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<br /> 1 r:" ,
<br /> .) U'i
<br /> T obi. 3
<br /> DIVERSIONS MINUS MEASURED RETURNS
<br /> FOR MAJOR WATER USERS
<br /> LOWER COlORADO RIVER
<br /> 1967 to 1971
<br /> (Thousands of Acre-Feet)
<br /> Wollter Ycoar
<br /> /967 /968 /969 /970 /97/
<br /> CIlhfornia
<br />Metropolitan Water
<br />Din. ......m............... 1,182 1,105 1,139 1,205 1,204
<br />Palo Verde Irrig. 457
<br />Din. ........................ 365 387 386 384
<br />Imperial Irrig. Dist. 2,860 2,745 2,766 2,751 2,935
<br />Coachella Valley Co.
<br />Water Dist. 453 469 490 448 453
<br />Yuma Project,
<br />Reserv. Di.... ............ 51 56 65 48 51
<br />Total........ 4,911 4,762 4,846 4,836 5,100
<br /> Arizona
<br />Colorado Riv.
<br />Indian Reserv. ...... 200 237 214 224 272
<br />Gila Project ................ 566 559 613 614 666
<br />Yuma Project,
<br />Valley Di.... ............ 171 170 170 Il5 182
<br />Total......... 937 966 997 993 1,120
<br />
<br />Ncovsdll
<br />Pumping from Lake 40
<br />Mead ........................ 27 JI J4 41
<br />Grand T oral ...... 5,875 5,759 5,877 5,870 6,260
<br />
<br />In addition to the major water users listed
<br />in Table 3, miscellaneous users divert from
<br />the Colorado River or pump from wells adja-
<br />cent to the main stream. For the past several
<br />years, gross diversions by these miscellane-
<br />ous users in California, Arizona, and Nevada
<br />are estimated to be more than 150,000 acre-
<br />feet per year.
<br />One of the major operating problems on
<br />the lower Colorado River, which has been
<br />successfully solved, is meeting all water de-
<br />mands with a minimum of waste. The major
<br />diversion for California and Arizona users is
<br />at Imperial Dam, However, the nearest ma-
<br />jor regulating structure to Imperial Dam is
<br />Parker Dam which is located three days flow
<br />time away. The ordered flow at Imperial
<br />Dam is seldom the rate actually required be-
<br />cause of changes in the weather and other
<br />factors occurring during travel time from
<br />Parker Dam. Senator Wash Dam, construct-
<br />ed on a tributary upstream of Imperial Dam,
<br />
<br />provides a limited amount of storage which
<br />is used to balance river flows with demands.
<br />
<br />Deliveries to Mexico
<br />The Bureau of Reclamation controls river
<br />operations so as to minimize deliveries to
<br />Mexico in excess of the 1,500,000 acre-feet per
<br />year guaranteed under the Mexican Water
<br />Treaty. Weekly schedules of deliveries to
<br />Mexico called a "Control Schedule", are
<br />,
<br />made up of estimated return flows from
<br />projects in the YUJ?~ area, re~eases from .Im-
<br />perial Dam for slUlcmg and rIver regulatIOn,
<br />and additional releases required from up-
<br />stream storage, Return flows from projects
<br />below Imperial Dam comprise about one-
<br />third of the total annual delivery to Mexico.
<br />The control schedule amounts and Mexico's
<br />scheduled and excess deliveries are included
<br />in Table 4.
<br />
<br />T obi. 4
<br />DELIVERIES TO MEXICO
<br />COlORADO RIVER SYSTEM
<br />1962 to 1971
<br />(Thousands of Acre-F..t)
<br />
<br />Water
<br />YeST
<br />
<br />Scbedult!d
<br />Deliveries
<br />to Conrrol
<br />M~xico" Schedul~
<br />
<br />Flow (0
<br />M~xico
<br />
<br />Excess
<br />lkliJ'~ri~s
<br />ro
<br />M~xjco
<br />
<br />Excess
<br />Over
<br />Control
<br />Schedul~
<br />
<br />1962 .......... 1,500 1,540 1,763 263 223
<br />1963 .......... 1,500 1,873 2,113 613 240
<br />1964 .......... 1,500 1,549 1,776 276 227
<br />1965 1,474 1,502 1,594 120 92
<br />\966 ..,.,..... \,54\ \,612 1,720 \79 88
<br />1967 .......... 1,459 1,517 1,566 107 49
<br />1968 .......... 1,488 1,541 1,563 75 22
<br />1969 .......... 1,491 I,H5 1,551 59 6
<br />1970 .......... 1,476 1,528 1,566 90 38
<br />1971 .......... 1,501 1,5ll 1,561 60 8
<br />
<br />. The water year total of scheduled deliveries is not necessarily the 1,500,000
<br />acre-foot calendar year obligation undet tbe Mexican Water Treaty.
<br />
<br />Plate 6 shows deliveries to Mexico during
<br />water year 1970-71. Table 4 and Plate 6 show
<br />the close river control obtained in recent
<br />years on deliveries to Mexico. The reduc-
<br />tions in excess deliveries to Mexico are the
<br />result of improved river operations by the
<br />Bureau of Reclamation, additional regulation
<br />provided by Senator Wash Reservoir and
<br />more stringent water scheduling by the wa-
<br />ter users.
<br />Table 5 shows a summary of water deliv-
<br />
<br />17
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