.~· . PACIFIC SOUTHWEST -vv ATER PLAN A DIGEST with COMMENTS AND SUGGESTIONS Staff: Upper Colorado Rive r Commission November 8, 1963 ( \ COLORADO RIVER N E A 0 A 0 ""' (' ""' IAMtfkY~/ ~ < "' "'-· / .... " 0 -i> z ... E w 1- / E X c 0 ..... - .~:.--- ,_j' '-... E X c 0 SfAl [ (7' C Al,.I F()fi'HtA THE PACIFIC SOUTHWEST WATER PLAN Upper Colorado River Commission Staff November 8, 1963 I. INTRODUCTION The following statement is based upon an examination of the report on the Pacific Southwest Water Plan that was released by the Secretary of the Interior on August 26, 1963. Comments, opinions or suggestions have been prepared for the purpose of raising questions and aiding in evaluating the proposed Pacific Southwest Water Plan from the standpoint of the Upper Colorado River Basin. The four Upper Division States, Colorado, New Mexico, Utah and Wyoming, should be interested in the Pacific Southwest Water Plan (PSWP) because anything that.affects the development of the water resources in one of the Compact-created Basins of the Colorado River could have effects of some nature on the other Basin. Although we are primarily interested in the development of the water and land resources of the Upper Basin and its future destiny we must carefully analyze any resources development plans of the Lower Basin in order to ascertain their possible effects on the future of our Upper Basin. In making our analyses we should strive to be objective and fair, and constructive and cooperative, in spite of the questionable tactics that have been used against us in the past by certain Lower Basin entities in their attempts to forestall the authorization of the Colorado River Storage Project and participating projects. We must, however, never lose sight of our objective of protecting the interests of the Upper Basin. The information in Section II, Digest of PSWP Report was derived either from the De partment of the Interior Task Force report dated August 1963, or related back-up data and information. - 1 - N E " V A D !.OS ANG~l.~S . ~-AQUEDU CT C A L F 0 R N I A I' c MAJOR .WATER FACILITIES ~",_ EXISTING ~ - UNDER CONSTRUCTION -.. - PROPOSED UNITED STATES · DEPARTMENT OF THE INTERIOR BUREAU OF RECLAMATION PA'CIFIC SOUTHWEST WATER PLAN LOCATION MAP JVNE 1963 P;Jo~OENtX. ARIZOM I J / f l A. NEW MEX. A R (!) N A I CENTRAl I HE GATE ROCK ARIZON.A PROJECT DIV~ ~!j. ~<.AQUEDUCT SYST~M .. PALO VERDE ''-.:,-,\ l DIV. DAM ~ PHOENIX ...,..._.......... HOOK DAM 0 lordsburg •••••• II. DIGEST OF REPORT A. NEED FOR THE PACIFIC SOUTHWEST WATER PLAN (PSWP) l. Southern California and the Lower Colorado River Basin depend either partially or entirely upon the Colorado River and its tributaries for water supplies. The Task Force report treats these adjoining areas having common water supply problems and needs as a single region called 11 The Pacific Southwest. 11 2. " . .. the Pacific Southwest is defined as the Colorado River drainage basin, downstream from Lee Ferry to the Mexican border, plus the southern portion of California, bounded on the north by the Santa Barbara County line and the Tehachapi Mountains 1 and on the west by the Sierra Nevada Mountains northward to 1 and including, Mono County. 11 3. The Pacific Southwest is the most critically water-short region in the Nation. Its future growth is dependent on the provision of an adequate water supply. In area, it embraces about 190,000 square miles. 4. The acute water problem has been accentuated by the fact that the rate of population grow'.:h for the area has been phenomenal. The 1930 population of the Pacific Southwest, most of which was in Southern California, was about 3 1/2 million people. By 1960 the total population had increased to about 11 million. By 2020 the area is expected to have about 260% more people than in 1960. This pop­ ulation projection assumes the availability of water. 5. Uses of water have been changing. For instance, in the Phoenix, Arizona area 50, 000 acres of irrigated land have been shifted from crop production to housing and.industrial sites during the 1950's. In 195 0 Southern California had 5 70, 000 acres of urban­ ized land. By 19 60 there were 1, 080, 000 acres urbanized, and during the same period 60, 000 acres of irrigated land went out of crop pro­ duction. B. THE WATER PROBLEM 1. The Pacific Southwest is an arid region where, historically speaking, the wa ter supply has always been a problem. - 2- ( 2. Prior to 1951 the conflicting claims of the States of the Lower Colorado River Basin impeded Congressional consideration of legislation to authorize construction of projects to divert Colorado River water. Since 1951 the progress of water development in the Lower Basin has been more or less at a standstill as the result of the intent of Congress as expressed in a resolution that Bills relating to the proposed Central Arizona Project "be postponed until such time as use of the water in the Lower Colorado River Basin is either adjudicated or binding, or mutual agreement as to the use of the water is reached by the States of the Lower Colorado River Basin. 11 3. On June 3, 1963 the U. S. Supreme Court announced its opinion in the case of Arizona v. California . The Report claims that this opinion appears to clear the way for the development of a com­ prehensive plan to meet the present and future needs of the Pacific Southwest region. 11 The final decree of the Supreme Court will re­ move that uncertainty which has prevented Congressional consider­ ation of Lower Basin development since 195 1. 11 4. There is not sufficient water in the Lower Colorado River to provide for the needs of the area. 5. Except for the various Indian reservations where water supplies have been reserved for the expansion of irrigated acreage, it is not contemplated under the Pacific Southwest Water Plan that there will be any increases in irrigated acreage except where a local undeveloped water supply is available. Supplemental water will be made available to maintain the present agricultural economy only. 6. The present economy of the Pacific Southwest area is being maintained by the 11 mining" of ground water supplies. This process cannot continue indefinitely without certain local and over­ all detrimental effects. C. PRESENT WATER SUPPLY AT LEE FERRY As far as the mainstream of the Lower Colorado River is concerned the undepleted, or virgin, flow at Lee Ferry since 1896 has averaged about 14. 9 maf annually. Historically during the same period about 13. 4 rnaf annually have passed this point. The annual historic and virgin flows at Lee Ferry since 1896 are graphically portrayed on the following Figure 1. - 3- COLORADO RIVER FLOW AT LEE FERRY, ARIZONA 28- t4- , 'PROGRESSIVE ,,~ AVERAGE / tO - YEAR / VIRGIN FLOW 20- \ AVERAGE Of : \ : VIRGIN FLOW \ -,_1 ._~.. I B- I-" - " 1\' P\.OTtEO MEND Of YfJIR \; "::.::f 16- ..... ~ ~ ~· ~REAMFLOW 14:.-~t-tr--~rltltMf=J~~~~t:iHtlln-~tlit:-iHtfJhr-Jr~~~-t--1JJ-1t~jt~~~~~~~~-;JR----tr- IN MILLION I! II ~ 1'-- .._ •;:: ;:.': ::~ ,[II a , ·' ~..., !f lr ~- :J ~ t~~ ,:! ~ . 1 . if !I ,, 2- fill ii -" "Tl WATER YEAR G) c ::u m D. FUTURE WATER DEMANDS AND SUPPLIES OF PACIFIC SOUTHWEST 1. Water demands projected to the year 2000 are shown on the following Table 1 . .2 . From Tables No. 1 and No . 2 it is evident that the total annual uses of water in the area, including the 1. 5 maf per year which must be guaranteed for delivery to Mexico, is estimated a t about 17. 75 maf. The present total water supply available to the Pacific Southwest on a sustained yield basis is estimated to be about 16. 41 maf per year. The difference between these two figures, 1. 34 maf per year, represents the apparent overdraft of the ground water basins under long-term, water-supply conditions. 3. The possibilities for filling future demands from present sources of water are enumerated as follows: (a) Redistribution of available water. (b) Conservation of available water by such practices as river channelization, phreatophyte eradication, lining canals and ditches, improving irrigation practices, stopping trespassers from diverting water along the Colorado River between Davis Dam and the International Boundary, evaporation reduction, etc. (c) Reclamation and reuse of available water. (d) Water quality improvement. (e) Improvement of watershed yield. 4. New sources of supply. (a) Desalting the sea and brackish water. (b) Importation of water from water surplus areas. 5. Future demand-supply relationships are shown by the following Tables No. 2 and No. 3 . - s - Sheet 1 of 2 Table 1 Pacific Southwest Water Plan Projected Water Uses Unit: 1, 000 a. f. Develoement Year Item Present 1975 1990 2000 Depletions--Compact Point to Lake Mead Tributary depletions 11 260 350 370 390 Future reservoir evaporation 1:/ 100 100 100 Lake Mead gross evaporation 840 900 850 800 Southern Nevada uses from Lake Mead Y 20 90 140 160 Southern California uses Y Colorado River areas 470 470 470 470 Desert areas 3,590 3,830 3,930 3,980 Coastal areas 2,270 3,290 4,230 4,930 Conveyance losses Y 930 990 1,040 1,080 Arizona uses Y Colorado River areas 800 800 800 800 Bill Williams River Basin 25 30 30 30 Central Arizona Project area 4,490 4,880 5,370 5,780 Other Gila River Basin areas 270 280 320 360 Conveyance losses .§./ 800 840 890 940 Mainstream Indian uses below Hoover Dam 1/ Arizona 175 250 350 380 California 25 80 80 80 Nevada 10 10 10 Fish and wildlife use s 15 160 300 300 Net mainstream losses-- Hoover Dam to Mexico 8/ 1,270 1,270 1,270 1,270 lv'iexican Treaty obligation 1, 500 1,500 1, 500 1, 500 TOTAL 17,750 20,120 22, 050 23,360 - 6- Sheet 2 of 2 1/ Includes Little Colorado River and other tributary areas in the States of Arizona , Nevada, New Mexico, and Utah.