BOARD01417

• Board Meeting Date: 5/24/1999
• Description: WSP Section - Colorado River Basin Issues - Upper Colorado River Commissioner's Report - Historic and Continuing Interest of the Upper Basin in Preserving Secure Interstate Allocations
• Board Meetings - Doc Type: Memo

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allocated under the 1931 Seven Party Agreement for use by irrigation districts in the Imperial, Coachella,
and Palo Verde Valleys. The next 550,000 af is allocated for use by Metropolitan.49 Metropolitan then
has the next priorities for the use of water in California over 4.4 maf, which total 0.662 maf. Because of
California's ability to use the unused apportionments of Arizona and Nevada, Metropolitan had been able
to divert to nearly the full capacity of its aqueduct. ,0

5. California had experienced a five year period of severe drought", and the years 1988-1990
were the driest three year period of record in the Upper Colorado River Basin.

6. The population of the service area of Metropolitan was about I 5 million people, and was
projected to increase to 18.2 million people by the year 2010, translating to an increased water demand
of about I mafby the year 2010." Metropolitan projected shortfalls in water supply in the year 2010 of
between 0.74 and 1.71 maf.53 As a result, there was an urgent need to "firm up" the yield of
Metropolitan's Colorado River water supply so as to divert the full capacity of the Colorado River
Aqueduct.

7. In the context of the development of the 1991 and 1992 Annual Operating Plans for Colorado
River Reservoirs, California requested the other Colorado River Basin States agree to a declaration of
"surplus" conditions by the Secretary of the Interior, which would allow Metropolitan to be guaranteed
the ability to divert water to the full capacity of its Colorado River Aqueduct. As noted above,
increasing water use in Arizona and Nevada threatened to drive total consumptive use in the Lower
Basin over 7.5 maf, which could have resulted in cutbacks to Metropolitan's Colorado River water supply
at a critical time.

8. In contrast, the states of the Upper Division - Colorado, New Mexico, Utah and Wyoming"
had yet to reach development of their entitlemet1ts to consumptive use of the Colorado River System,
and were not expected to reach full development for many years."

"The Seven Party Water Agreement of August 18, 1931, from Selected Legal References, Vol. I, Upper
Colorado River Commission, Salt Lake City, 1965.

50Since 1984, actual deliveries through the Colorado River Aqueduct have been in excess of 1.2 mafper
year. Source: Upper Colorado River Commission.

"In 1990, before the 1991 "March Miracle" rains which put the drought on temporary hold, statewide
precipitation in California was 28% of normal, reservoir levels were generaIly about 50% of normal (less than the
1977-78 drought), and snow pillow samples were 12-24% of normal. Water users in the Metropolitan Water
District of Southern California were cut back 17% overall, and agricultural water users received 65% cutbacks from
State Water Project deliveries. Source: Metropolitan Water District of Southern California.

52The Regional Urban Water Management Plan for tlte Metropolitan Water District of Southern California,
November, 1990, pages II, 36.

53ld., Table 1II-6.

541922 Colorado River Compac~ Article lI(c).

"Provisional water consumption estimates for the Upper Division States total about 3.7 maf. Upper Colorado
River States' Depletion Schedule, 1994, Upper Colorado River Commission. When combined with the estimated