatecl land and acreage irrigated by meitnH of sprinklerH. For the ~'ltntes in whil'h tlw

ipecinl censnH of irrigation was taken (the 17 We:;;tei·n Rtates and Arkansas, Louisiana, and Inorida), additional inquiries were included on the questionnaire for the census of agriculture as to tile major uses of the irrigated land, acreages of individual crops that were irrigated, acreages irrigated with tile water from each irrigation enterprise from which the farm obtained water, and the names of irrigation companies, districts, or other organir.ed enterprises from which water was obtained. The enumeration.-Enumeration of the larger irrigation enter- prises (those supplying water to 10 or more farms), was accom- plishecl dlll'in~ .Jnlrnar~', February, and March, 1950. Lists of these enterprises were com11iled from the reports of the 1940 Census of Irrigation. In most cases, copies of the irrigation questionnaire WPre mai!Pd to irrigation enterprises a short time before the enumerator plunned to visit them, in order to enable offieials of the entervrises to have necessary data available and to fill out the questimmnirP if they so desired'. 'l'hese lnrger entervrises were enumerated by specially qualified irrigation technicians. Most of these technicians were profes· sional employees of the Soil Conservation Service of the United Stntes Department of Agriculture, who were familiar with irriga- tion t•orHlitions and practices in the areas in which they worked, and who were detailed to the Bureau of the Census to assist in taking the census of irrigation. Their special knowledge and ability contrilrntecl matPrially to the obtaining of reliable infor- mation for the larger· irrigation enterprises, which supply water for more than one-half of the irrigateff Janel in the United States. 'l'he irrigation enterprises operatecl by farms indlvi<lually were en umernted at the same time that the other census information for farms wus ohtainecl, by regular census enumerators who re- c:eivPd special training in the use of the I-1 questionnaire. This enumeration was eompletecl during April and early lVr'ay 1950. 'l'he names of irrigation enterr>rises from which the furms obtained irrigation water during 11)49 were reported on the agr!- c:nlture quc:>stionnaire. In eueh census superviR01"s office a list was kept of the irrigation enterprises, other than single-farm e11t:Pr1n•iseH, that had Ileen enumerated in January, Febl'uary, and l\larch. Another lii;t was kept of all ente .. ·prises which were listeci on agriculture queHtionnaires, but which hacl not been ennmeratecl in the irrigation census. These were chiefly enter- prise:;; thn 1 HllP!lliecl water for from two to nine fnrms. 'l'he8e en tl'l'p1·ises were enumerated by special irrigation enumerators, trained and supervisecl by the irrigation technicians. By means of this woeeclure, practically complete coverage of irrigution t>nterprises was secured. For each irrigation m1ter11rise reported on the questionnaires for the cenHus of agriculture, n listing was made of the farms thnt reportetl acreage irrigated with water obtained from the entel'}>riHe. When the farm enumerntion in the urea served by the enterin'iHe was comple-ted, the irrigated acreages reporte<l on the agriculture questionnaire were totaled and compared with the acreage irrigatecl as reported on the irrigation questionnaire for the enterprise. In cases of a clift'erenC'e of 10 percent or more, the irrigation technicians inv~stigated the reasons for the differenee. ErrorA in reporting on tlle questionnaires, disclosed h~y these investigations, were tht'n cor1·ected, By this procedure, most of the overestimation of Irrigated acreage by the enterprises, undPr-rP1101·tlng of Irrigated atrengP for inclivirlnnl farmR, ancl

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INTRODUCTION 3

in the census of irrigation, the land was usually tabulated in the county in which it was located. Data obtained for United States Bureau of B.eclamation proj- ects, which supplied all or part of the water for nearly 20 percent of the total irrigated acr~age in the 17 Western States, were checked for aceuracy by representatiYes of the Washington Qffice of the Bureau of Reclamation. The reports for the larger storage reservoirs were compared with those in published lists of water-storage reservoirs In the United States in order to insure completeness and accuracy. Information for all items appears to have been completely re- ported, with the exception of pumping lift of pumped wells and season of irrigation, on both the I-1 and I-2 questionnaires, anrl of measurement of water and quantities of water on the 1- questionnaire. The data shown for pumping lift, season of ir- rigation, measurement of water, and quantities of water are for only the enterprises that reported, not for all enterprises. Comparability with prior censuses.-The 1950 Census of Irri- gation shows a decrease of about 9 percent ln irrigated land in Colorado, and small decreases in Idaho, Nevada, Utah, and Wyoming, as compared with 1940. This decrease was not actual,

because it is the result of differences ill the method of processing

the questionnaires for the 1950 and the 1940 censuses: Over- estimation and duplication of ir1igated acreage were more fully eliminated during oftlce processing in the 1950 than In the 1940 census. If procedures similar to those used in lOl>O had been used in 1940, the 19'39 acreages shown for those States would have been less, and increases in acreage from 1939 to 1949, instead of decreases, would have been shown. The increases between 1940 and 1950 shown for other States would have been somewhat greater if the office nrocessing in 1940 had been the same as in

Lack of comparability of data from the 1950 census and simila1· data from prior censuses for certain other items is indicated in connection with the definitions and explanations of the items, or in the footnotes for the tables.

DEFINITIONS AND EXPLANATIONS

IRRIGATION DATA FROM THE 1950 CENSUS 0~' AGRIOULTUltE

Irrigated land Is land to which water is applied by artificial means for agricultural purposes. Only land actually irrigated in 1949 is included. Land in irrigated farms that was used for purposes such as roads and farmsteads, to which irrigation water was not applied, is excluded. Irrigated farms are farms in which 1 acre or more of land was irrigated in 1949. Places containing 3 or more acres that produced agrlctlltural products valued at $150 or more in 1949, and places containing less than. 3 acres with sales of agricultural products of $150 or more in 1949, are counted as farms.

Wholly irrigated farms are farms that reported 1 acre or more of cropland harvested in 19'49 and on which aii of the cropland harvested was irrigated. All, part, or none of the other land in the farm may have been irrigated.

Partly irrigated farms are all farms other than ··w.nolly irri- gated farms" with 1 acre or more of irrigated land In 1949.

Land irrigated by sprinklers is land to which 'water was applied, under pressure, from stationary or revolving sprinklers, or from perforated pipes, either overhead or on the surface of the ground, In 1!)49. Land for which sprinkler irrigation equipment was available, but which was not irrigated b~' sprinklers in 1949, is not included.

Irrigated wild grass pasture is·irrigated pasture consi'sting pre- dominantly of orig~nal stands of grasses native to the locality or re'established stands of such grasses.

Irrigated tame grass pasture is irrigated pasture consisting pre- dominantly of grasses not native or wild in the locality, and of alfalfa and clovers. Value of land and buildings.-In County Table 1 the average value of land and buildings per farm and per acre for all irri- gated farms and the average value of land and buildings per farm for wholly inigatef:l and for nonirrigated farms are shown. These average values are based on reports from a 20 percent sample of the farms plus reports from all farms classed as "large farm~." The value of land and buildings for irrigated farms In a county was computed by multiplying by 5 the values reported for sample farms that were irrigated, and adding to the amount thus ob· tained, the values reported for irrigated "large farms." The number 9f irrigated farms, and acreage of land represented by this figure, were computed in the same way. Similar calculntlons were made for· the value of land\and buildings for wholly irri- gated and for nonlrrlgated farms. The computed number of irrigated farms and acreage of land for which value of land and .buildings is reported may be more or less than the actual number of irrigated farms and the actual acreage of land, in irrigated farms. For example, if there were 100 irrigated farms in a county, but 21 of them were included in the sample for which value of land and buildings was reported, the computed number of irrigated farms for which value was reported would be 105, or 105 percent of the actual number of irrigated farms. For any county, the value of land and buildings based on the sample may differ considerably from the value that would have been secured if the value bad been obtained for all irrigated, wholly irrigated, or nonirrigated farll)s. The following tabula- tion may be used as a guide as to the reliability of the data for average value of land and buildings per acre and per farm for varying numbers of farms:

If t1ie total number of fariltB iB- 50 100 500 1, 5, 10, 50, 100,

T1ie c1ianoes are about 2 in 3 that t'/J,e estl- ma.tea value oJ land and buildi1ios would ditfer trom the 1·esults of a 001nplete ta.hula· tion for all farms bl/ less than- 35 ·percent 26 percent 11 percent 8 percent 7 percent 5 perc~nt _2 percent 1.5 percent

Other data from agriculture queationnaires.-For definitions and explanations of other terms used in connection with the data from the census of agriculture, see pages iX to XX of the Intro- duction to Volume I, Coun~les and State Economi~ Areas, United States Census of Agriculture, 1950.

1950 C1o:NSUl:I OF IRRIG4TION

J;rrigation enterprise.-An irrigation enterprise is a business, either private or public, that operates irrigation works to supply water for irrigation. Thus, an· individ'uo1 farm, a cooperative arrangement of two or more farmers, or a commercial company, irrigation district, or any other organization that operates irriga- tion supply works, ls an irrigation enterprise. Enterprises that delivered no water in '1949 because of water shortage or other reasons were included if they were going concerns that normally do deliver water for irrigation. New irrigation enterprises with construction of works not fully completed were included if water from the part of the works completed was delivered, or was availa.bl~ for delivery, for irrigation In 1949. Oom.plete system enterprises al;"e those that are practically in· dependent of .other enterprises in the obtaining and delivering of

4 IRRIGATION^ OF^ AGRICULTURAL^ LANDS

irrigation water. Enterprises that obtained from, or delivered to, other enterprises less than 10 percent of their water in 1949 are designated "complete system" enterprises. Acreage irrigated.-The acreage irrigated by an enterprise is the acreage of fm•m land irrigated in 1949 with water delivered directly to farms by the enterprise. It does not Include the 11creage irrigated with water which one enterprise delivered to another enterprise and which the other enterprise delivered to · farms. In "acreage irrigated direct," as used in this report, the acres of land that were irrigated with water clelivered directly to the farm by two ~r more different irrigation enterprises are counted for each enterprise. The total of "acreage irrigated rlirect" therefore JR scnnetimes greater than the total acreage of irrigated land. Acreage irrigated, like acree.g-e of irrigated land in the census of agricuiture, is the net acreage of farm land to which water was actually applied in 194B. It does not inc!urle land that could be irl'igated, or that usually ls irrigated, but was not ir- rigated during 1949. Land in irrigated farms used for purposes suC'h as roads and farmsteads, to which water wns not apvlied, Is excluded. Also excluded is irrigated land used for purposes other than farming, suC'l1 as Janel in rural rPsidential areas, cemeteries, parks, and golf courses. Acreage irrigated inclurles lard oil which water was applied to the 1rnrface of the ground and lanrl Oil which water was npplied beneath the surface by suhirrigation. Land floorlecl rluring hlgh- water pel'i9ds was clasi;ed as Irrigated only if water was purposely applied to the lanrl for agrkultura I purposes by clams, canals, or other works. Regulation of the "water table" of land by drain- age works was not eonsirlered as irrigation. Primary and supplemental irrigation.-In many cases land re- ceins irrigation water from two or more irrigation enterprises. The acreage of such land is counted as "acreage irrigated direct" for eac_h of the irrigation enterprises. To avoid counting this acreage more than once as irrigated Janel, it is designated "pri- mary'' irrigation for one of the enterprises and "supplemental" irrigation for the other enterprises. The· terms "primary" and "supplemental" are used only to distinguish hetween water su11- plied rlirectly to land by one irrigation enterprise and additional water supplied directly to the same land by other enterprise>:. Selection of the enterprise for which the water is designated as "primary" was entirely arbitrar,v and does not necesRHrily indicate the largest suppl~· of water or the earliest supply. Hence, af' used here, "supplemental" water does not mean water obtained by one irrigation enterprise from another irrigation enterprise to supplement its own supply-a rnther common usage of the term. Such water is referred to as "water obtained from other enterprises." Acreage of irrigated land is the aC'reage of land receiving pri- mar~· irrigation. Number of far.ms irrigated.-Places of 3 acres or more, anrl places of less than 3 acres that produced $Hl0 worth or more of farm products for sale in 1!H9 were considered as farms in pre- paring reports for the census of irrigation. Farms that received water from two or more irrigation enter· prises are counted for each enterprise in the census of irrigation. For most areas, therefore, the number of "farms irrigated clire<'t" exceeds the number of irrigated farms in the area. · Many irrigation enterprises have no record of number of farms irrigated, but.only of the number of parcels of lancl or the number of stockholders. In such cases, only estimates· of the number of farms were ohtained. These estirnateH sometimes were too l!igh becaui~e the numher of 11arcels of land or the number of stockholrlers mmally exceeds the number of farms, When in- formation obtained in the im·estigation of cliserepancies in ir- rigaterl acreage reported for the census of irrigation and for the eensus of agriculture indicated that the nulllher of farms reported as receh·lng water from an enterprise was more near!~· correct

than the number of farms estimated b~· t'he enterJll'ise, the former was substituted for the latter during the processing in the Washington office. For some States, particularly Arizona and New Mexico, the number of irrigated farms eounte<l for irrigation enterprises considerably exceeds the. number of il'l'igate1l farms eounted In the census of agriculture, largely because on the irrigation questionnaire the individual Indian allotments were reported as "farms" whereas in the census of agriculture the entire reser- vation, or an ndministrnti'e unit of a reservation, wns reported as a single farm. Type. of enterprise.-The types of enterprises under which rlata are classifier! are as follows: Single-farm enterprises are farms that individually operate irrigation supply works or equipment to obtain tlrnir own ir- rigation water. Single-farm enterprises may also su11ply water to one or more neighboring farms. Single-farm enterprises in the 1950 census are reasonably comparable with those designated "Indivirlual anrl partner- ship" In the 1940 census. Most of the enterprises designated "Partnei·shir1" in 1940 were classified "Unincorporated mutual" in 1950, but these comprised only a very small proportion of the total "Inc1ivirlual anrl partnership" group. For many counties, the number of single-farm enterprises does not 11gree with the total numher of farms reporting water obtained by means of their own individuall3· operated irrigation suppl)' works. Reasons for this difference are as follows : (1) In tlle census of agriculture, a farm extencling into two or more counties was counted only in the county in whieh its headquarters was located, but in the census of irrigation the single-farm irrigation enterprise was counter! in each c01inty in which any pllrt of its irrigation. works or irrigated land was located; (2) if a farm had irrigation supply works that were not usecl during 1949, tile works were reported as an irrigation entervrise but the farm was not reported as irrigated; (3) in some cases, tr.acts of Janel enumerated as separate farms were comhinecl as single farms during the office vrocessing for the census of agriculture, llut it was not feasible to make corre- sponding changes in the: census of irrigation; ( 4) in other eases, corrections we1'e made in the census of irrigation figures for errors in reporting how farms obtained irrigation water, but it was not feasible to make corresponding ehanges in the census of agriC'ulture; and (ii) irrigation questionnaires were not ohtainerl in some areas where only a fow farms reported small acreages of irrigated land. · Mutual, or cooperative, enterprises are those controlled and operated by two or more water users primarily to supply water to their own farms, with the exception of "District" enter- prises that are organizer! under special State laws. If 50 percent or more of the acreage irrigated was not in the farms of the water users that controller! and operated the enterprise, the enterprise was classified as ''commerrial." Mutual enter- prises include the operation of irrigation supply works or equipment .by two or more farms in "partnership"; by groups of water users informall~· assoeiatecl under verbal or written agreements; by mutual irrigation companies or water com- panies; by wnter-u,;er association~; by "lateral" companies; and by the community ditches or "acequias" in the Southwest that were organized originally in accordance with old Spanish, Mexican, or Indian customs. :Mutual enterprises may be either 1111!11co/'porated or ·incorvoratecl. Large intreases in number of unincorporated mutual enter- prif;es from 1!)40 to 1950 are shown for several States. These in<'reases resulterl more from the classification as "mutual" in l!l!'iO of enterprises that were classifiecl as "partnership" in 1040, and more nearly complete enumeration of small mutual enterprises in the 1950 census, than to the actual increase in number of unincorporated mutual enterprises during the decade. District enterprises are public corporations established unrler special State laws. Inclurlecl are irrigation districts, and also other ty11es of clistricts such as water-improvement, water- conservntion, nnd reclamation, which, in some States, are autl10rizerl in addition to irrigation districts, and In other States in lien of them. Reclamation cllstricts, organized under 8tate law;;, shoulcl not be confused with United States Bureau of Il.ecl11nmtion projectR, Commercial enterpriseH are prh·atel~· opernte<l enterprises (h~· inclivicluals, partnerships, or corporations) with more than r;o percent of the aerNtge irrigated in farms of water users that clo not share in the eontrol and operation of the enterprise. In somc c·a>:eH c·ommerc·ial enterprises are public utilities regulatec b~· a Rtate rommii;sion or hy the governing board of a county.

6 IRRIGATION^ OF^ AGRICULTURAL^ LANDS

or new improvements of irrigation works, or for acquiring water rights. It does not include expenditures for repairs or replace- ments, nor payments for works constructed prior to 1940. For works used for other purposes such as municipal water supply, hydroelectric power, or drainage in addition to use for irrigation, only the estimated part of the investment cost chargeable to irrigation is included. For new irrigation enterprises that were included in the census because they delivered irrigation water in i949 but that still had irrigation works under construction, the amount spent on both the completed and uncompleted parts of the works from .January 1, 1040, to December 31, 1949, was included. New capital investment for entervrises not yet in operation in 1949 was not included. Total capital investment in 1950 was comPutecl !Jy adding the "new capital Investment" to the total capital investment reported in the 1940 Census of Irrigation. In State Table 3, in which data by types of enterprises are presented, If an enterprise was a different type in 1050 from what it was in 1940, i. e., a "Com- mercial" enterprise reorganized as a "District,;' its capital in- vestment prior to 1940 is included in total capital investment for the type that the enterprise was in 11J40, ancl on!~· the "new capital investment" is included in total capital investment for the type that the enterprise was in 1950. Hence, for "District" and "Mutual" enterprises that in 1950 were operating irrigation works reported as Bureau of Reclamation enterprises in 1940, the capital investment for such works is included in State Table 3 in the total capital investment for Bureau of Reclamation enter- prises ancl not in t!lat for "District" or "Mutual." For inter.county ancl interdrainage basin enterprises in the 1950 census, the new capital investment was tabulated for the county or drainage basin in which the investment was made. In the 1940 census, total capital investment for such enterprises was allocated to the counties and drainage basins iii which the irrigated land was located. Hence, in some cases, when tlle lo- cation of the irrigation works and the location of Irrigated land was different, the figures for total capital ill'estment in 1950 b~· counties or by drainage basins are not comparable with the corresponding figure for total capital investment in 1940. In such cases, combinations shonlcl be made of. the figui·es to obtain data for a comparable area before comvarisons are made. The average new capital investment per acre of irrigated land is unusually high in some counties and drainage basins because land irrigatecl with \'ater from the woi·ks fill' which the new invest- 1nent was made \Yas lo('ated in othe.r counties or clrainap;e basins, or because all of the land eYentually to be irrigated was not irri- gated in 1949. Indebtedness.-Indebtedness represents the total indebtedness of an irrigation enterprise in outstanding bonds, notes, or balance payable on construction or purchase cost as of January 1, 1950. This item was not obtained for single-farm enterprises. ·Only indebtedness for expenditures made prior to January 1, 1950, is included. Indebtedness assumed in a few cases for works to be constructed after that date is not inclu~ecl. For enterprises that extended into two or more counties or drain- age basins, indebtedness was prorated among the counties or drainage basins proportionately to acreage irrigatecl direct, with the exception of two Bureau of Reclamation projects (the Colum- bia Basin project in Washington and the Central Yalley project in California) that were only partly completed at the time of the census. For the Columbia Basin project, indebtedness assumeil, or to he assumed, by the water users for i11Yestment as of January I, 1950, was divided proportionately to tl1e acreage of lands expected to .be irrigated. For the Central Valley project, such indebtedness was divided in the same wa~· 11s the ca1iital inmst- ment, because data on acreages to be irrigated were not arnilable, Arrearage on indebtednes.~ is the amount that the enterprise was in arrears In payment of principal or interest on indebtedness as of Januar~· 1, 1950. For intercounty and interdrainage basin

enterprises, this arrearage was prorated proportionate!~· to acre- age irrigated direct. This item was not obtained for single-farm enterprises. Arrearage in payments is the amount that the water users were

in arrears as of January i, 1950, for any payments owed by them

to an irrigation enterprise. This item was not obtained for single- farm enterprises. Irrigated land artificially drained.-Irrigated land artificially drained is the acreage of land Irrigated ln 1949 for which drain- age had been provided by artificial means, such us drainage ditches, tile, or pumped drainage wells. In the 1940 Irrigation Census, the acreage of all land for which artificial drainage had been provided· b~· an irrigation enterprise was reported as 1and artifically drained, instead of only the acreage of irrigated land tliat bad been drained. In this report, for counties in which the reported acreage of land drained in 1940 exceeded the acreage irrigated, the 1940 acreage of land drained has been reduced to equal the acreage Irrigated, in orcler to make the 1950 nnd 1940 acreages of land drained more nearly comparaNe. Corre- sponding acljnstments have been made in the drainage basin and State total figures for land drained. Irrigated land in need of drainage.-Irrignted land in need of drainage is the acreage of land irrigated in1949 that was reported aH needing artificial drainage, including 1and already artificially drained if it was in need of additional drainage. Adjustments in the 1940 acreages of land in need of drainage similar to those described above for the 1940 aereages of irrigated land artificall~· drained have .been made. Cost of water to farms.-For single-farm enterprises, cost of water to the farm or farms that received water ls the sum of the following four items that were reported for the year 1049: {1) Cost of electricity used for pumping for irrigntion; (2) cost

of fuel and oil trned for pumping for irrigation ; 01) cost of

repairs, maintenance, and replaeements for irrigation supply works and equipment (including the estimated value at prevailing wage rates of any work done by the farm operator in repair or maintenanee); and (4) payments made for water obtained from another irrigation enterprise and deliverecl to the land in the farm by menus of the irrigation supply works operated by the farm. For all enterprises other than single-farm entervrises, cost of water to farms is the amount of the payments fot irrigation water made by farms to the enterprises in 1949. Included are all kinds of payments such as as1iessments per aere or per Hhare of stock, water tolls, construction payments, bond and interest payments, and tmrments for operation and maintenance. If farmers per- formed maintenance or repair work on the irrigation works or equipment in lieu of payments to tile enterprise, the estimated rnlue of such work is included. In some cases, a farm obtains water from two or more enter- vrises but the water from all of the enterprises is delivered directly to the farm by only one of the ente111rises. In some of these cases, all payments for the water are made to the enterprise that delivers the water directly; in others, .the farm makes sepa- rate vayments to each of the enterprises involYed. In tl1e census of irrigation, all payments for water delivered directl~" to farms b~· an enterprise were reported on the questionnaire for that enteri1rise, including any parments macle by farms to otller enterprises that supplied water to the enterprise making the deJiyery direct. This procedure minimized the possibility of duplication in revorting payments for water. "Cost of water to farms" t11us represents the total cost to the farms for the water whjeh an enterprise cleliYered directly to the farms, and does not include payments that an enterprise may have received directly or indirectly for water which it delivered to other enter- prises. Hence, no cost of water to farms is reported for enter- vrlses that delivered all of their water to other enterprises, with the exception of a few "W!lter-spreading" or ground-water re-

INTRODUCTION 7

plenishment enterprises. (These enterprises put water into the ground, and it is then pumped by all of the enterprises in the area served.) Payment for the water in the case of ground~water replenishment enterprises is obtained by a tax levied on all of the irrigated land that is benefited. Because it.was impracticable, in these cases, to apportion the cost of the water to all the enterprises involved, the total amount of the tax collected in 1949 was reported as "cost of water to farms" on the questionnaires of the "water-spreading" enterprises even though no land was irrigated direct. For some areas with a small number of enterprises, unusually high repair expense incurred by one or more single-farm enter- prises resulted in abnormally high cost of water for the area. Many single-farm enterprises with gravity diversions from streams, especially those where the diversion was from a stream on the farm, reported no maintenance or repair work for 1949 and therefore had no cost for obtaining irrigation water. Payments other than for operation and maintenance is that part of the total payments for water for purposes such as con- struction or purchase cost, bonds and interest, or sinking fund. This item was not obtained for single-farm enterprises. In 1949, payments for purposes other than operation and main- tenance were unusually high for some enterprises, .because the enterprises took advantage of the unusually good income of farmers to collect larger than usual payments for the purpose of reducing Indebtedness or making improvements. Measurement of water to farms.-Measurement of water to farms means the use of any measuring device such as a weir, or meter, or calibration of a pump, to measure the water delivered to each individual farm. Quantity of water.-Quantities of water are reported in the tables in acre-feet. An acre-foot is the quantity sufficient to cover 1 acre to a depth of 1 foot, or 43,560 cubic feet. Quantities of water reported on the questionnaires in units other than acre- feet were converted to acre-feet. Quantities of water obtained

235115 n - 53 - 2

and used were not reported by single-farm enterprises. For enterprises that operated storage reservoirs, the quantity of water obtained represents the quantities withdrawn from and not the quantities diverted into, reservoirs in 1949. A calculated average quantity of water per acre for the total irrigated land, primary and supplemental irrigation combined, is given in County Table 2 and in Drainage Basin Table 1. This figure was calculated by multiplying the total acres of primary irrigation lllld of supplemental irrigation by the average quantities of water ver acre reported for each (by· the enterprises that reported quantity of water) and dividing the total quantity of water thus calculated for all irrigated land by the total acres of irrigated land. Drainage basin.-A drainage basin is the area of land from which water flows into a given stream, lake, or other body of water, or into a natural depression. Drainage basins from which water does not flow into streams that lead to the ocean are termed "Independent basins." With a few exceptions, the data have been tabulated sepa- rately in the 1950 census only fo1· drainage basins in which 5, acres or more of irrigated land was reported for 1949, thus eliminating a number of drainage basins with smaller acreages of irrigated land, shown for the 1940 census. However, a number of basins with large acreages shown as single basins in the 1940 census have been subdivided into two or more basins for the 1950 census. A number of changes were made for 1950 in the drainage basin boundaries 'used in 1940, in order to conform more closely with drainage basin boundaries used by other Government agencies and with stream-gaging stations. Acreages Of irrigated land within the revised drainage basin boundaries were estimated for 1940 from the 1940 maps showing location of irrigated land. These estimated figures are given in Drainage Basin Table 1. Revised 1940 data for other items are not available for the basins with changed boundaries.

SUMMARY (^9)

For the years Hl29 and 1939, the large differences between the acreages reported in the census of irrigation and in the census of agriculture may be explained by: (1) The overestimation and duplication of irrigated acreage as reported for irrigation enter- prises; (2) the under-reporting of irrigated acreage in farms; and (3) the limitation of the acreage reported for the HJ40 Census of Agriculture to irrigated cropland harvested plus irrigated pasture, and for the HJ:30 Ceirnus of Agriculture, to irrigated cropland harvested. The acreage for the 1935 Census of Agri- culture was limited to irrigated crops and the acreage may have been incompletely reported. The irrigated land in farms as reported for the 1950 Census of Agriculture was distributed as follows: In the 17 Western States, 9<1.1 percent; in Arkansas and Louisiana, 3.D percent; in Florida, 1.4 percent; and in the other 28 States, 0.(j percent. California had the largest area, with 6.4 million acres, or 25 percent of the total for the United States; Texas was second with 3.1 million acres; and Colorado, third with 2.9 million acres. Among the 28 States other than the 17 Western States and Arkansas, Louisiana, and Florida, New Jersey was first, with 28,117 acres; New Yo~·k, second, with 19,248 acres; and Massa-· chusetts, third, with 18,507 acres. The 25.8 million acres of irrigated land in farms in the United States reported for the 1950 Census of Agriculture was an increase of 43 percent over the 18.0 million acres of irrigated cropland harvested pl us irrigated pasture reported for the 1940 Census. Increases were reported for every State except Iowa, Nevada, and West Virginia. The largest increase, from 0.9 to 3.1 million acres, was in Texas; the second largest, from 4.3 to 6.4 million acres, was in California; and the third largeHt, from 2.5 to 2. million acres, was in Colorado. Excluding States in which less than 1,000 acres of irrigated land were reported for HJ39, the largest

ACREAGE OF IRRIGATED LAND IN THE UNITED STATES: 1889 TO 1949 MILLIONS OF ACRES 30

25

20

15

10

5

0

iI /

i /;/

I /

~------+ (^) / CENSUS~:/ (^) I1/' I

~-t /.

I

SPECIAL CENSUS y OF 1902-,

rr-----^

AGRICULTURE 0

~~

.CENSUS OF ,...,..

l; ,,.·

' (^1889 1899 1909 1919 1929 1934 1939 1944 ) J/ TOTAL IRRIGATED LAND IN FARMS. FOR 1909, 1919·, ANO 192.9, IRRIGATION CENSUS INCLUDED THE 17 WESTERN STATES ANO ARKANSAS ANO LOUISIANA; FOR 1939 AND 1949, FLORIDA ALSO INCLUDED. V TOTAL IRRIGATED LAND, ALL STATES. ~FOR 1889 AND 1899, CENSUS TOTAL FOR IRRIGATED LAND IN FARMS INCLUDED THE 17 WESTERN STATES, ARKANSAS AND LOUISIANA; FOR 192.9 IRRIGATED LAND FROM WHICH CROPS WERE HARVESTED, SAME 19 STATES; FOR 1934, IRRIGATED CROPS, SAME 19 STATES; FOR (^1939 ) IRRIGATED CROPLAND HARVESTED PLUS IRRIGATED PASTURE, 48 STATES; FOR 1944 AND 19491 TOTAL IRRIGATED LAND 48 STATES. DATA FOR 1909 AND 1919 NOT AVAILABLE.

proportionate increase was in Massachusetts, from 2,049 to 18, acres; the second largest., in Oklahoma, from 4,437 to 34,071 acres; and the third largest, in Michigan, from 2,960 to 13,901 acres. The increases in irrigated land frorn 1939 to 1949 shown by the census of agriculture are in general overstated, as it is believed that the reporting of irrigated land was rnore nearly complete for the 1[)50 than for the HJ40 Ce1JHus. However, undoubtedly, for the country as a whole, a greater iucrease in the acreage of ir- rigated land occui-red from rn:rn to 1949 than for any previous decade. The large increa~e in Texas was caused mainly by ground- water development in the High Plains area; and the increase in California, by ground-water development in the San Joaquin Valley. The increases in irrigated land from 1930 to 1949, shown by the census of irrigation, on the other hand, understate the increases that actually occmred, because duplication and overestimation of acreage irrigated were more nearly eliminated for the 1950 than for the l!l40 Census. In the 17 Western State1> and Arkansas, Louisiana, and Florida, the acreage increased from 21.1 to 26. million acres, or 24 percent. In the 17 Western States alone, the increase was from 20.4 to 24.9 million acres, or 22 percent. By States, the largest increase, from 1.0 to 3.2 million acres, was reported in Texas; the second largest, from 5.1 to 6.6 million acres, was in California; and the third largest increase, from 0. 7 to 1. million acres, was in Arizona. For Colorado, for which the 1950 Census of Agriculture showed an increase of 404,800 acres, the 1950 Census of Irrigation showed a decrease of 276,790 acres (from 3,220,685 acres to 2,943, acres). The acreages for 1949, as shown by the census of agri- culture and by the census of irrigation, differ by less than 2.5 per- cent. It is believed that the acreage for 1939 shown by the census of irrigation was considerably too high because of the duplication and overestimation of the acreage irrigated, and that the acreage shown.by the census.of agriculture may have been too low. Differences between the changes from 1939 to 1949 in irrigated land, as shown by the census of agriculture and the census of irrig11tion, are largely the result of the differences in procedures used for the 1940 and 1950 Censuses of Irrigation for eliminating duplication and overestimation of acreage irrigated, ·although the reporting of the acreage irrigated for the census of agriculture may have been less complete for 1939 than for 1949.

ACREAGE OF IRRIGATED LAND BY MAJOR

DRAINAGE BASINS IN THE 17 WESTERN STATES AND

ARKANSAS, LOUISIANA, AND FLORIDA: 1949 AND 1939

(CENSUS OF IRRIGATION)

NORTH PACIFIC COAST

SOUTH PACIFIC COAST

GREAT BASIN

GULF OF CALIFORNIA

GULF OF MEXICO (EXCLUDING MISSISSIPPI RIVER) MISSISSIPPI RIVER (INCLUDING RED RIVER. OF THE NORTH)

ATLANTIC COAST (FLORIDA)

MILLION ACRES 0 I 2 6 7

10 IRRIGATION^ OF^ AGRICULTURAL^ LANDS

For major drainage basins, the largest acreage of irrigated land in 1949, 6.2 million acres, as shown by the census of irrigation, was in the Mississippi River basin; and the second largest, 6. million acres, in the South Pacific Coast basin. The largest in- crease in irrigated acreage from 1939 to 1949, from 2.5 to 4. million acres, was in the Gulf of Mexico basin excluding the Mississippi River, chiefly as a result of the large increase in Texas. The second largest increase, from 4.6 to 6.1 million acres, was in the South Pacific Coast basin, chiefly as a result of the large increase in California.· Irrigated land in farms in 1949 (1950 Ce.nsus of Agriculture) amounted to 2.2 percent of all land in farms for the country as a whole. In the 17 Western States, irrigated land represented 3.5 percent of all land in farms; in Arkansas and Louisiana, 3. percent; in Florida, 2.2 percent; and in the other 28 States, less than 0.05 percent. Size of irrigated farms.-For the 17 Western States and Ar- kansas, Louisiana, and Florida, the average size of irrigated farms in 1950 was 575 acres. This was an increase of 50 percent over the 383 acres per farm reported for 1940. By States, the average size of farm varied from 195 acres in Washington to 2,651 acres in Arizona. The counting of Indian reservations as single farms was responsible, in part, for the large average size of irrigated farms for Arizona. For the entire United States, the average acreage of irrigated land per irrigated farm increased from 60 acres in 1940 to 85 in

1950. For the 17 Western States, the average increased from 61 to 86; for Arkansas and Louisiana, from 67 to 95; for Florida, from 32 to 60; and for the other 28 States, from 10 to 22 acres.

DEPARTMENT r COMMERCE

The average by States for 1950 ranged from 4 acres for West Virginia to 258 acres for Nevada. Among the 17 Western States, the lowest average per farm was 35 acres for Washington. Of the 289,049 farms with irrigated land in the 17 Western States and Arkansas, Louisiana, and Florida in 1950, 71,428, or 24 percent, had less than 10 acres of irrigated land. About 9 percent of the total, or 26,659 farms, had more than 200 acres of irrigated land per farm. Use of land in irrigated farms.-Most of the land in irrigated farms in the 20 States was pasture and grazing land. For 1949, 76 percent was reported as land pastured; 17 percent, as cropland harvested; 3 percent, as cropland not harvested and not pastured; and 4 percent, as other land in farms. The percentage of the irrigated land represented by pastureland varied by States from 15 percent for Arkansas, to 134 percent for Arizona. Most of the irrigated land, however, was eropland harvested. For 1949, 82 percent was cropland harvested; 16 percent, pasture; and 2 percent, other land in farms. Of the total cropland har- vested in irrigated farms, 74 percent was irrigated. Of the total land pastured, only 3 percent was irrigated. The percentage of all land that was irrigated in irrigated farms averaged 15 percent for the 20 States, and var:ed from 5 percent in New Mexico to 38 percent in Louisiana. For the 20 States, 12 percent of all cropland harvested in all farms was irrigated in 1949, as compared ·with 10 percent in

1939. For the 17 Western States, 39 percent was irrigated in 1949, as compared with 42 percent in 1939. The percentage of all cropland harvested that was irrigated in 1949 varied from less

LOCATION OF MAJOR DRAINAGE BASINS IN THE 17 WESTERN

STATES AND ARKANSAS,

LOUISIANA, AND FLORIDA

\ GULF OF MEXICO I EXCLUDING MISSISSIPPI RIVER (V)

12 IRRIGATION^ OF^ AGR1CULTURAL^ LANDS

Irish potatoes. Only 2.3 percent of the production of winter wheat, however, was on farms where the entire crop was irrigated. An additional 2.1 percent of wheat production was on farms where the crop was partly irrigated. Only 4.2 percent of the corn harvested for grain was on farms on which the entire acreage was irrigated, and 3.0 percent was on farms on which the crop was partly irrigated. For cotton, 28 percent of the production was dn farms on which the entire acreage was irrigated, and 5 percent on the farms on whic\l only a part of the acreage of the crop was irrigated. Generally, the percentage of individual crops harvested on farms on which the entire acreage was irrigated was much larger in the more arid Mountain and Pacific States than in the Great Plains and Southern States. Yields per acre of most crops on irrigated land were much higher than on nonirrigated land. The average yield per acre for farms on which all the crop was irrigated was more than double the yield per acre for nonirrigated land for cotton, alfalfa seed, barley, sorghums harvested for grain, and mixed grains harvested for grain. The yield per acre of crops irrigated was more than three times the yield per acre on nonirrigated land for spring wheat, flaxseed, dry beans, and red clover seed. In making these comparisons, it should be noted that the irrigated and non- irrigated crops are not necessarily grown on land of comparable quality nor under other conditions that are comparable. Hence,

the difference in yield per acre on irrigated and nonirrigated land may be, in part, the result of factors other than irrigation. IRRIGATION ENTERPRISES A total of 123,926 irrigation enterprises was reported in the 1950 Census of Irrigation for the 17 Western States and Arkansas, Louisiana, and Florida. This was an increase of 28, 661, or 30 · percent, over the 95,265 reported for 1940. Types of irrigation enterprises.-The number of single-farm enterprises reported in 1950 was 113,358, an increase of 23, 730, or 26 percent, over the 89,628 "individual and partnership" enterprises reported in 1940. Increase in single-farm enterprises accounted for most of the increase in both total number of enter- prises and total acreage of irrigated land between the two censuses. This was because the new irrigation was brought about chiefly by development of irrigation from ground water by individual farmers. A total of 12.9 million acres was reported irrigated direct by single-farm enterprises in 1949, as compared with 8.0 million acres irrigated by "individual and partnership" enterprises in

1939. (It should be kept in mind that, for 1949, acreage irrigated direct by 2 or more enterprises is included for each in the figures on acres irrigated, and for 1939, acreage irrigated by a primary enterprise and by one or more supplemental enterprises is in-

IRRIGATED ACREAGE OF SPECIFIED. CROPS AND PASTURE IN THE 20 STATES: 1949*

CROPS AND PASTURE

PASTURE ALFALFA HAY COTTON

RICE WILD HAY ORCHARDS, VINEYARDS AND NUTS BARLEY DRY BEANS ("'eluding Limas) CLOVER OR Tl MOTHY HAY ALL SORGHUMS ALL CORN SPRING WHEAT SUGAR BEETS

WINTER WHEAT OATS FOR GRAIN IRISH POTATOES ALFALFA SEED SMALL GRAINS CUT FOR HAY FLAXSEED MIXED GRAINS 0

ORY PEAS(excludlno Cowpeas) RED CLOVER SEED HOPS SWEET CLOVER SEED

0 0.5 1.0 1.

Million Acres

• Excluding the irrigaled ocreage of o crop on farms where only part of crop was irrigated,

2.5 3.0 3.5 4.

SUMMARY (^13)

eluded for each. The total "acres irrigated" by all enterprises therefore exceeds the acreage of irrigated land, and for any group of enterprises "acres irrigated" does not necessarily repre- sent a corresponding proportionate part of the irrigated land.) About 76 percent of this increase was in Texas and California. The percentage of the total acreage irrigated direct by all enter- prise:o that was reported for single-farm enterprises varied by States from 4 percent for North Dakota to 95 percent for Arkansas. The reported number of unincorporated mutual (or coopera- tive) enterprises increased from 1,690 in 1940 to 6,488 in 1950, and the acreage irrigated by such enterprises, from 1.0 million acres to 2.1 million acres. These large increases are largely the result of classifying in 1950 as "unincorporated mutual," enter- prises that were classified "partnership" in 1940, and the more complete reporting of this type of enterprise in 1950, rather than actual changes during the decade. By States, the largest number of unincorporated mutual enterprises were in Colorado, with 1,579; the second largest number, in Montana, with 994; and the third largest number, in California, with 709. On the basis of acreage irrigated by such enterprises, Oolorado also ranked first, with 559,708 acres; Montana, second, with 323,918 acres; and Wyoming, third, with 275,597 acres. The number of enterprises other than single-farm and unin- corporated mutual increased only from 3,947 in 1940 to 4,080 in

1950. The acreage irrigated reported for such enterprises de- creased from 15.4 million to 12.9 million acres. This decrease resulted largely from the use of procedures by which overestima- tion and duplication in reporting of acreage irrigated were more nearly eliminated for 1950 than for 1940, rather than to an actual change. Incorporated mutual enterprises increased only from 2, 705 in 1940 to 2,886 in 1950. Colorado had the largest number in 1950, with 686; Utah was second, with 634; and California was third, with 561. The 'acreage irrigated by incorporated mutuals, 5. million acres, was larger than by any other type of enterprise except single-farm. Among the States, on the basis of acreage irrigated, Colorado ranked first with 1. 7 million acres; Idaho, second, with 1.0 million; and 1Jtah, third, with 0.9 million. Th_e total number of commercial enterprises increased from 285 in 1940 to 446 in 1950. In the 17 Western States, the number decreased from 245 to 131, as a result of commercial enterprises being taken over by mutual or district organizations or ceasing to op.erate as irrigation enterprises. In Louisiana, however, the reported number increased from 28 to 270, and in Arkansas, from 2 to 38. The increase in these States was the result, in part, of a change in definition or the interpretation of definition from 1940 to 1950. Most of the commercial enterprises in these States were operated by individual farms but supplied more water to other farms than to the farm by which operated. In 1940, some of such enterprises were classified by type as "individual and partnership." In 1950, the number ·of district enterpriseS' reported was 489, as compared with 441 in 1940. By States, California had the largest number, 114, in 1950; Washington was second, with 74; and Idaho, third, with 54. A total of 5.0 million acres irrigated direct was reported for district enterprises for 1949. By States, Cali- fornia ranked first in acreage irrigated direct with 1,821,295; Texas, second, with 590,529; and Idaho, third with 567,261 acres.

In 1940, there were 97 enterprises operated by the Bureau of Reclamation with 3.3 million acres irrigated. During the decade of 1940 to 1950, the operation of many of these was taken over by water-user organizations such as districts and mutuals, and in 1950, these enterprises were classified according to the type of enterprise by which they were operated. For 1950, only 37 enterprises, with 682,413 acres irrigated direct, were reported as operated by the Bureau of Reclamation .. Bureau of Reclamation

projects that were operated by water users numbered 79 and reported 1.5 million acres irrigated direct; and 247 enterprises, with 2.2 million acres irrigated direct, reported water received from Bureau of Reclamation projects. The combined acreage irrigated direct by enterprises receiving all or part of the irrigation water from Bureau of Reclamation projects was 4.4 million acres. This, total does not include single-farm enterprises that received water from Bureau of Reclamation projects, nor a number of small multiple-farm enterprises that received a part of the water supply indirectly. The reported number of U. S. Bureau of Indian Affairs enter- prises decreased from 188 in 1940 to 141 in 1950, and the number of acres irrigated, from 515, 765 to 506,076. These decreases may be attributed chiefiy to the fact that a number of small irrigation projects constructed by the Bureau of Indian Affairs and included as Indian enterprises in 1940, were classified in 1950 as single-farm enterprises because they were operated by individual farms. From 1940 to 1950, the number of State enterprises decreased greatly in all States except Montana. In 1940, a total of 143 State-operated enterprises with 19,022 acres irrigated was re- ported. Of these, 105 enterprises with 9,110 acres irrigated were , in Montana; and 38, with 9,912 acres irrigated were in 11 other States. In 1950, only 31 enterprises were reported, of which 29 were in Montana. The number of acres irrigated, however, increased to 51, 782, of which 51, 7 52 acres were in Montana. City enterprises, relatively unimportant in the supplying of irrigation water, decreased from 62 in 1940 to 50 in 1950, and the number of acres irrigated from 91,187 to 56,845. In 1940, 24 of these enterprises and 46,419 of the acres irrigated, and in 1950, 22 of the enterprises and 39,929 of the acres irrigated, were in Califomia. Interrelationships between irrigation enterprises.-Many irri- gation enterprises do not deliver all of their irrigation water direct to farms, but deliver part or all to other irrigation enterprises which may deliver it to farms or in turn pass part or all on to other enterprises. In some cases, the water is passed on through several different enterprises before it reaches farms. A farm may buy water from one enterprise, but the water is delivered to the farm by a different enterprise. Some enterprises own no irrigation water, and obtain none from natural sources, but merely act as carriers of water for other enterprises. One of the difficult prob- lems in taking the census of irrigation is the separat.ion of data affected by these interrelationships so that duplication in totals will be minimized. Of the 10,568 multiple-farm enterprises in the 20 States in 1950, 8 percent obtained part of their water from other enterprises, and 11 percent obtained all from other enterprises. Of the 15.0 million acres irrigated direct by multiple-farm enterprises, 37 percent were irrigated by enterprises that received part or all of their water from other enterprises. The delivery of part of their water to other enterprises was reported by 1,777 multiple-farm enterprises, or 17 percent of all enterprises; and the delivery of all their water to other enterprises was reported by 323 or 3 percent. The 1,777 enterprises that delivered part of their water to other enterprises, irrigated 9. million acres direct or 61 percent of the total acreage irrigated direct by multiple-farm enterprises. Of the 113,358 single-farm enterprises, 2 percent received part and_?_ percent received all of their water from other enterprises. Enterprises that delivered water direct to farms and neither obtained from, nor delivered to, other enterprises more than 10 percent of their irrigation water, have been termed "cornplete- system" enterprises. Comparisons of data for enterprises classified by type of water and by acreage irrigated are limited to the "complete-system" enterprises in order to provide significant information.

SUMMARY (^15)

COMPARISON OF THE NUMBER AND CHARACTERISTICS OF SPECIFIED IRRIGATION WORKS,

FOR THE 20 STATES: FOR 1940 AND 1950

PERCENT OF 1940

DIVERSION DAMS

IRRIGATION RESERVOIRS

CAPACITY OF RESERVOIRS

SUPPLY CANALS AND DITCHES

FLOWING WELLS

PUMPED WELLS

AVERAGE PUMPING LIFT FROM WELLS

IRRIGATION PUMPS

ELECTRIC MOTOR

0 100 120 140

49,452 MOTORS

(^160 )

• 1950

w:mtl 1s

200

OTHER MOTORS AND ENGINES (^) i!iliiiiiiii!i!!U>U:i!UlH%Ul!!iH:iHL2s,s3.4'. .. M(J19~s)fiH>!Hii!H!l!li?:i!iii!%Hi!!

Capital investment.-The census data on capital investment of irrigation enterprises are far from precise. The amounts re- ported for the individual and many of the smaller mutual enter- prises are largely eRtimates. The greater part of the works of such enterprises was built by the owners or their predecessors who kept no records of funds or labor expended. The works of many of the iarger enterprises were built decades ago, and the enterprises have gone through repeated changes in ownership, organization, and valuation. The total capital investment of irrigation enterprises reported in 11)40 for the 20 States was $1,059 million. The reported new capital investment from 1940 to l!l50 was $829 million. Adding these two figures gives $1,888 million as the total capital invest- ment in lll50, an increase of 78 percent over 1940. The largest total capital investment in lll50 in any State was in California, with $640 million. The State of Washington had $ million, the second largest capital investment. The rank of Washington is largely the result of large investment of the U. S. Bureau of Reclamation in the Grand Coulee and other projects in that State. · Colorado was third with $163 million. California, Washington, and Texas led in new investment from 1940 to 1950, and had 63 percent of the capital investment made from 1940 to 1950. Average capital investment per acre of irrigated land for the States included in the census of irrigation, increased from $36 in 1920 to $46 in 1930, $50 in 1940, and $72 in 1950. By States, the average per acre in 1950 varied from $28 in Nevada to $296 in Oklahoma. The large investment per acre in Oklahoma resulted from about three-fourths of the irrigation ·in the State being supplied by one large enterprise with relatively large capital

I

investment. 'rhe second largest average investment per acre was in Washington, with $288, chiefly as a result of the large recent investment in the Grand Coulee project for which only a very small part of the land to be irrigated was actually irrigated in 1949. The third largest average per acre was in Arizona. Since the classification of enterprises by type for l!l50 is not comparable with the classifications for H)40, it is not possible to obtain (1) accurate data on the total capital investment by type of enterprise for 1950, and (2) comparable data on total capital investment by type of enterprise for 1940 and 1950. The total capital investment by type of enterprise shown in the tables has been obtained by adding the capital investment from 19'10 to 1950 for a type of enterprise to the total capital investment for the corresponding type for 1940. As explained. under the para- graph "type of enterprise," some enterprises were classified dif- ferently in 1950 and 1940. This procedure results in the under- statement of the total capital investment for some types of enterprises and an overstatement for other types. The change in the classification had little effect on the totals for single-farm and unincorporated mutual enterprises combined and totals for all types other than single-farm and unincorporated mutual enterprises. Hence, for a combination of single-farm and unin- corporated mutuals and a combination of all other types, the 1950 investment represents approximately accurate totals for these groups of enterprises and provides a total comparable with the 1940 investment for the same groups of enterprises. Comparative figures for these two groups of types of enterprises are shown for the 17 Western States in table 67. The enterprises classified by type as "single-farm" in 1940 and as "unincorporated mutual" in 1950 were mostly enterprises that

16 IRRIGATION OF AGRICULTURAL LANDS

AVERAGE CAPITAL INVESTMENT OF IRRIGATION ENTERPRISES PER ACRE OF IRRIGATED LAND, BY STATES: CENSUS OF 1950

0 1;0 100

Oklahoma

Washington

Arizona

California

New Mexico

North Do kola

South Dakota

Netiraska

Idaho

Oregon

Colorado

Florida

Utah

Texas

Montano

Kansas

Wyoming

Louisiana

Arkansas

Nevada

provided water to less than 5 farms. If the data for unincor- porated mutual enterprises that provided water to less than 5 farms are combined with those for single-farm enterprises, approx- imately comparable figures for capital investment of single-farm and multiple-farm enterprises for the 20 States are obtained for 1950 and 1940. These data are as follows:

Capital investment (dollars) Type of enterprise and year Total

Slngle-!nrm: 1950____________________________________ 1940 ______________________ ,_____________ (^) 194,523, 482,149, (^530969) Multlplc·farm: 1050____________________________________ 1, a&1, 256, 177 1940____________________________________ 864, 955, 153

Average per A vera~e per enterprise ga~~';i ifk~ct

4, 448 2, 166 218, 456 153, 442

38 24 07 5a

DOLLARS 150 200 250 300

Indebtedness.-Data on indebtedness and arrearage on indebt- edness were obtained for 1950 only for multiple-farm enterprises, and in 1940, only for enterprises providing water for 5 or more farms. The total number of enterprises reporting indebtedness decreased from 1,419 in 1940 to l,·155 in 1950. The total reported indebted- ness, however, increased from $387 million to $696 million. The average indebtedness per acre of all irrigated land increased from $18.41 in 1940 to $26.52 in 1950. In 1950, the average indebted- ness per acre of all irrigated land varied by States from 0 for Arka,nsas to $186 for Washington. The largest part of the indebtedness was for Bureau of Recla- mation projects.. Of the total of $696 million, more than one-half or $350 million, was reported for projects operated by the Bureau in 1949. An additional $159 million was for Bureau of Recla- mation projects operated by water users, and represented mostly indebtedness to the United States Government. For enterprises

18 IRRIGATION^ OF^ AGRICULTURAL^ LANDS

of the irrigation of a larger proportion of the acreage by pumping in 1949 than in 1939, and also of water being supplied by the more recently constructed irrigation projects which in general have higher costs than projects constructed earlier. On the basis of the calculated average quantity of water delivered to farms per acre of irrigated land, the average cost of water per acre-foot was $1.66 in 1949 as compared with $0.83 in 1939.

COST OF IRRIGATION WATER

TO FARMS PER ACRE OF IRRIGATED LAND,

BY STATES: 1949 AND 1939

ARIZONA CALIFORNIA LOUISIANA ARKANSAS WASHINGTON TEXAS FLORIDA NEW MEl<\CO

NEBRASKA NORTH DAKOTA OKLAHOMA IDAHO KANSAS OREGON UTAH

COLORADO SOUTH DAKOTA MONTANA WYOMING

NEVADA

DOLLARS PER ACRE 0 2.50 5.00 7.50 10.00 12.

---

f,iu/27!7//I 1939

By States, the average cost of water per acre of irrigated land in 1949 varied from $0.87 in Nevada to $14.78 in Arizona. Of the total acreage irrigated direct in the 20 States, 39 percent was reported for enterprises with average costs of less than $2 per acre irrigated direct, while 15 percent was for enterprises with average costs of $10 or more per acre. For single-farm enterprises in 1949, and for enterprises serving less than 5 farms in 1939, the costs of operation and maintenance were considered to represent the tota1 cost for water to farms. The 1950 Questionnaire for multiple-farm enterprises contained an inquiry regarding the part of the total cost for purposes other than for operation and maintenance. For enterprises serving more than 5 farms in 1939, "total annual charges" for water and also operation and maintenance cost were reported. The differ- ence between total annual charges and operation and maintenance · cost represented costs other than for operation and maintenance. Cost of water to farms for purposes other than operation and maintenance, as thus obtained, averaged $0.59 per acre of irri- gated land in 1949 as compared with $0.38 in 1939. The greater cost for purposes other than operation and maintenance in 1949

as compared with 1939 indicated a higher rate of paywent either on principal and interest of indebtedness or for new capital investment. By major drainage basins, the lowest average total cost of water to farms per acre of irrigated land in 1949 was $2.02 for the Great Basin, and the highest, $9.71 for the South Pacific Coast basin. For unincorporated mutual enterprises, the average cost per acre irrigated direct was only $1.37 as compared with $6.00 for single- farm enterprises, $3.53 for incorporated mutuals, $5. 71 for dis- tricts, $6.43 for U. S. Bureau of Reclamation enterprises, and $6.81 for commercial, Indian, State, and City enterprises combined. For complete-system enterprises that obtained all water from surface sources by gravity, the average cost per acre irrigated direct was $1.27; for those that obtained all water from surface sources by pumping, $7.40; and for those that obtained all water from pumped wells, $9.22. For enterprises that irrigated 1 to 99 acres direct, the average was $8.57 per acre; for those that irrigated 100 to 199 acres, $5.27; for those that irrigated 1,000 to 9,999 acres, $4.04; and for the largest enterprises, those that irrigated 10,000 acres or more, $5.46.

WEATHER AND AVAILABLE WATER, 1949 AND 1939

The extent of irrigation in a given year is influenced by weather conditions and by the available water in streams, reservoirs, and ground water supplies. The 6 charts on pages 20, 22, and 24-26 show comparative weather and water-supply data for selected points in the 17 Western States for the 1949 and 1939 irrigation seasons. The first chart shows a computed index of "irrigation require- ment" for 1949 and 1939 for selected weather stations. The other charts pertain to suppl:y of irrigation water. Those for stream flow during the winter preceding the irrigation season, stream flow during the irrigation season, and water stored in reservoirs show data for the 1949 and 1939 seasons relative to "normal" years. The last 2 charts show depth to ground water in selected observation wells during the 1949 and 1939 irrigation seasons, and on or about March 31, for the years 1930 to 1950. Index of irrigation requirement.-Within the last decade, sev- eral methods of varying complexity have been devised to estimate, from climatic data, water requirements of crops. All these methods have been based on rather limited experimental data and involve computations which, if applied to a number of years, would entail considerable expenditure of time and funds. The method used to compute the index of irrigation requirement necessitated only data readily available at a sufficient number of locations and over a long enough period to establish satisfactory "normals." Evaporation from a water surface for the growing season minus the precipitation for the same period, expressed as a percentage of "normal," is used as the index of irrigation requirement. This index is based on the assumption that evaporation from a water surface is an adequate, even if indirect, measure of quantities of water used by crops and other vegetation. For practical pur- poses, this assumption is essentially correct, since evaporation from a water surface does in effect integrate the several climatic factors that control transpiration by plants. This index assumes also· that all precipitation occurring during the growing season replenishes available soil moisture or is otherwise utilized by the growing crops. This assumption is ·not always correct because (a) some of the precipitation falling during the growing season, particularly in the arid West, occurs in such small amounts that it evaporates before it becomes available to plants, and (b) on sloping land, some of the rainfall runs off into waterways and streams and is not available to plants. However, practically everywhere in the 17 Western States evaporation during the growing season is so much greater than the total precipitation for the same period that any error introduced by this assumption has little influence upon the index of irrigation requirement.

SUMMARY 19

OCCURRENCE IN PERCENT OF TIME OF SPECIFIED VALUE OF INDEX OF IRRIGATION REQUIRE-

MENTS AT PROSSER, WASHINGTON ANO ARCHER, WYOMING: 1927 TO 1946

INDEX*° {Inches) (^) 2.5% OF TIME LESS THAN 31 INCHES PROSSER,^ WASHINGTON^ 25% OF Tl l\IE MORE THAN 34 I NCH ES

2.5% OFTIME LESS THAN 19 INCHES. ARCHER,^ WYOMING^ 25% OF TIME lllORETHAN 28 INCHES

10 25 50 PERCENT OF TIME

v

For computation of the index of irrigation requirements, all nv.ailable published and unpublished records of evaporation and of concurrent precipitation in the 17 Western States were examined. This examination revealed that .a r-0presentative record period should include both the dry '30's and the wet '40's. It was decided to use the period from 1927 to 1946. A longer period would have been preferable, but would have reduced the number of stations for which usable records were available. The choice of stations was further restricted because ·it had to be limited to those with records both of evaporation and of precipitation for both 1939 and 1949. By expressing the index of irrigation require- ment as a percentage of normal, ·it was possible to use records of "Class A" Weather Bureau Stations and of the Bureau of Plant Industry Stations without converting the evaporation data to comparable units of measure. It was necessary in order to obtain greater coverage of area to include records for a few stations with records for a period of less than 20 years, and also for some stations with records for only part of the growing season. Records for sta- tions with records of less than 20 years were used only to provide a comparison between 1949 and 1939 and not for establishing a long-time "normal." The 46 stations for which records were used are indicated in the accompanying table.

For each station, the values of evaporation minus precipitation (E-P) for the growing season (April to September) of each year, or for the part of the season for which records were available, were computed and arranged in ascending order of magnitude. Plot- ting positions in i;iercent of time of occurrence were computed for 2(n-l)X 100 each value by the formula · 2

T where n is the order of

magnitude and T is the number of years for which records were used. These values of E-P were plotted against percent of time on logarithmic-probability paper. Freehand curves were drawn through the plotted points, and values were recorded on these curves for 25, 50, and 75 percent of the time period. The value at the 50 percent of the time period was taken to be the "normal." The E-P values for 1939 and 1949 falling in the upper quartile of the probability curve were designated as "much above normal," those in the second and third quartiles as "normal or nearly normal," and those in the lowest quartile as "much below normal." Thus, "much above normal" values are in the range of values to be expected in 25 percent of the years with highest values; "much below normal" are in the range of those to be expected in 25 percent of the years with lowest values; and "normal or nearly