40 
Y • • r • 
Fig. 4A. Annual percentage devia¬ 
tion of natural (1) and regulated 
(2) Delta outflow from mean natural 
Delta outflow (1921-1978 computed 
with 5-year running means (annual 
mean natural Delta outflow, 1921— 
1978 = 27.7 million acre feet). 
the month of May of natural (1) and 
regulated (2) Delta outlfow from 
mean natural Delta outlfow for May 
(1921-1978), computed with 5-year 
running means (May mean natural 
Delta outflow, 1 921 -1 978 = 4.1 5 
million acre feet). 
*21 25 *31 35 *41 45 *61 55 *61 55 *7175 
Y • a r • 
Fig. 4B. Percentage deviation for 
the month of April of natural (1 ) 
and regulated (2) Delta outflow for 
April (1921-1978), computed with 5- 
year running means (April mean 
natural Delta outflow, 1921 -1 978 = 
4.10 million acre feet). 
Fig. 4D. Percentage deviation for 
the month of June of natural (1) 
and regulated (2) Delta outlfow 
from mean natural Delta outflow for 
June (1 921-1978), computed with 5- 
year running means (June mean 
natural Delta outflow, 1921 -1 978 = 
2.51 million acre feet). 
44 
