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Oi)164 ~ IMPACTS TO CAP WATER SUPPLY The CAP water supply study showed CAP to pump an average 1,566,000 acre-feet annually for 80 traces over the period 1986 through 2050. Average CAP pumping for each year from 1986 through 2050 is illustrated in figure B-3. Figure B-3 shows a consistently declining average CAP pumping from 1992 through about 2040. After 2040, the average pumping appears to stabilize through 2050. CAP does not experience a declared shortage until 2016 when one is declared among 80 traces. From 2016 through 2050, CAP experiences increasing occurrences of shortage (see figure B~4)~, CAP declared shortages occurred most frequently '(17 times) in 2048. Occurrences of declared surpluses and of CAP pumping,above ,its"normal schedule behave,simdlarly and are, illustrated in figures,B-5 and B-6. "These frequencies generally decline from 1992 through 2025. After 2025., the frequencies remain at about 16' and 21, respectively for declared surplus and pumping above the normal schedule. One'might note that the current study's CAP pumping,average of 1,566,000 acre-feet is somewhat higher (7.7 percent) than the 1,454,000 acre-feet average CAP pumping that was determined from the 1985 CAP water supply study. The 1985 study was performed for the period 1985 through 2050. The CAP pumping schedule varied somewhat between these two studies and these differences are listed in the following table: CAP Pumping Schedule (1,000 acre-feet) 1985 1986 1987 1988 1985 Study Current Study 51 NA 486 543 923 1043 1495 1432 If the 1985 study's average were recomputed to allow for the,early schedule differences, it would have averaged roughly 1,477,000 acre-feet. This is "23,000 acre-feet above the 1985 study average. Additional factors which may have influenced the CAP pumping are the differences in Upper Basin depletion schedules between these studies. Portions of the Upper Basin depletion schedule are listed in the table below. UPPER BASIN DEPLETION (not including evaporation) (1,000 acre-feet) 1990 2000 2010 2020 2030 2040 1985 Study 4096 4621 4864 5035 5114 5269 Current Study 4039 4630 4826 4965 5057 5236 Difference 57 -9 38 70 57 33 No quantitative ~mpact to the CAP average water supply ~ay be deternined from the table above. However, the general trend of lower Upper Basin depletions would result in a highe~ average water supply for CAP.