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<br />WATER SUPPLY
<br />
<br />The natural (undepleted and unregulated) flow at Lee Ferry, as determined by the U.S.
<br />Bureau of Reclamation (Reclamation) for Water Years 1973 through 1992 is shown on Table 1.
<br />
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<br />
<br />The natural flow for 1977 at Lee Ferry of 5.0 million acre-feet (mat) was the driest year
<br />on record for the period 1906-1991, and 1983, with a flow of 23.6 maf, was the wettest. The
<br />long-term mean natural flow for the period 1906-1991 is 15 million acre-feet. The period 1983
<br />through 1986 was a period of significantly above-normal runoff. Each of those four years had
<br />a natural flow in excess of 20.0 maf, with a four year average of 22.3 maf. Only once before,
<br />in 1920 and 1921 did 20.0 maf of natural flow occur for two or more consecutive years and only
<br />one other period (1920-1923) had an average natural flow exceeding 20.0 maf (20.4 mat). From
<br />1988 through the 1992 water years flows have been well below normal. Preliminary data
<br />indicates that natural flow at Lee Ferry for water year 1992 is about 68 percent of normal.
<br />
<br />TABLE 1
<br />NATURAL FLOW AT LEE FERRY
<br />
<br />Water Year
<br />
<br />Natural Flow
<br />
<br />1973
<br />1974
<br />1975
<br />1976
<br />1977
<br />1978
<br />1979
<br />1980
<br />1981
<br />1982
<br />1983
<br />1984
<br />1985
<br />1986
<br />1987
<br />1988
<br />1989
<br />1990
<br />1991
<br />1992
<br />
<br />19,435,000
<br />13,307,000
<br />16,150,000
<br />10,723,000
<br />5,023,000
<br />14,660,000
<br />17,337,000
<br />16,935,000
<br />7,413,000
<br />16,108,000
<br />23,647,000
<br />23,511,000
<br />20,163,000
<br />21,883,000
<br />16,924,000
<br />11,581,000
<br />9,107,000
<br />8,662,000
<br />11,399;000
<br />10,200,000 **
<br />
<br />NOTE: 1986-92 are preliminary, subject to revision.
<br />
<br />** Estimated
<br />
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