A Thesis Submitted to the Faculty of the in Partial Fulfillment of The

Water management for the area downstream from the Imperial Dam on the Colorado River.

Item Type Thesis-Reproduction (electronic); text

Authors Gordon, Yoram,1928-

Publisher The University of Arizona.

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Link to Item http://hdl.handle.net/10150/191496 WATER MANAGEMENT FOR THE AREA DOWNSTREAM

PROM THE IMPERIAL DAM

ON THE COLORADO RIVER

Yoram Gordon

A Thesis Submitted to the Facultyof the

GRADUATE COMMITTEE ON HYDROLOGY ANDWATER RESOURCES In Partial Fulfillment of the Requirements For the Degree of

MASTER OF SCIENCE In the Graduate College

THE UNIVERSITY OF ARIZONA

1968 STATEMENT BY AUTHOR

This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judg- ment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author.

SIGNED: /

APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below:

K /// LD D.EVANS //Date ACKNOWLEDGMENTS

I wish to thank Dr. D. D. Evans, Dr. M. M. Kelso, and Mr. T. Maddock, Jr. for their advice, assistance and time whichthey proffered me so generously. With gratitude I acknowledge the cooperation of Mr. C. C. McDonald and the staffs of the Yuma and Tucson offices of theUnited States Geological Survey, and Mr. W. A. Von Schoelerof the Internation- al Boundary and Water Commission, Yuma. To the Imperial and the North Gila Valley Irrigation Districts,the Wellton-Mohawk and the Yuma Mesa Irrigation and Drainage Districts, the Coachella Valley County Water District, the Yuma CountyUsers' Association, and the Arizona Water Company, I express myappreciation for their cooperation. I am particularly thankful to my wife, Judy,for her invaluable encouragement, help, and patience.

111 TABLE OF CONTENTS

Page

LIST OF ILLUSTRATIONS vi

LIST OF TABLES viii

CHAPTER

1 INTRODUCTION 1

2 THE RIVERS 4

Colorado River 4 Gila River 10

3 THE DAMS 12

Imperial Datn 12 Laguna Dam 15 Morelos Dam 17

4 THE DRAIN CANALS . 19

Wellton-Mohawk Main Outlet Drain 20 Main Outlet Drain Extension 21 Yuma Main Drain 26

5 INTERSTATE AND INTERNATIONAL ASPECTS . . . 31

The Colorado River Compact 31 The Boulder Canyon Project Act 32 The 1944 Treaty between the United States of America and The Republic of Mexico . 34

WATER BALANCE 36

The City of Yuma 42

iv V

TABLE OF CONTENTS--Continued

CHAPTER Page

7 GROUNDWATER 44

49 8 WATER QUALITY 0

9 WATER COST 54

Cost of Groundwater 59

10 DISCUSSION 61

11 CONCLUSIONS 65

APPENDIX A. ENGLISH TEXT OF MINUTE 218 DATED MARCH 22, 1965 68

APPENDIX B.TEXT OF COLORADO RIVER COMPACT 72

LIST OF REFERENCES 78 LIST OF ILLUSTRATIONS

Figure Page

1 Map and Operational Diagram of the Lower Colorado River 5

2 Imperial Dam Looking Northward with All American Canal in Foreground 13

3 Desilting Works at the Head of the All American Canal 14

4 All American Canal Looking Southward from Imperial Dam 16

5 Morelos Dam 18

6 Wellton-Mohawk Drainage Conveyance Facilities 23

7 Main Outlet Drain Extension 24

8 Gate and Gage on the Main Outlet Drain Extension 25

9 Main Outlet Drain ExtensionDischarge Location No. 2 above Morelos Dam 27

10 Main Outlet Drain Extension - Discharge Location No. 3 below Morelos Dam 28

11 Yuma Main Drain Pumping Station near San Luis . . 30

12 Schematic Diagram Showing Gaging Stations between Imperial Dam and the Southern International Boundary, 1960-1965 37

13 Schematic Diagram Showing Gaging Stations between Imperial Dam and the Southern International Boundary, 1966 40

vi vii

LIST OF ILLUSTRATIONS--Continued

Figure Page 14 Map of the Yuma Area Showing Thickness of Alluvium 46

15 Map of the Yuma Area Showing Configuration of the Water Table, 1965 48 16 Yearly Weighted Average Total Dissolved Solids at Critical Points in the Colorado River 51 LIST OF TABLES

Table Page

I Water Budget 41

II Water Cost 56 ABSTRACT

The Colorado River is the major supplier of water in the area of the lower Colorado below Imperial Dam. In this area the water is used in the United States -- by the states of Arizona and California -- and also in the Republic of Mexico. The water of the Colorado River is divided in accordance with various agreements. The Colorado River Compact guarantees thedelivery of water to the Lower Basin States. The Boulder Canyon Project Act provides for the division of the water among these states.The Treaty of 1944 stipulates the quantity of water which must be delivered toMexico. It now seems likely that there will be a shortageof water in this area within the next thirty years.On the other hand, water of poor quality flows abundantly in the drain canals.In fact, the discharge of the drainage water into the river channel is theprincipal factor contri- buting to the deterioration of the quality of theColorado River.The increased salinity of the river water creates local aswell as international problems. Further comprehensive study is needed in order to evaluate the alternative solutions to these problems.

ix CHAPTER 1

INTRODUCTION

Few natural resources are as essential for human life as water. Yet, not many resources are as abused as water. Few resources are as abundant as water, while being scarce at the same time.Rare is the resource that is so inexpensive as well as priceless.Few physical phenomena have been investigated so much and yet there is solittle really known. Water is one of the fundamental inputs of many economic models, but until now no economic value for it has been agreed upon. Water cases have been brought before the courts sooften, but the water laws remain ambiguous and they have failed to gain universal acceptance. In the scientific era of the late twentieth century, wateris still not treated like a natural resource, mainlybecause of the beliefs or the images attached to it.Kelso, in his paper "The Water-Is-Different Syndrome, or What Is Wrong with the WaterIndustry" (1967), mentions five "images" of water: the survival image, theirrigation fundamentalism image, the desert image, the idyllic idol image,and the recreation image. To an extent, water is an essential (e.., fordrinking). Beyond the basic needs, however, it is not necessarilyessential at all costs.It

1 2 is convenient, important, and good to have, but, nevertheless, should it not be figured in economic terms as are othernatural resources? Undoubtedly, it is difficult to overestimate the importance of water in any economy. This is all the more true in adeveloped economy for which water provides, besides the essentials for life, many con- veniences for the home, agriculture, industry, recreation, etc. With the increased demand for water, many problems have arisen which have made the field of water resources far more diverseand more

complex.It has become more and more difficult to getfresh water since there are some streams which are completelyappropriated and others which are so polluted that their water cannot servefor any beneficial use. In some places, the groundwater is so deepthat the costs of pumping are prohibitively expensive.In other areas, pumping is not permitted at all. Whereas appropriation once involvedmerely registration, today it may be a complicated legal process.Where once the cost of water was nil, in today' s competitive market it maybe the determining factor which causes the farmer to shiftfrom one crop to another or even to abandon farming altogether. Thus, the field of water resources has become anintegrated area involving the different disciplines.No longer is one discipline alone sufficient for solving the problemsencountered. The fields are so inherently interwoven that any attempt toisolate water, per Se, from its environment is futile.For example, no technical aspect can be 3 properly evaluated without a consideration of the economic soundness of the project, and no project can materialize if it is not based on sound legal grounds. The examples are endless. It can be stated that in order to conduct any comprehensive water resources study, many diverse fields of knowledge must be considered. These include hydrology, economics, engineering, geology, statistics, law, political science, biology, and sociology. Without a clear understanding of the numerous varied factors, without integration of all the pertinent data, no serious comprehensive study can result. With these principles in mind, this study was undertaken. In this project, the various aspects of the water in the areaof the lower Colorado River were studied. Data were collected onthe actual physical conditions of the natural and artificial streams, onthe cost and the quality of the water in the area, and also on theinterstate and international aspects of the problem. The data arepresented in order to delineate and describe individually the conditions inthe Colorado and Gila rivers and in their basins, the drain canals,the groundwater, the dams, water quality, and water cost.The pertinent legal compacts are also discussed. Finally, the data are evaluated with reference tothe over-all problem. No alternatives for solutions areproposed at this time. Rather, possible alternatives for various managementpractices will be the subject of further study. CHAPTER 2

THE RIVERS

The Colorado River is of course the most importantriver in the area. downstream from Imperial Dam (Figure 1).The Gila River is the main tributary of the Colorado in thisarea.

Colorado River The Colorado River constitutes the majorsource of supply of water in the area extending from Imperial Dam in the United States southward to Morelos Dam in Mexico.

The Colorado River and its upper tributaries arise in themoun- thins of Wyoming, Colorado, and Utah where precipitation is high, falling mostly as snow. The Colorado River flows about 1,440 miles to the Gulf of California.The drainagebasincovers about 246,000 square miles. Of these, 61, 400 square miles are below Imperial Dam, including 2,000 square miles in the Republic of Mexico (International Boundary and Water Commission, 1960). The following areas comprise the Colorado River basin: one-quarter of Wyoming, the western half of Colorado, the eastern half of Utah, one-sixth of New Mexico, practically all of Arizona, and small parts of Nevada, California, and the Republic of Mexico (Olson, 1926).

4 NOTES .-' Ss-S0.50 RivenMop compiled miles shown fromGeologicalReclnmotice,Secliotal ore Coast Oppronirnufely and Aeronautical Suroey Geodehcduto. or902 Surueyestablished Charfoand to 1923. byBureau of L.AGUNA(Overlie's DM lV,,) Q.nICr900, 'P ? 'P 2,0 N 'N GGn,2i090 Me,cnOSi9O 0,6525 estrroraland SCALE OF MILES SICYuuui 50600 ru,CuOt--. 9_- 25 Ore 69505 flurlh 6,50 POnCeOl lrr poal El Centro SIC 093 920d 9. inC 00000,0 Heber MORELOS5 Pwnp,nQP.ortNo2 CALF IcO ii noicali OAM PvnrC,nQVo,no 250Cr Mesa Pcs"p,nQ Pie,, 7 SPILLWOP OPERATIONAL DIAGRAM NO SCALE Figure 1 Map and Operational CE RiverDiagram of the Lower Colorado 0oirdorp Pe,np,nO PioCi' Lr ( Adapted from ofUnited Reclamation States Bureau map) 6

The Colorado River constitutes the boundary between Arizona and California. From Yuma it flows southward for 80 miles through the Republic of Mexico, emptying into the Gulf of California at its northern tip. Physical features divide the Colorado area in the United States into two great basins which are separated by deep canyonscutting through high and rough plateau. The Upper Basin in Colorado, New Mexico, Wyoming, and Utah furnishes 85% of theflow of the river.The Lower Basin in Arizona, Nevada, and Californiasupplies 15% of the river flow (Olson, 1926). At one time, the Gulf of California extendedmuch farther to the northwest.It once reached as far as Indio,California which is about 144 miles northwest of the present mouthof the river.Sediments trans- ported by the river were borne intothe gulf for centuries. They formed a long, cone-shapeddelta which stretched across the entirewidth of the gulf and eventually separated the waterin the north from that in the south. The water in the northern section wascut off without replenishment(except by rare floods), and itgradually evaporated, leaving a verylarge depression. The bottom of this sectionof the ancient gulf is referred to as the "SaltonSink;" it is 234 feet below sea level atits lowest point. At the beginning of the twentieth century,water for irrigation was being diverted from theColorado River to the Imperial Valley which is 7 located in the Salton Sink in California.During1904,additional diversions were made at points downstream from theheadgate (Hely,

Hughes, and Irelan,1966).In November of that year, before these channels could be properly protected, severefloods caused erosion of the channels about three miles below theCalifornia-Mexico line (Encyclopaedia Britannica,1964)0 Asa result, the flow of theColorado River was diverted northward into thelow-lying Salton Sink, thereby creating the Salton Sea.During the period of uncontrolleddiversion, the Salton Sea covered 500 square milesand reached a depth of80feet (Hely

1966).

By February1907,the river had been diverted back toits old channel. The only flow that sustainsthe Salton Sea at present isdrain-

age water fromirrigated land in the Imperialand Coachella valleys. The Salton Sea is now 50 miles inlength and 10 to 15 miles inwidth, with a total water area of 300 squaremiles and a depth of about60feet.Like all closed lakes, it is verysaline, at one time reaching40,000parts per million,although the salinity isconsiderably lower (about 33,000 parts per million) at present(Hely etal., 1966) The Colorado River is oneof the most important riversin the world as far as irrigation isconcerned.It is one of the mostappropri- the source ated rivers as well.In1860,it was a wild and muddy stream, of many floods duringthe spring thaw.It was a river that wasnavigable as far north asFort Callville above the presentlocation of Hoover Dam 8

(Wilbur and Ely, 1948). Today it is but a small reminder of its old glory. The flows that even in the late 19 50's were appreciable are now very small. The major dams which were constructed upstream formed lakes that control the flow.(Incidentally, lakes Mead and Powell, behind Hoover and Glen Canyon dams respectively, can store more than seven times the quantity of water allocated annually to the Lower Basin states.)At the same time, the diversions for irrigation and other uses deplete the river. As a result, very little flow reaches the Gulf of California. Southward from the Imperial Dam, the flow diminishes considerably. The only other source of fresh water in this area had been the Gila River, which is no longer a source of water.(See section below on the Gila River.) The only water which does flow into this sectionof the Colorado River consists of drainage water from local irrigation areasand effluents from various wasteways. Since the Colorado River is so controlled and its waterhas been so completely appropriated, itsimportance in general, and to the area under study in particular, is enhanced and cannotbe overemphasized. The area which is supplied with water from the ColoradoRiver has been increasing continually.In the Upper Basin, there were 310,000 irrigated acres in 1896 but about 1,400,000 ever since1910.In the Lower Basin, 530,000 acres were under irrigationin 1910 and 746,000 9 in 1960 (Olmsted and McDonald, 1967).By 1962, 1,063,500 acres of land were irrigated below Imperial Dam; of these, 623,500 acres were in the United States and 440,000 were in Mexico (International Boundary and Water Commission, 1962). Besides water for agricultural use, the Colorado River also supplies water for domestic consumption. The main city in Arizona supplied by the Colorado River is Yuma which received 9, 300 acre-feet during the 12-month period ending November 1967 (Arizona Water Company, 1967). The population of Yuma has grown from 4,200 in1920 to 24,000 in 1960, according to the United States Censusfigures for these years.In California, the Colorado River supplied Los Angeles with 1,178,000 acre-feet in 1965 (Olmsted and McDonald,1967). The population of the metropolitan area has grown from 576,000 in1920 to 2,500,000 in 1960. All the water of the Colorado River has beenallocated (Olmsted and McDonald, 1967).If all the water rights below LeeFerry1are exercised, during periods of prolonged drought therewill not be enough water for all the users. Even now, the quantity of water that Isdiverted plus evapo- transpiration losses from the reservoirs andriver bottoms is approaching

1.Lee Ferry is a point in the mainstream of theColorado River one mile below themouth of Paria River.It is the dividing point between the Upper and the Lower Basins. 10 the amount of water that flows in the river.This means that no water is available for development, and eventually there will be a shortage of water. Another cause for water shortage that should be borne in mind is that, because of large development projects in the Upper Basin, it is expected that within 30 years no more than 8,000,000 acre-feet will be available for the Lower Basin and Mexico.This figure contrasts with the 11,800,000 acre-feet currently available (Hill, 1965).

Gila River Besides the Colorado, there is another river in this area which at one time maintained high flow into the Colorado Riverthat has since diminished.This is the Gila River. The watershed of the Gila River system is about 57, 500 square miles excluding all closed basins upstream (Arizona Water Quality Control Council, 1967). The Gila River has its source near theBlack Range in New Mexico, whence it flows westward intoArizona, entering the state near Duncan.It is joined by several tributaries including the San Francisco River, Eagle Creek, and the SanSimon, San Carlos, San Pedro, and Santa Cruz rivers.Finally, it is joined by the Salt River system west of Leveen. The Salt River system,which includes the Salt and the Verde rivers and their tributaries,supplies very little water to 11 the Gila River because much of the water is used upstream(Arizona Water Quality Control Council, 1967). The Gila River drains the southern half of Arizona and joins the Colorado River in the vicinity of Yuma, Arizona. The Gila River formerly supported irrigation in its lower reaches and contributed considerably to the flow of the lower ColoradoRiver. Now, however, the water in the river is completelyappropriated, in some sections even over--appropriated.Furthermore, the flow of the Gila River is well controlled by a series of damsand reservoirs, the first of which, Roosevelt Dam, was constructed in 1911.Consequently, practically no water is allowed to discharge intothe Colorado River.Only in unusual floods, like the ones of 1941 and 1965,has the contribution of the Gila River to the lower Colorado Riverbeen substantial. CHAPTER 3

THE DAMS

The area included in this study is defined as being bounded on the north by the Imperial Dam. Downstream from the Imperial Dam,there are two other dams on the Colorado River - the LagunaDiversion Dam and

Morelos Dam.

Imperial Dam At the northern end of the area under study isthe Imperial Dam (Figures 2, 3).The Imperial Dam and the Desilting Works arelocated on the Colorado River 18 miles northeastof Yuma, Arizona. The dam created a lake of 85,000acre-foot capacity.It was not built as a storage dam, and its storage capacity hasdecreased with silting.The dam was designed to pass an assumed maximumflood of 180,000 cubic feet per second2 (United States Bureau of Reclamation, 1961). Water for irrigation is diverted atthe Imperial Dam into the All American Canal to the westand into the Gila Gravity MainCanal to the east.

2.Referred to hereafter as "cfs."

12 13

- ______

Figure 2 - Imperial Dam

Looking Northward with All American Canal inForeground 14

Figure 3 - Desilting Works atthe Head of the All American Canal 15

The All American Canal facilities (Figure 4) can divert 15, 155 cfs.The canal serves the Imperial and Coachella valleys in southern California, the Yuma Project in California and Arizona, and the city of Yuma, Arizona. There is also a provision for delivery of water to Mexico. The Gila Gravity Main Canal facilities provide for a diversion of 2,200 cfs.The canal runs in a general southeasterly direction for about 21 miles.En route, water is supplied to the North Gila Valley Irrigation District.Near Fortuna, part of the water is lifted 52 feet by the Yuma Mesa Pumping Plant to an elevation of 216 feet for use on the Yuma Mesa by the Yuma Mesa Irrigation and Drainage District. The Wellton-Mohawk Canal takes water from the Gila Gravity Main Canal at a point 15 miles south of Imperial Dam, and then carries it to the Wellton-Mohawk Irrigation and Drainage District in theGila Lower Valley. The Weilton and the Mohawk canals get their water from the Wellton-Mohawk Canal near its terminus (See Figure 1).

Laquna Dam The Laguna Diversion Dam is located on theColorado River four miles downstream from the Imperial Dam.It is a rockfill weir-type dam with a structural height of 43 feet.It was constructed in 1909 to divert water for the Yuma Project in Arizona(Wilbur and Ely, 1948).It now serves only as a downstream toe protectionfor Imperial Dam (United States Bureau of Reclamation, 1961). 16

Figure 4 - All American Canal

Looking Southward fromImperial Dam 17

Morelos Dam The Morelos Dam (Figure 5) is a low weir-type diversion structure located in the limitrophe section of the Colorado River near Yuma, about one mile downstream from the international border. The Morelos Darn was built in accordance with the Treaty with Mexico of February 3, 1944. Article 12 of the treaty reads: Mexico shall construct at its expense, within a period of five years from the date of this treaty, a main diversion structure below the point where the northernmost part of the international land boundary line intersects the Colorado River. .The commission3 shall thereafter maintain and oper ate the structure at the expense of Mexico. Therefore, the structure, later named "Morelos Dam," was constructed, being completed by September 1950. By June 30, 1951, a set of rules for the operation and maintenance of the dam was adopted in what is known as "Minute197" of the International Boundary and Water Commission. It should be noted that water is no longer diverted for use by Mexico below Morelos Dam, which thus serves as the southernmost diversion structure on the Colorado River.

3.That is, the International Boundary and Water Commission. 18

Figure 5 - Moreos Dam CHAPTER 4

THE DRAIN CANALS

The Lower Basin of the Colorado River has been a major irrigated farming area for centuries.Years ago, the Gila River was a very important source of fresh water.Ruins of ancient Indian villages show that the people who inhabited them cultivated the soil, irrigated it by means of canals, and even built reservoirs to store water.In more recent times, the Lower Basin was inhabited by Pima, Maricopa and Papago Indians who also cultivated the soil with irrigation (Powell, 1895). White settlers were practicing extensive irrigation in the Weilton- Mohawk area by 1891. The source of water was the Gila Riverwhich was never entirely dependable. By 1908, upstreamdevelopment was limiting the flow. Roosevelt Dam was built in 1911 to store the water of the Salt

River.Other dams were constructed and there were additional diversions for irrigation upstream. As a result, the flow in thelower reaches of the Gila River became practically nonexistent.Consequently, by 1920, irrigation in the area had virtually ceased(Moser, 1967). About that time, exploitation of a new source - groundwater - was introduced to the area, and it became fhe major source of water supply.

19 20 Even this source, however, failed. Because of its continuous recirculation without replenishment, the water became more saline.The salinity of some wells reached the level of 6,000 parts permillion4 (United States Bureau of Reclamation, 1966).The salinity of the water caused, in turn, salinity of the soil.So once again a new source of water had to be found. This source was the major water source in the area - the Colorado

River.Diversion of the Colorado River water into the Wellton-Mohawk area was accomplished by meansof the Gila Project.Construction was begun in 1949, and by May 1952 Colorado River water wasintroduced into the area (United States Bureau of Reclamation,1961).

Wellton-Mohawk Main Outlet Drain The application of Colorado River water in the areacaused the water table to rise considerably. As a result,the drainage problem which already existed in the area, became much moreacute.Various means of alleviating the situation were studied, and it wasdecided that the best solution would be to pump the drainage waterthrough a system of wells Into a conveyance channel. This area iswell suited to well-type drainage because of itsgeological structure. Consequently, the Wellton-Mohawk MainOutlet Drain was constructed in 1961 to discharge the drainage waterinto the Gila River near

4.Referred to hereafter asItppm. 21 its confluence with the Colorado River. At the same time, 67 wells were drilled in the area of high water table.The wells were found to be very saline, ranging from 2,000 to 18,000 ppm of total dissolvedsolids.5 By July 1961, the wells were discharging to the full capacityof the canal, i.e., 300 ci s, with a composite discharge salinity of 6,500 ppm. The immediate result of this discharge was an increase in the salinity of the Colorado River and thus of the water usedby Mexico. In order to lower the composite salinity of thedischarge wells discharging into the Colorado River, supplementary waterof lower salinity was required. Hence, 26 newwells were drilled at suitable locations; by 1963, 93 wells were in operation.This provided the possibility of lowering the composite salinity to 5,800 ppm attimes when the flow of the Colorado River was small andproportionately small amounts of water were available for mixing. In order to alleviate the drainageproblems further, tile drains were installed on 8,000 acresof land. The salinity of the river water, however, still did not decreaseappreciably.

Main Outlet Drain Extension The new situation, i.e., theflow of saline water into the Colorado River, as mentioned above,created problems for the users ofthe river

5.Total Dissolved Solids is a parameterused to define he quality of water.It may be expressed asmg/liter or as ppm. 22 water.Furthermore, Mexico maintained that the quality of the water that it was receiving was unacceptable. Actually, in the Treaty of 1944 (vide infra), the United States did not makeany commitments about the quality of the water to be delivered to Mexico. Nevertheless, the problem was recognized by the United States and this led to the agreement between the countries which is known as "Minute 218" of the International Boundary and Water Commission (See Appendix A). The main concern was how to alleviate the drainage conditions in the Wellton-Mohawk area without increasing considerably the salinity of the Colorado River, and, simultaneously, to assure the delivery of the quantity of water allocated to Mexico. The result was that the Bureau of Reclamation extended the Wellton-Mohawk Main Outlet Drain to the Morelos Dam (Figures 6-8 ), an extension of about 12 miles. The channel is concrete-lined and has a capacity of 353 cfs.The official name is the "Main Outlet Drain Extension" or M.O.D.E. (United States Bureau of Reclamation, 1966). The purpose of this canal is to convey the water to a point either directly above or below the dam and to discharge it there.Since no water is taken for use from the Colorado River in the stretch from below Morelos Dam to the mouth of the river at the Gulf of California, it was thought that discharging the drain water below Morelos Dam would not entail any harm. M.O.D.E. has three discharge locations. One, M.O.D.E. No. 1, is located at the confluence of the Colorado and Gila rivers.It is used to CO. D4, 'a 04 / CO (5 I7LSY k Figure 6 - Wellton-Mohawk Drainage Conveyance Facilities (United States Bureau of Reclamation, 1966) 24

Figure 7 - Main Outlet Drain Extension 25

Figure 8 - Gate and Gage on the Main Outlet Drain Extension 26 discharge the drain water at this location only when the canal downstream is undergoing repair or maintenance operations.The other two discharge locations are located above (No. 2) and below (No. 3) Morelos Dam and are used in the daily operations (Figures 9, 10). The outlet above Morelos Dam (No. 2) was devised in order to discharge at that point all or part of the drainage water from the Weliton- Mohawk area during the period from February 11 to September 30.The salinity of the drainage water is controlled in order to minimizethe salinity of the water delivered to Mexico. The outlet below Morelos Dam (No. 3) is used duringthe period from October 1 to February 10, when all theWellton-Mohawk drainage water is discharged below the dam. Atthis time, insofar as practicable, the water is pumped from the more saline drainwells (United States Bureau of Reclamation, 1966). The canal was completed in 1965.It started carrying the drain-

age water on November16, 1965 and has been in continuousoperation ever since.

Yuma Main Drain

The Yuma Valley of Arizona hashad a definite drainage problem since the beginning of the centurywhen irrigation was firstintroduced to the area.In order to alleviate the problem,the first 22 shallow wells were constructed in 1911 to pumpthe drain water (Brown, Harshbarger, 27

Figure 9 - Main Outlet Drain Extension - Discharge Location No. 2 above Morelos Dam 28

Figure 10 - Main Outlet Drain Extension - Discharge Location No. 3 below Morelos Dam 29 and Thomas, 1956). By 1916, construction of gravity ditches had begun. From these beginnings, there developed the present day network of more than 350 drain wells and drain canals which extend to the agricultural lands where the water table has reached the critical point. The water from the various drain canals is collected into a main open drain which runs southward to the Arizona-Mexicoborder.There it is raised 12 to 15 feet by booster pumps into Mexico nearSan Luis (Figure 11). The flow is charged against the Mexican allocationof 1, 500, 000 acre-feet per year. The annual flow rangesfrom 123,400 to 135,200 acre-feet (see Table I).The quality of the water ranges between 1,500 and 1,700 ppm of TDS-(TJnited StatesGeological Survey, 1961-1965,

1966, 1967). 30

Figure 11 - Yuma Main Drain Pumping Station near San Luis CHAPTER 5

INTERSTATE AND INTERNATIONAL ASPECTS

The Colorado River is an interstate as well as international river. The Colorado River basin extends through seven states (Wyoming, Utah, Colorado, New Mexico, Arizona, Nevada, and California) and two countries (the United States and the Republic of Mexico). At the beginning of the twentieth century, the Colorado River was untapped and uncontrolled.Floods caused considerable damage, especi- ally in the lower stretches of the river.The river was not utilized as a source of power even though there is a dropof 8, 000 feet in the course of the river.

The Colorado River Compact Since the Colorado River is an interstate stream, it was realized that an interstate compact was essential.On November 24, 1922 a compact was signed by the seven statesthat comprise the Colorado River basin, i.e., Arizona, California,Colorado, Nevada, New Mexico, Utah, and Wyoming. (See Appendix B.) There were three main reasons behind the ideathat led to the

Colorado River Compact(Olson, 1926). These were: (1) the menace of

31 32 floods, (2) the need for water for agricultural and domestic use, and (3) the growing demand for power. Article III of the Colorado River Compact is most pertinent to this study.It deals with the division of water between the upper and the lower basin states.It provides for the annual diversion of 7,500,000 acre-feet of water to the Lower Basin at Lee Ferry.In addition, the Lower Basin was given the right to increase its beneficial consumptive use of such water by 1,000,000 acre-feet per annum. Arizona was the only state that objected to the Colorado River Compact, but the Legislature did ratify it eventually in 1944.Ratifi- cation was delayed primarily because of the inclusion of the Gila River as part of the Colorado River system.Arizona maintained that only the water of the mainstream of the Colorado Rivershould be apportioned among the states.That contention was upheld by the United States Supreme Court on June 3, 1963 in the Arizona vs.California case; the Gila River water was reserved for Arizonaand not included in the Colo- rado River water allocations(Mann, 1963).

'flBoulder Canyon Project Act On December 21, 1928, theSeventieth Congress passed the

Boulder Canyon Project Act.The purpose of the act, as stated, was: Controlling the floods, improving navigationand regulating the flow of the Colorado River,providing for storage and for the delivery of stored waterthereof for reclamation of public lands 33

and other beneficial uses exclusively in the United States and for generation of electrical energy as a means of making the project herein authorized a self-supporting and financially solvent under- taking. The Secretary of the Interior, subject to the terms of the ColoradoRiver Compact, was authorized 'to construct, operate, and maintain adam and incidental work in the mainstream of the Colorado Riverat Black Canyon or Boulder Canyon." Section 4 of this act suggests apportionmentof the 7, 500,000 acre-feet of water allocated to the Lower Basinstates as follows: to California,4,400,000 acre-feet to Arizona, 2,800,000 acre-feet to Nevada, 300,000 acre-feet Arizona fought this act alsobut could not prevent its passageby Congress. All the statesconcerned ratified the act except Arizona.By

1944, however, Arizonahad negotiated a contract withthe Secretary of the Interior for the 2 , 800,000 acre-feet of Colorado Riverwater apportioned to it.This agreement wasratified by the Arizona Legislature even before theColorado River Compact(which was ratified immediately thereafter).In 1944, therefore,the apportionment of the water of the Colorado River amongthe Lower Basin states as provided by the Boulder Canyon ProjectAct became effective. 34

The 1944 Treaty between the United States of America and the Republic of Mexico

As was mentioned previously, the Colorado River flows intothe Gulf of California at a point which is 80 miles south of theinternational border between the United States and Mexico. Thedisputes between the two countries over the Colorado River waterhave b een many and prolonged during the last century.There had also been disputes over twoother international streams - the RioGrande and the Tijuana. On February 3, 1944, a treaty wassigned by the United States and Mexico. This treaty isconcerned with the utilizationof the waters of the three rivers - theColorado, the Rio Grande, theTijuana. Articles 10 through 15 of SectionIII of the treaty pertain to the Colorado River. Some of theprovisions of the treaty are asfollows. Mexico is to receive1,500,000 acre-feet annually.In the event of excess flow in any year,the United States willdeliver 1,700,000 acre- feet, although Mexicohas no rights in excessof 1,500,000 acre-feet. In the event of alack of water in theColorado River, Mexico will receive less water in the sameproportion as the decrease inconsumptive use in the United States.Furthermore, from the timeDavis Dam (upstream from Imperial Dam) isin operation until January1, 1980, the United States will deliverannually to Mexico, in thelimitrophe section of the river, 1,000,000acre-feet of water, and afterwards1,125,000 acre-feet. 35

Similarly, 500,000 and 375,000 acre-feet, before and after January 1, 1980 respectively, will be delivered at the international boundary by means of the All American Canal. Mexico will pay proportionatelyfor the cost of the Imperial Dam and of the Imperial Dam - Pilot Knob section of the All American Canal. This treaty made no mention of water quality. When thequality of the river water deteriorated (see Chapter 8), Mexicocomplained although no official complaint could be based onthe treaty.It was recognized, nevertheless, that the quality of thewater delivered to Mexico had worsened. The executiveagreement known as Minute 218 (Appendix A) was adopted in order to remedythe situation. Since the treaty wassigned, Mexico has been receivingits allocation of water, and therehave been no further disputesin regard to water quantities. CHAPTER 6

WATER BALANCE

The Colorado River,as the main supplier of water and as the major drain channel of the area, hasmany incoming and outgoing flows. The water balance of the flows of the Colorado Riverbetween Imperial and Morelos dams was computed in order to evaluate the water budget. "Water Resources Dat&' for Arizona (1960-1965) and for California (1966), published by the United States Geological Survey, servedas the source of the data.The computations for 1960 to 1965 were based on the Arizona data.California data were used for the 1966 computations because the extension of the Wellton-Mohawk Main Outlet Drain entered into operation in 1965 and the new gaging stations began functioning in

1966.The 1966 report for Arizona had not yet been published at the time of the writing of this report. The water budget took into consideration all the flows into and out of the river which were gaged and recorded by the three agencies - the United States Geological Survey, the United States Bureau of Recla- mation, and the International Boundary and Water Commission. The major diversion occurs at Imperial Dam (Figure 12, gaging station no. 4295) where water is diverted into the All American Canal and

36 AlIAmencan Canal 5275 05270 5265 5240 AllAranricOn Canal Alamo Cons? a Dram 88 CnnAllAmericanfor Station Canal divcrsins 5240 from Main Drain No.4 G 5) 5230 a 5305 5300 and Yurna Main Canal Pass rant ion 5.) + 5222 GOtORADO RIVER 5325 A 5220ow Yama Main CanaIY5250 wasloway.._4 5255 5294 C0L0AD0 p95288 RIVER LACUNA DAM? IMPERIAL DAM 4295 is330 a 95320 E I c r* 5292.5 5290 Levan waslawoy Canal La9uaa Canal wosInway 0 West Main Ui5) Canal Cooper Canal 4 t \ O 0--s292 5291.5 5225 \ n.5 <-J o LNOr?h Gila Drain No.1 5340 Main drain Canal \ \ 529! i i3 North Gila Canal A 5345 East Main Canal A Canal Ia p <-0. 5290.5 Gravit Main Canal EXPLANATIONGaqinq 0 5286 station Oszos between Imperial Dam and the Southern International Boundary, Figure 12 - Schematic Diagram Showing Gaging Stations (United States Geological Survey, 1965) 1960-1965 38 into the Gila Gravity Main Canal (gaging stations 5230 and 5225 respectively).The remaining water flows down the river channel. Since 1960, when the city of Yuma, Arizona ceased pumping water from the / Colorado River, there has been no diversion of water within the United States from the Colorado River below Imperial Dam. Mexico, however, receives the major portion of its water allocation at the Morelos Di- version Dam. Various flows discharge into the Colorado River.For some time, a major contributor of fresh water was theGila River (gaging station 5205). The Gila River was no longer a source, however, once its water had been appropriated and the flow had beencontrolled by a series of dams and reservoirs. At present, the only source consistsof the drain canals and wasteways. Some of the draincanals are relatively small with small discharge whereas others areof large size with rather sizable flows. The All American Canalsupplies water to the Yuma Project Reser- vation Division for irrigationand also to the Pilot Knob hydroelectric station. These two usersreturn large amounts of water back into the channel, as drainage water(Reservation Main Drain no. 4, gaging station 5300) and wastewater (Pilot Knob Wasteway, gaging station 5270) respectively. Anotherlarge source of waste water in the western section is the Yuma MainCanal (gaging station 5250). 39

Until 1965, the main dischargeon the eastern side of the Colorado River consisted of water from theWellton-Mohawk Main Out- let Drain which discharged its entire flow into theGila channel (gaging

station 5293) through which it flowed into the Colorado River.Since 1965, the discharge has been directly into the Colorado River above and below Morelos Dam where two Parshall flumes were constructed to measure the flow (gaging stations 5318 and 5319; see Figure 13). As a result of this change, the flows for 1966 had to be computed on a basis different from that used for the previous years. The Colorado River flows of each year were totaled from the flows recorded at the individual gaging stations.These figures were then com- pared with the flows recorded at the downstream gaging stations numbers 5220 (Northern International Boundary above Morelos Dam) and 5222 (Southern International Boundary at San Luis).Invariably, the computed flows were smaller than the gaged flows (Table I, rows 27 and 28). This discrepancy (Table I, row 29) varied greatly over the years, from a minimum of 42,414 acre-feet in 1965 to a maximum of 76,064 acre- feet in 1961.Furthermore, there is also a difference, although very small, between the measured and the computed flows below Imperial Dam (Table I, rows 4 and 5).

These discrepancies can be attributed to two main factors.The first and probably principal factor is that the river acts as a drain. All-American Canal 5275 5236 05236 05234 05232 AllAmerican Canal 052701Y (LS3O4 C)-'--I. 5239 5240 C 5.-C) Y V (3 C, Alamo Canal 'Drain 66 5245 (3 5299 298 Main _j 5296 Drain - 0 95305t 5300 cx 5230 5222 COLORADO RIVER 5220 Ynma Main Canal1" 5250 wosleway__.4 5211 COLORADOA RIVER LAG lJ N A DA 5286 IMPERIAL DAM 0 53256 p5320 a ó2ô 0)h1n Qjllet 0) 0) drain extension 5255 E a --1 x 5292.5 52909 i 95288 Levee Canal La9ona Canal wastewoy West Main Canal Cooper Conal >- - cjr- 529l5 0-- waslewoy 5225 534,' Main drain _I 8 Canal o -j <-0 LNOrth Gil North GIla Main Drain No.1 I-, 5345 East Main Canal I,' I 5290.5 Unit B Main Canal 5229 A Canal 5228 5228.5 °529l 593 I Gila Gravit5226 Main Canal I 5205 EXPLANATIONGoqin6 0 5266 station 5,15 5227 between Imperial Dam and the Southern International Boundary,Figure 1966 13 (United States Geological Survey, 1966)Schematic Diagram Showing Gaging Stations TABLE I Raw Gaging Description Water Budget°1960 1 1961 1962 1963 196-4 1965 1966 No. Station 1 4295 Flow above Imperial Dam 7,338,000 6,527,000 6,220,000 6,612,000 6,076,000 5,776,000 5,770,000 5432 52305225 Flow into theAllGila Americanriver Main (computed) Canal Canal 582,500798 900 5,218,000 803 800 4,970,000 382,400867 600 5,104,000 587,700596,900920 030 4,635,000 541541,700899 900300 4,604,000 282282,800879 600200 4,601,000 321320,300855 000700 876 528852865290 NorthLeveeLogunaFlow into CanalGila Canal the Drain Wastewoyriver Wastewoy No.(measured) 1 :19,820 7,5009,780 382,000 13,820 7,1605,610 18,180 7,7707,010 11,9007,8504,970 7,6209,7101,130 7,1405,6-40 613 10 9 5290.55205 NorthGila River Gila Drain No. 3 10,240 18,650 3,450 7,760 906 1,010 207 -799279 619 11 5291 Fortuna Wostewoy , 396 502 845 1,150 1,300 14131215 52925291.65291.55292.5 SouthNorthBruce GilaGilo Church Main pump CanalWastewoyDrain outlet Wasteway No. 3 9,3005,760 10,8809,170 362 8,8309,360 723 6,8906,630 725 5,5908,5705,930 723 13,080 2,6805,900 712 16 - 94,930 205,300 218,800 180,000 174,700 209,700 191817 529352945293.65293.3 SouthWelltonSouth Gila Mohawk Gila pumppump Drain Canal outletoutlet No.2 Na. No. 1 2 2,6501,080 27,62017,640 311 30,22028,310 24,37013,400 28,26020,380 515 29,10019,200 I 212022 5294.45294.25250 YumoSouth MainGilaGila TerminalpumpCanal outletWosteway Wastewoy No. 4 533,600 79,830 123,500 93,370 135,300 1,510 . 106,400 5,5801,080 26252423 527053055300 ReservationTotoPilotDrain Knob 8 B Main Power Drain Plant No. & Wastewa4 addition to river 794 500 1,251,806 496 40046,950 4,990 1,162,535 729 30047,120 4,460 1,277,735 765 200 46,0304,290 1,001,602 600 700 4-6,080 3,500 1,125,986 68-4,800 39,360 2,660 1,201,514 752 700 38,670 1,400 282729 5220 InternationalComputed flow Boundary (row 26 (measured)+ row 5) 1,760,1061 836 17076,064 1,544,5351 599 000 54,465 1,874,6351 941 000 66,365 1,617,0001,543,502 73,498 11,411,586 454 000 42,414 1,522,5141 511 00-0 62,905° 323130 53195318 . 4.14 3.41 3.41 4.55 2.92 7495,040 420 4.16 13.433 533053255320 21-mile11-mileCooper". . S WastewnyWasteway Wasty I 18,120 7,9302,000 15,610 64401,340 15,370 81,770 430 10,0906 6001,630 35,170 1801,130 23,7501,090 350 3736 5222 FlowColoradoTotal +to row Alamo River 213 Canal(near San(computed) Luis) row 36 - row 37 1,587,7491,864,220 276,471135,200 1,391,9901,622,390 230,400131,600 1,966,5701,627,770 338,800135,100 1,566,6801,635,320 136,50068,640 1,398,4101,463,480 130,80065,070 11,518,190 ,3B,390 123,400149,800 403938 53455340 ° Figures taken from the United States Geological Survey TotalMainEast Drainin Main (near CanalDrain San Wasteway Luis 145,41010,210 145,06013,460 b In order to achieve uniformity, the measuremenf of station 149,700 14,700 145,980 9,480 135,360 4,560 128,360 4,960 (1960- 1966) differencestation5319 (established -5220. = 1,585,420- Hence, in 1966) 1 ,5l 1,522,514must 1,000 be +added 74,420 = 62,906. to measured 1 585,420; 42

Many drainage flows from local irrigation districts find their way into the Colorado River without being measured. Another factor is the error which is inherent in the measurement itself.Furthermore, different gaging methods are employed by the various agencies. Three agencies, for example, are involved in measuring the flow in the Wellton-Mohawk Main Outlet Drain and its extension; these are the United States Geological Survey at the head of the canal (gaging station no.5293), the Bureau of Reclamation at gaging station no. 5318,and the Inter- national Boundary and Water Commission at gaging station no.5319. The discrepancy which can be attributed to this typeof error is probably minor. It should be noted that, althoughthe quantity of water involved is impressive, the discrepancy isactually quite small as a percentage of the total flow.Thus, the discrepancy at thedownstream gaging stations ranges from 2.92% in1965 to 4.55% in 1964. The water budget also showsthat the Republic of Mexico received more than its allocatedshare of 1, 500, 000 acre-feet of the Colorado River water in the years1961, 1963, 1964, and 1965.

The City of Yuma The only major urban communitywithin the area under study is Yuma, Arizona. At present,Yuma receives its water from the All Ameri- can Canal by meansof the Yuma Irrigation District facilities.During 43 the 12-month period ending November 30,1967, the city used 3,034,471,000 gallons of water, which is about9,300 acre-feet (Arizona Water Company, 1967). Of thisamount, 2, 930, 762, 000 gal- ions (about 9,000 acre-feet) were sold to the approximately9,300 customers. As these figures show, the consumption for domestic and industrial uses is rather small in comparison with that for agricultural use. Thus, the forfner are of small importance in the water budget. However, the domestic use is very important in considerations of water quality and water cost. These aspects are discussed below (Chapters 8 and 9). CHAPTER 7

GROUNDWATER

Groundwater constitutes another source of water in the studied area. Indeed, for many years groundwater had been the only source of supply for water in the Wellton-Mohawk area.Then, as mentioned above, Colorado River water was diverted to this area because of the salinity problems. Groundwater no longer supplies a major portion of the fresh water used for irrigation.Nevertheless, some attention should be devoted to the groundwater conditions in the area. The geological features of the Yuma area are as follows (Olmsted and McDonald, 1967):(1) a basement complex of pre- Tertiary age, (2) nothinal sedimentary rock and volcanicrocks of Terti- ary age, (3) marine depositsfrom the Tertiary period, and (4) alluvium of late Tertiary and Quaternary age. Thefirst two form mountains and parts of the Piedmont areas andunderlie the latter two beneath the valleys and mesas. Most of the usable groundwaterin the area is contained in the alluvium formations. The alluvium consistspredominantly of deposits of the Colorado and Gila rivers, but it alsoincludes detritus of local origin.The most abundant material is sand of fine to medium grain 44 45 which was deposited by the rivers, hut some gravel is present also. Including the marine deposits, the alluvium extends to a depth of more than 3,000 feet in the southwestern part of the area, but to less than 500 feet near the mountains in the northeast (Figure 14). Most of the alluvium in the area contains fresh water with less than 1,800 ppm of dissolved solids at depths ranging from 200 feet at Laguna Dam to 2,900 feet at San Luis.The main source of recharge is the deeply percolating water from the Colorado River and seepage from canals and laterals. Application of irrigation water to the sandy soils on the Yuma Mesa also has a great effect on the groundwater.It created a groundwater mound which changed the regional flow patternsand increased storage to about 1,750,000 acre-feet asof 1965 (Olmsted and McDonald, 1967). There is a large fault which extendssoutheasterly across the Yuma Mesa and the Upper Mesa. Thisfault is mostly concealed by unaffected younger alluvial deposits.Recently discovered evidence (Olmsted and McDonald, 1967) indicatesthat this fault operates as a barrier, affectingthe southern movement of thegroundwater. The groundwater mound in this area islocated north of the fault.Because of the barrier, the flow of the waterfrom the mound is diverted toward the southeast along the faultwhich impedes the flow of groundwater to 46

---"00-----lXPl./.tlAilO / Iflflpfih S1oflw tI,klno0 01 nUov Ion,, trnr,nIlIfln noon 01 n,,d TrtI,ry nfl nr Inn ,ijn0o. t0.xninod .,hnro poorly co,,iroIlo [Ti TnrtInry or prr-TrnI!ory rok,

1).nnhrd v;Iiorr UflCOrtZflIfl, olIed ohoro coocondod. fl,Alloviol roonry,onnt

, _\ nb \\ 0 \\ \\\ \\ \ \'\ \ \\' \\ n iç ,,i \"\\\, U \\ .A \\ 0 0

I o 0 ', \ - ) C.... \ 0 \\ -- N

Figure 14 Map of the Yuma AreaShowing Thickness of Alluvium (Olmsted and McDonald,1967) 47

Mexico (Figure 15).As a result, in recent years the average rate of rise of the water table northeast of the fault has been three times that in the area southwest of the fault.The maximum vertical displacement of the water table across the fault exceeds 30 feet. The United States Geological Survey is presently conducting studies of the groundwater in the area. An analogue model is being designed which will determine the groundwater characteristics of the area.This model will predict groundwater conditions, and thus, once it is in operation, should serve as an important tool in future studies. 48

ELArtA1t0N 40--- Wator tutoto contour stone ltttndo ot u.utur thlo. Dunked whoru porty ocjitruflv& Cuotcor I tervt 10 foot. tthm In Dlccn 000 level. LTI] Tent ary end pro-T ertlury rocks

Fault Dashed where unoerta in dettod where ounce sled

>0 Alluvial 000atpooent

qifr

/tIJ0,RC. - \ 80'< \____

Figure 15 Map of the Yuma Area Showing Configuration of the Water Table, 1965 (Olmsted and McDonald1 1967) CHAPTER 8

WATER QUALITY

The quality and the quantity of the water in the Colorado River are definitely interrelated.Generally, the higher the flow, the lower the concentration of Total Dissolved Solids (TDS).In the years before man began tampering with the Colorado River, the concentration of salts in the water depended mainly on the flow of the river which varied annually and seasonally. The salinity conditions changed drastically for the worse with the new developments in the region.Several reasons for this can be cited. The dams and reservoirs control the flow so that now there are practically no natural seasonal variations. Evaporation from the reservoirs decreases the amount of water in the system. Diversion of fresh water at the headworks decreases the flow of fresh water downstream. Increase in irrigation increases the quantity of highsalin- ity drainage water which flows into the river. These as well as other factors increase the salinity of theriver water. The farther south, the higher the salt concentration.

49 50

The first data on the salinity of the Colorado River were collected more than 60 years ago.Systematic records, however, have been kept only since 1925 (Olmsted andMcDonald, 1967). Recent records show substantial increases in TDS at LeeFerry, below Hoover Dam, and at Imperial Dam due to the dischargeof drainage water into the river channel (Figure 16).In 1965, the average weighted dissolved solids at Imperial Dam was about 920 ppm,and the proposed developments in the area may increase it to morethan 1000 ppm in the very near future (Olmsted andMcDonald, 1967). As the river flows southward fromImperial Dam toward the international boundary, the quality of waterdeteriorates further because of the drain and waste waters which,discharge into the river channel. The salinity varies considerably duringthe year in this section of the river also. One of the principal causes ofincreased salinity of the Colorado

River was the Wellton-MohawkMain Outlet Drain when its waterdis- charged regularly into the GilaRiver and thence into the Colorado

River.As mentioned above (see alsoAppendix A), Mexico complained and consequently the MainOutlet Drain Extension wasconstructed. Thereafter, the flow from the draincanal could be discharged either above or below the Morelos Dam.When the water is discharged above Morelos Dam, it, of course, increasesthe salinity of the Colorado 51

110 i:ii_tiiJ__. -

100 __i_

At Imperial Darn

90 1 Below Hoover Darn 60 .I ppp

.'-1 !

' 70 rd 0 gi 0 H H + 0 H 50 I1iIIL111Ii'11ii_At Lee Ferry

140 .'iI 53 5 Year

Figure 16 - Yearly Weighted Average TotalDissolved Solids at Critical Points in the Colorado River Data for 1965 and 1966 are provisional. (Arizona Water Quality Control Council, 1967) 52

River considerably. On the other hand, there is a possibility that discharging the drain water below Morelos Dam pollutes the aquifer water in the area since the main source of recharge of the groundwater in this region is the flow in the channel of the Colorado River down to the Gulf of California. The Wellton--Mohawk Main Outlet Drain, as described above, is a major collector of drain water in the area.The salt content of its water is generally about 5,000 ppm (United States Bureau of Reclama- tion, 1966). The actual salt concentration is controlled by the mixing of water of different salt concentrations flowing from different wells. There are also several other drains from local irrigation areas that discharge into the Colorado River or into the Gila River.They are not controlled, and very little, if any, information is availableabout the flows and the salt concentrations of these drains. However, since these are drain canals, the concentration of salts is probably highand therefore increases the salt concentration in the Colorado River. The only city that was getting its water from the Colorado River below the Imperial Dam was Yuma, Arizona. The UnitedStates Public Health Service (1961) standard for drinking water is 250 ppmof chlorides.Therefore, when the chlorides at the point of delivery increased to as much as 2,500-3,500 ppm, primarilybecause of the Weilton- Mohawk drain canal water, Yuma had to obtain its water from another 53 source. The water is now supplied from the All American Canal by means of the Yuma Irrigation District Canal which crosses the Colorado River by siphon. Since 1960, the city receives water of 300 ppm chlo- rides1 which is above the standard but acceptable (Arizona Water Company, 1967).It should be noted that the water quality in the Yuma Main Canal is about the same as at Imperial Dam since all the water in the All American Canal originates at Imperial Dam. The original Treaty of 1944 between the United States and the Republic of Mexico allocated water from the Colorado River to Mexico but made no mention of water quality. However, the deterioration of the water quality led to a discussion of this subject by the International Boundary and Water Commission with the resultant adoption of Minute 218 (Appendix A) in 1965. Minute 218 provided for the construction of M.O.D.E. because of the effect of the Wellton-Mohawk drain canal. The Commission is to meet again in 1970 to review the salinity conditions. Because practically no water is diverted below Imperial Dam for use by or in the United States,the problem emerged as an international rather than a local matter, and that is what it is today. CHAPTER 9

WATER COST

One of the most important aspects of water is its economic value (cost).It is often heard that water is or should be a free commodity, as if it either has no usefulness or is not scarce.The fallacy inherent in this idea is by now well recognized.It is accepted that water, like any other useful and scarce resource, has its value.It may and frequently does have value in excess of the cost incurred for its pumping and delivery, and for the operation and maintenance of the hydraulic structures.In other words, the water itself, in situ, may have value.Its value may vary widely for different uses and for different quantities applied to a single use. The cost of water is the opportunity foregone to realize the value it may have had in one use by committing it to another. Whether or not it is priced, the sacrifice - this opportunity cost - will arise and must be reckoned with in the search for economic use of this scarce resource. In this study, information was gathered on the cost of the Colorado River water to the users in the various districts included in the area as well as in the major urban community - the city of Yuma, Arizona. 54 55

The agricultural users of Colorado River water below the Imperial Dam are supplied by the following units: Imperial Irrigation District Coachella Valley County, Water District Wellton-Mohawk Irrigation and Drainage District Yuma Mesa Irrigation and Drainage District North Gila Valley Irrigation District Yuma County Users' Association The information on water cost (Imperial Irrigation District, 1967; Coachella Valley County, Water District, 1967; Wellton-Mohawk Irrigation and Drainage District, 1967; Yuma Mesa Irrigation and Drain- age District, 1967; NorLh Gila Valley Irrigation District, 1967; Yuma

County Users' Association, 1967) has been compiled in Table II.The cost of water to the iisers varies considerably, and the method of assessment also differs. Some districts charge according to the quantity of water used (i.e., per acre-foot), others according to the area (i. e., per irrigatedacre). Of the three districts which charge on the basis of the quantity of water used, one district has auniform price regardless of the quantity, another district increases the cost with the increase in use, while a third decreases the cost under the same circumstances. Water CostTABLE II Cost to tityQuan- rnperial Irri- District TotalSize.(acres) AcreageIrri-gated Waterlivered(acre-ft)De- WaterTDS)(ppmQuality of ftacre-Per User ($) acrePer acre)ftUsed per(acre- WaterSourceColorado of DrainageIrrigationgationTellton_Mohawk District Dis-and 876,900 500,000 62,000 2,817,912 414,583 800-950 900 2.30 c - d 5.6 ground-GilaRiver,ColoradoRiver River, trictagegationuma District and Mesa Drain- Irri- 75,000 19,747 235,000 b 900 2.65 - l2.15 2.00 11.9 6.6 RiverColoradowater NorthCoachella GilaDistrictCountyIrrigation Valley Valley Water District 617,000 7,022 [ 59890a 315,504 52,162 - 8.50 7.45.26 RiverColorado TABLE Il--Continued District TotalSize(acres) AcreageIrri-gated WaterliveredDe-(acre-ft) TDS)WaterQuality(ppm of I ftacre-Per UserCost to ($) acrePer J acre)fttity Usedper(acre- WaterSource of ationUsers'uma Associ- County Additional acreage is irrigated with groundwater. 51,800 51,800 317,900 850-900 250e 6.1 RiverColorado AverageAssessedinCharge$1.50Charge price, annual forper inadditionwith for eachacre-foot. usage. eachmaximum of of tofirst firstquantity fourcharge five acre-feet; acre-feet;charges. of $3.40 additional peradditional acre-foot. quantities quantities vary cost 58

In reference to the effect of the cost on the use of water, the picture is not decisive and only generalizations can be made. An interesting outcome of the study is the effect of the cost of water on the amount of water used for irrigation.Of course many other factors besides cost affect the quantity of water used. Nevertheless, it is interesting to note that when the cost is based on the amount of land rather than on the amount of water, more water is used (See Table II).Furthermore, it was found that only one district (the Welitom- Mohawk Irrigation and Drainage District) encourages efficiency by charging progressively more for additional quantities of water used. Nevertheless, our information does not show that the usage of water in this district is lower than in other districts as aresult.However, it must be noted that problems of soil salinity areespecially severe in this district, and therefore, more water isrequired for irrigation. The cost of water for urban use is totally different.According

to the Arizona Water Company(1967), which is the sole supplier of water to the city of Yuma, the charges aredivided into general service and residential service.The charge for general service is $87.80 for the first acre-foot and $80.71 for eachadditional unit.For residential service, these charges are $63.08 and$56.98 respectively. These charges are high for domestiO use.Furthermore, even with these high charges, the quality of the water doesnot meet the standards 59

established by the United States Public Health Service (1961). Many residents of Yuma find the regular water unpotable and therefore drink bottled water, which of dourse raises the actual cost of the water considerably.

Cost of Groundwater It is difficult to ascribe a definite cost to groundwater for several reasons. For one, the cost of pumping depends on many factors.Furthermore, the wells are operated by private owners, many of whom do not compute the cost. Others do, but are unwilling to divulge the costs and/or the amount of pumpage.Consequently, the information on the cost of groundwater appearing in this paper had to be based on data published previously, even though these figures were very general. Groundwater is reported (Arizona Interstate Stream Commission, 1967) to cost $3.00 per acre-foot for pumping lifts of 10 to 40 feet, and $20.00 for lifts of 350 to 400 feet. These costs include amortization of investment, interest, taxes, and operation and maintenance expenses. The cost of lifting one acre-foot of water one foot isreported to be about 2. 5 cents and 3. 2 cents for electric- andgas-powered pumps respectively (Nelson and Busch, 1967). 60

In the Lower Basin of the Colorado River, water is still considered to be a free commodity in situ. As was shown, however, there is a rather large difference between the costs of groundwater and of surface stream water.It is the cost of pumping the groundwater that accounts for its relatively high price. CHAPTER 10

DISCUSSION

In the previous chapters, the area downstream from the Imperial Dam on the Colorado River was described.Data were collected and evaluated in order to delineate the conditions.In addition, the existing conditions were occasionally correlated with probable future developments. Two major interrelated problems became apparent during the course of this study. These are: the limited quantity of water flowing at present in the Colorado River coupled with a foreseen shortage in the near future, a deterioration of the quality of the waterin the area due to the increased salinity of the Colorado River water flowing into the area, and also to the pollution of the water locally through the drainage canals. Of the utmost importance is theproblem of the shortage of water that will undoubtedly developwithin the next thirty years.It is now well established thatthe flow of the Colorado River at Lee Ferry -

61 62 that at times was thought to be 17,000,000 acre-feet annually- is actually less than 14,000,000 acre-feet.Studies made by Herman Stabler, Chief of the Land Classification Branch of the United States Geological Survey, demonstrated that, under the conditions of development in 1922, the mean flow of the Colorado River at Laguna Dam for the period 1878-1922 was between 13,000,000 and 14,000,000 acre- feet.Furthermore, he showed that the average flow for 20-year periods might be less than 11,000,000 acre-feet (Kelly, 1925). Hence, even at the time the Colorado River Compact was signed, the designated quantities of water could not really be guaranteed. Even though the Lower Basin states have been assured of 7,500,000 acre-feet per annum, some engineers (e.g. Hill, 1965) doubt if more than 8, 000, 000 acre-feet will be available in the future for the entire Lower Basin, and from this amount Mexico must receive 1,500,000 acre-feet in accordance with the Treaty of 1944.This shortage will result primarily from developments in the Upper Basin. At the time that less water will be available, the Lower Basin states will be needing more water to accommodatedevelopment, es- pecially of Arizona and California.Therefore, a shortage of water in the near future (within thirtyyears) seems certain. The second major problem is water quality. With the development of hydraulic projects which entail the diversionof more fresh 63 water upstream, the quality of the water in the lower reaches of the Colorado River constantly deteriorates.The forecast is for even further deterioration which will result from a greater utilization of the river water and from an increase in the discharge of drainage water into the Colorado River channel. The deterioration in quality causes serious problems for all the water users in the entire Lower Basin. These include the agricultural, the urban, and, to some extent, the industrial users.(It does not greatly affect the water used by industry for cooling purposes.) Even now, the quality of water available to the users in the area understudy is marginal (800-950 ppm of TDS). With any increase in the salt concentration at Imperial Dam, the entire water supply from the Colorado River to California and Arizona will be of a quality that may cause serious consequences. The city of Yuma, for example, might have to seek another source for its water supply, or some purificationof the water may be necessary in order to meetthe standards of the United States Public Health Service.The consequences may be equally grave for the users in Arizona and Californiaof water from the All American Canal as viell as for the users of waterfrom the Gila Gravity Main

Canal in Arizona. There are also international implications to thequality of water.As mentioned previously, the quality of water was the cause 64 of the most recent disagreement with the Republic of Mexico about the

Colorado River.It could very well be the cause of future frictionas well. As explained above, the extension of the Wellton-Mohawk Out- let Drain discharges its drain water either above or below Morelos Dam. When the water is discharged below the dam, the water Mexico receives for its use is free from the drainage water. However, the water from the

Colorado River is the source of groundwater recharge in the area.The flow of the drainage water is practically undiluted in the Colorado River channel because of the control of fresh water upstream. As a consequence, for all practical purposes the groundwater is being re- charged with drain water.This may create a problem of a different nature. It is interesting that while the area may suffer from a shorLage of usable water, there may actually be ample water of poor quality that no one wants and that is justwasted.Thus, in reality the main problem of the area may be how to dispose of this drainage water. Furthermore, it may turn out that the extension of the Wellton-Mohawk Outlet Drain was a temporary remedy at best. These then are the principal problems confronting the Lower

Basin of the Colorado River.Sooner or later, measures will have to be taken toward solving them. CHAPTER 11

CONCLUSIONS

An adequate supply of good quality water isessential for

maintaining the existing conditions and for further growthand development of the area of the lower Colorado River.Furthermore, the good

quality of the water flowing down the channel of the ColoradoRiver into Morelos Dam is a basis for good international relations with Mexico. What should be done to achieve this? There is no easy way of improving management practices at present. There are, though, possible alternatives that one can hypo- thesize. However, thorough and comprehensive study is needed in order to verify the soundness of each alternative. The complexity of the problem is apparent.It is really a dicho- tomous problem:(1) to supply water of acceptable quality to the different users, and (2) to dispose of large quantities of drainage water of rather poor quality. Can these two aspects be combined? Can one solution be found for the two problems?In other words, can the available supply of water (that no one wants) be transformed into the needed water of good

65 66 quality?If so, what system should be used and whatwould the cost be? Such a solution appears to be logical,providing, of course, that it is both technologically and economically feasible.Needless to say, it would have to be thoroughly investigated.

Other alternatives would entail the importationof water from different sources (such as from the Columbia Riveror from a desalin- ation plant at the Gulf of California)or the supplementation of the existing water supply with groundwater. Any study must be comprehensive in the sense that all the various aspects of water resources should be evaluated. Some of these aspects are obvious. One such is the economic aspect because of the cost of water of various qualities for the various users (agricultural, industrial, domestic). Another is the political aspect since the federal government, at least three states, and two countries are involved. Yet another is the legal because of the different water laws and administra- tive institutions dealing with water in each of the states and the countries. The socio-economic aspects should be considered when the effects of water and of water quality on communities and their development are studied. Hydrology and engineering will enter into all considerations of the scientific and technical aspects of each of the alternatives. 67

Time is also a factor since no long-range project wouldbe of use if a remedy were required immediately.

Other aspects of the problem cannot be foreseen.They may emerge only during the course of the study, but, nevertheless,they should not be ignored since theymay be of great value in the framework of the entire study.

Thus, the problem is of wide scope and great depth.These characteristics constitute both strength as wellas weakness. Un- doubtedly, the problem of water supply for thearea of the lower Colorado River presents a real challenge to the water resources planner. He must present an alternative or set of alternatives for better water resources management in the area. APPENDIX A

(English text of Minute 218 dated March 22, 1965)

INTERNATIONAL BOUNDARY AND WATER COMMISSION UNITED STATES AND MEXICO Ciudad Jurez, Chihuahua, March 22, 1965. Minute No. 218

RECOMMENDATIONS ON THE COLORADO RIVER SALINITY PROBLEM

The Commission met in the offices of the Mexican Section in Ciudad Jurez, Chihuahua, at 12:00 m. on March 22, 1965, to comply with instructions it has received from the two Governments, to consider measures 'to reach a permanent and effective solution1 of the problem of the salinity of the waters of the Colorado River which reach Mexico, as contemplated in the Presidential Communiques of March 16 and June 30, 1962 and February 22, 1964. The Commission reviewed the measures which the two Govern- ments have taken to date to alleviate temporarily theproblem of salinity of waters of the lower Colorado River, and noted the reductionwhich has occurred in the salinity of drainage waters from the Wellton-Mohawk Irrigation and Drainage District and that continued improvement is anticipated. The Commission, with the scientific and engineeringstudies made by both Governments as a basis, thereuponadopted the following Resolution, subject to the approval of the twoGovernments, embodying the following

Recommendations:

1. That the United States construct at its expense anexten- sion to the present Wellton-Mohawk District'sdrainage conveyance channel, with capacityof 353 cubic feet (10 cubic meters) per second, along the left bank of the 68 69

Colorado River to a point below Morelos Dam, and a control structure in that extension of the channel in the reach between Morelos Dam and the mouth of the Araz Drain, which structure would permit the discharge of the Wellton-Mohawk District' s drainage waters to the bed of the river at a point either aboveor below Morelos Dam. That the Commission permit execution of the works which may be required for the extension channel to pass through Morelos Dam. That the extension channel and control structure proposed in Recommendation 1 be operated and maintained by the United States at its expense to discharge all of the Wellton- Mohawk District's drainage waters below Morelos Dam, except those which are discharged above the Dam on the days and at such rates as Mexico may request in writing. That during the life of the present Minute and subject to the reservations of Recommendation 11, the Commission account for Wellton-Mohawk District's drainage waters as a part of those described in the provisions of Article 10 of the Water Treaty of February 3, 1944, with the understanding:a) that on the days for which Mexico requests water at the minimum winter rate of deliveries of 900 cubic feet (25.5cubic meters) per second, the United States control waters reaching the limitrophe section of the Colorado River so that without including Wellt on-Mohawk District' s drainage waters, their flows be not less than800cubic feet(22. 7cubic meters) per second, their average flow be not less than 900 cubic feet(25.5cubic meters) per second for the total of such days during each winter period for which the minimum rate is requested, and that the compu- tation of that average flow not take into account flows in excess of 1000 cubic feet(28.3cubic meters) per second; and b) that the winter periods in reference extend from October 1 of each year through February of the next following year. That throughout the life of this Minute, Mexico schedule water at the minimum rate of deliveries of 900 cubic feet (25.5cubic meters) per second, for the maximum practical number of days during each winter period, and for not less than 90 days. 70

That the pumping of Wellton-Mohawk District' s drainage waters which are to be delivered to Mexico above Morelos Dam be coordinated, insofar as practicable, with Mexico's scheduled deliveries of water at the northerly boundary in order to minimize the salinity of these deliveries; with the understanding that during the period October 1 to February 10 the United States pump at the maximum rate but not to exceed 353 cubic feet (10 cubic meters) per second and, insofar as practicable from the more saline wells in the District, and also during other periods when the total quantity of the Wellton-Mohawk District's drainage waters is discharged below Morelos Dam. That the United States endeavor to conclude arrangements to permit discontinuance of discharge of waters from the canal wasteways of the Yuma County Water Users1 Association to the bed of the Colorado River below Morelos Dam, and if necessary for this purpose, construct and operate, at the expense of the United States, works needed so that such waters be delivered near San Luis, Arizona, and San Luis, Sonora; that Mexico pay for the increased cost of pumping which may be required to discharge these waters to Mexico at the delivery point near San Luis, Arizona, and San Luis, Sonora. That this Minute be in effect during a period of five years, beginning on the date on which the extension to the Weilton- Mohawk District's drainage conveyance channel is placed in operation; and that during this period the Commission review conditions which gave rise to the problem and indue time recommend whether, in keeping with the purpose expressed by both Governments of achieving a permanentand effective solution, a new Minute should beadopted to become effective upon termination of thisperiod. That construction by the United Statesof works contemplated in this Minute be completed and theworks be placed in operation by October 1,1965, subject to the appropriation of funds by the United States Congress toimplement this Minute. That this Minute be specifically approved byboth Govern- ments. 71

11.That the provisions of this Minute not constitue any precedent, recognition, or acceptance affecting the rights of either country, with respect to the Water Treaty of February 3, 1944, and the general principles of law. The meeting then adjourned.

(Signed )j. F. Friedkin (Signed) D. Herrera J. Commissioner of the United States Commissioner of Mexico

(Signed) Louis F. Blanchard (Signed) Fernando Rivas S. Secretary of the United States SectionSecretary of the Mexican Section APPENDIX B

TEXT OF COMPACT

No. 6241 UNITED STATES OF AMERICA DEPARTMENT OF STATE To all to whom these presents shall come, greeting: I certify that the document annexed is a true copy of theColorado River compact," signed November 24, 1922, at the city of Santa Fe, N. Mex., the original of which is on file in this department. In testimony whereof I, Charles E. Hughes, Secretary of State, have hereunto caused the seal of the Department of State to be affixed and my name subscribed by the chief clerk of the said department, at the city of Washington, this 22d day of December, 1922.

CHARLES E. HUGHES, Secretary of State. (Seal.) By Ben G. Davis, Chief Clerk

COLORADO RIVER COMPACT The States of Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming, having resolved to enter into a compact under the Act of Congress of the United States of America approved August 19, 1921 (42 Statutes at Large, page 171), and the Acts of the Legislatures of the said States, have through their Governors appointed as their Commissioners: W. S. Norviel for the State of Arizona; W. F. McClure for the State of California; Deiph E. Carpenter for the State of Colorado; J. G. Scrugham for the State of Nevada; Stephen B. Davis, Jr., for the State of New Mexico; R. E. Caidwell for the State of Utah; Frank C. Emerson for the State of Wyoming; who, after negotiations participated in by Herbert Hoover, appointed by the President as the representative of the United States of America, have agreed upon the following articles:

72 73

ARTICLE I

The major purposes of this compact are to provide forthe equitable division and apportionment of theuse of the waters of the Colorado River System; to establish the relative importance of differentbeneficial uses of water; to promote interstate comity;to remove causes of present and future controversies; and tosecure the expeditious agricultural and industrial development of the Colorado River Basin,the storage of its waters, and the protection of life and property from floods.To these ends the Colorado River Basin is divided intotwo Basins, and an apportionment of the use of part of the water of the ColoradoRiver System is made to each of them with the provision that furtherequitable apportion- ments may be made.

ARTICLE II As used in this compact: The term "Colorado River System' means that portion of the Colorado River and its tributaries within the United States of America. The term "Colorado River Basin" means all of the drainage area of the Colorado River System and all other territory within the United States of America to which the waters of the Colorado River Sys- tern shall be beneficially applied. (a)The term "States of the Upper Division" means the States of Colorado, New Mexico, Utah, and Wyoming. The term "States of the Lower Division" means the States of Arizona, California, and Nevada. The term "Lee Ferry" means a point in the main stream of the Colorado River one mile below the mouth of the Paria River. The term "Upper Basin" means those parts of the States of Arizona, Colorado, New Mexico, Utah, and Wyoming within and from which waters naturally drain into the Colorado River System above Lee Ferry, and also all parts of said States located without the drainage area of the Colorado River System which are now or shall hereafter be beneficially served by waters diverted from the system above Lee Ferry. The term "Lower Basin" means those parts of the States of Arizona, California, Nevada, New Mexico, and Utah within and from which waters naturally drain into the Colorado River System below Lee Ferry, and also all parts of said States located without the drainage area of the Colorado River System which are now or shall hereafter be beneficially served by waters diverted from the system below Lee Ferry. 74

(h)The term "domestic use" shall include the use of water for household, stock, municipal, mining, milling, industrial, and other like purposes, but shall exclude the generation of electrical power.

ARTICLE III There is hereby apportioned from the Colorado River system in perpetuity to the Upper Basin and to the Lower Basin, respectively, the exclusive beneficial consumptive use of 7,500,000 acre-feet of water per annum, which shall include all water necessary for the supply of any rights which may now exist. In addition to the apportionment in paragraph (a), the Lower Basin is hereby given the right to increase its beneficial consumptive use of such waters by one million acre-feet per annum. If, as a matter of international comity, the United States of America shall hereafter recognize in the United States of Mexico any right to the use of any waters of the Colorado River System, such waters shall be supplied first from the waters which are surplus over and above the aggregate of the quantities specified in paragraphs (a) and (b); and if such surplus shall prove insufficient for this purpose, then the bur- den of such deficiency shall be equally borne by the Upper Basin and the Lower Basin, and whenever necessary the States of the Upper Division shall deliver at Lee Ferry water to supply one-half of the deficiency so recognized in addition to thatprovided in paragraph (d). The States of the Upper Division will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75,000,000 acre- feet for any period of ten consecutive years reckoned in continuing progressive series beginning with the first day of October nextsucceed- ing the ratification of this compact. The States of the Upper Division shall not withhold water, and the States of the Lower Division shall not requirethe delivery of water which can not reasonably be applied todomestic and agricultural uses. (1)Further equitable apportionment of the beneficial usesof the waters of the Colorado River Systemunapportioned by paragraphs (a), (b), and Cc) may be made in the mannerprovided in paragraph (g) at any time after October first, 1963,if and when either Basin shall have reached its total beneficial consumptive use asset out in paragraphs (a) and (b). (g)In the event of a desire for a furtherapportionment, as provided in paragraph (f), any two signatoryStates, acting through their Governors, may give joint notice ofsuch desire to the Governor of the other signatory States and to the Presidentof the United States of 75

America, and it shall be the duty of the Governors of the signatory States and of the President of the United States of America forthwith to appoint representatives, whose duty it shall be to divide and apportion equitably between the Upper Basin and Lower Basin the beneficial use of the unapportioned water of the Colorado River System, as mentioned in paragraph (f), subject to the legislative ratification of the signatory States and the Congress of the United States of America.

ARTICLE IV Inasmuch as the Colorado River has ceased to be navigable for commerce and the reservation of its waters for navigation would seriously limit the development of its basin, the use of its waters for purposes of navigation shall be subservient to the uses of such waters for domestic, agricultural, and power purposes.If the Congress shall not consent to this paragraph, the other provisions of this compact shall nevertheless remain binding. Subject to the provisions of this compact, water of the Colo- rado River System may be impounded and used for the generation of electrical power, but such impounding and use shall be subservient to the use and consumption of such water for agricultural and domestic purposes and shall not interfere with or prevent usefor such dominant purposes. The provisions of this article shall not apply to or interfere with the regulation and control by any State within its boundariesof the appropriation, use, and distribution of water.

ARTICLE V The chief official of each signatory State chargedwith the administration of water rights, together withthe Director of the United States Reclamation Service and theDirector of the United States Geo- logical Survey, shall cooperate , ex officio: To promote the systematic determinationand coordination of the facts as to flow, appropriation,consumption and use of water in the Colorado River Basin, and theinterchange of available information in such matters. To secure the ascertainment andpublication of the annual flow of the Colorado River at Lee Ferry. To perform such other duties as maybe assigned by mutual consent of the signatories from time to time. 76

ARTICLE VI Should any claim or controversy arise between any two or more of the signatory States (a) with respect to the waters of the Colorado River System not covered by the terms of this compact; (b) over the meaning or performance of any of the terms of this compact; (c) as to the allocation of the burdens incident to the performance of any article of this compact or the delivery of waters as herein provided; (d) as to the construction or operation of works within the Colorado River Basin to be situated in two or more States, or to be constructed in one State for the benefit of another State; or (e) as to the diversion of water in one State for the benefit of another State; the Governors of the States affected, upon the request of one of them, shall forthwith appoint Commissioners with power to consider and adjust such claim or controversy, subject to ratification by the Legislatures of the States so affected. Nothing herein contained shall prevent the adjustment of any such claim or controversy by any present method or by direct future legislative action of the interested States.

ARTICLE VII Nothing in this compact shall be construed as affecting theobli- gations of the United States of America to Indiantribes.

ARTICLE VIII Present perfected rights to the beneficial useof waters of the Colorado River System are unimpaired by this compact.Whenever storage capacity of 5, 000,000acre-feet shall have been provided on the main Colorado River within orfor the benefit of the Lower Basin, then claims of such rights, if any, byappropriators or users of water in the Upper Basin shall attach toand be satisfied from water that may be stored not in conflict with Article III. All other rights to the beneficial useof waters of the Colorado River System shall be satisfiedsolely from the water apportioned to that basin in which they are situate.

ARTICLE IX

Nothing in this compact shall beconstrued to limit or prevent any State from instituting or maintaining anyaction or proceeding, legal or equitable, for the protection of any right underthis compact or the enforcement of any of its provisions. 77

ARTICLE X This compact may be terminated at any time by the unanimous agreement of the signatory States.In the event of such termination all rights established under it shall continue unimpaired.

ARTICLE XI This compact shall become binding and obligatory when it shall have been approved by the Legislatures of each of the signatory States and by the Congress of the United States.Notice of approval by the Legislatures shall be given by the Governor of each signatory State to the Governors of the other signatory States and to the President of the United States, and the President of the United States is requested to give notice to the Governors of the signatory States of approval by the Congress of the United States. In witness whereof the Commissioners have signed this compact in a single original, which shall be deposited in the archives of the Department of State of the United States of America and of which a duly certified copy shall be forwarded to the Governor of each of the signatory States. Done at the City of Santa Fe, New Mexico, this twenty-fourth day of November, A. D. one thousand nine hundred and twenty-two. (Signed) W. S. Norviel. (Signed) W. F. McClure. (Signed) Deiph E. Carpenter. (Signed)J. G. Scrugham. (Signed) Stephen B. Davis, Jr. (Signed)R. E. Caidwell. (Signed) Frank C. Emerson.

Approved: (Signed) Herbert Hoover. The above copy of the Compact was made from Document No. 605, House of Representatives, Sixty-seventh Congress, Fourth Session, pp. 7-12. LIST OF REFERENCES

Arizona Interstate Stream Commission(1967) Arizona Water Resources. Arizona Water Company (1967) Personal communication. Arizona Water Quality Control Council (1967) Water QualityStandards for Streams in Arizona, State of Arizona, Department of Health, Phoenix, Arizona. Brown, R. H., Harshbarger, J. W., and Thomas, H. E.(1956) "Analysis of Basic Data Concerning Ground Water in the Yuma Area,Arizona," United States Department of the Interior, Geological Survey. Coachella Valley County, Water District(1967) Personal communication. Encyclopaedia Britannica (1964)Vol. 6, p. 92. Hely, A. G., Hughes, G. H., and Irelan, B.(1966) "Hydrologic Regi- men of Salton Sea,California," Geological Survey Professional Paper 486-C, United States GovernmentPrinting Office, Washing- ton. Hill, R. A. (1965) "Future Quantityand Quality of Colorado River Water," Journal of the Irrigationand Drainaqe Division, Pro- ceedings, American Society ofCivil Engineers, Vol. 91, No. IRl, Proc. Paper 4244, March,1965, pp. 17-30. Imperial Irrigation District(1967) Personal communication. International Boundary and WaterCommission, United States and Mexico (1960, 1961,1962) Flow of the Colorado Riverand Other Western Boundary Streamsand Related Data, WesternWater Bulletin. Kelly, W. (1925) "TheColorado River Problem,"Transactions, Ameri- can Society of CivilEngineers, Vol. 88, Proc.Paper 1558, 1925, pp. 307-347.

78 79

Kelso, M. M. (1967) "The Water-Is-Different Syndrome, or What Is Wrong with the Water Industry?" Paper presented at meeting of the American Water Resources Association, San Francisco, November 9, 1967. Mann, D. E. (1963) The Politics of Water in Arizona, University of Arizona Press, Tucson. Moser, T. H. (1967) 'Drainage by Pumped Wells in Wellton-Mohawk District," Journal of the Irriqation and Drainage Division, Ameri- can Society of Civil Engineers, Vol. 93, No. IR3, Proc. Paper 5440, September, 1967, pp. 199-208. Nelson, A. G., and Busch, C. D. (1967) "Cost of Pumping Irrigation Water in Central Arizona," Technical Bulletin 182, Arizona Agricultural Experiment Station, University of Arizona, Tucson. North Gila Valley Irrigation District (1967) Personal communication. Olmsted, F. H., and McDonald, C. C. (1967) "Hydrologic Studies of the Lower Colorado River Region," Water Resources Bulletin, American Water Resources Association, Vol. 3, No. 1, March, 1967, pp. 45-58. Olson, R. L. (1926) The Colorado River Compact, publishedby the author, Cambridge, Mass. Powell, J. W. (1895) Canyons of the Colorado, Flood and Vincent. Republished as "The Exploration of the Colorado Riverand its Canyons," Dover Publications, Inc., New York,1961. United States Bureau of Reclamation(1961) Reclamation Project Data, United States Department of the Interior,Washington.

United States Bureau of Reclamation(1966) Report on Operation of the Main Outlet Drain Extension,Minute No. w, Mexico, United States Department of theInterior, Boulder City, Nevada. United States Bureau of Reclamation(1967) Supplement No. ito Report on Operation of the MainOutlet Drain Extension, Minute No. 218 with Mexico, United StatesDepartment of the Interior, Boulder City, Nevada. 80

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