FREE INSTITUTE OF SCIENCE 
VEGETATION OF SOUTH FLORIDA 151 
years is 53 inches, with a minimum of 40.22 inches in 1902 and a maximum 
of 70.92 inches in 1887. If this amount of rainfall was uniformly distributed 
throughout the year, it would not be a difficult matter to take care of it, but 
it is excessive during the summer and fall, often exceeding 12 inches in a single 
month. It is this period of heavy rain that must be considered in planning 
the drainage of this section. In the months of July and August, 1905, there 
was a total rainfall of 27.95 inches recorded at Kissimmee. During the same 
period, there was but 20 inches at Jupiter, 24 inches at Fort Myers, and 25 at 
Miami. This would seem to indicate that the rain at Kissimmee was increased 
by some local influence that did not exist throughout the peninsula, and that 
probably the rainfall over the entire drainage area did not exceed 26 inches. 
As a fall of 26 inches in any other two consecutive months is the closest ap- 
proach to this amount, it is safe to conclude that 26 inches is an extraordinary 
rainfall, not likely to occur except at rare intervals, and it would hardly be 
wise or prudent to base the carrying capacity of the drains on this amount. 
Since a rainfall of 18 to 22 inches in two consecutive months has occurred three 
times during the last decade, we may reasonably expect the same amount in 
the future. In order to have a fair margin of safety in the storage capacity 
of Lake Okeechobee, canals should be provided having sufficient discharge 
to remove a maximum rainfall of 24 inches from the entire watershed in two 
consecutive months.” 
“From examination of the data available it appears that the amount of 
moisture removed by a mixed growth of vegetation, such as trees, bushes, 
and grass, is at least o.ro inch per day. All the Okeechobee watershed, how- 
ever, is covered with a thick growth of vegetation, there being numerous lakes 
and ponds and extensive areas of almost barren soil, but if this vegetation were 
concentrated on one-half of the area it would cover it quite densely; so, in- 
stead of estimating the water removed by the plant growth at о.то inch for the 
entire watershed, we will restrict it to one-half the area, as more nearly repre- 
senting the conditions in southern Florida. Assuming o.25 inch to be removed 
by free evaporation and 0.05 inch by plant growth, we have 0.30 inch per day, 
or a total of 9 inches per month taken up by these two methods. This is 75 
per cent. of the mean rainfall for July and August, which amount agrees quite 
closely with the results obtained in other places where careful and continued 
experiments have been made. Since the maximum rainfall that is likely to 
occur in July and August is 24 inches, the mean daily precipitation for these 
