The Construction of an Efficient Irrigation Plant 
F. W. Stanley 
Mr. President, Ladies and Gentlemen : 
<,> 
A study of the rainfall records for the 
last 22 years at Orlando, indicate that 
irrigation would be beneficial 17 years 
out of the 22, or ’that your groves should 
have been watered 38 times to get the 
best results. 7 years have been very dry. 
Namely 1892-3, 93-4, 96-7, 97-8, 1906-7, 
’08-9, To-11, or one year in three has 
been dry enough to make the most scep¬ 
tical wish that he had some way of water¬ 
ing his trees. The years 1897-8, and 
1906-7, are still talked of as the years 
when even pine trees died from lack of 
water. The loss from these two years 
alone would pay for an efficient irrigation 
plant. 
We are carrying on a series of expe¬ 
riments in conjunction with portable pump 
and engine and complete soil moisture 
apparatus, at Orlando and hope to be 
able to give you some actual figures on 
benefit of scientific irrigation, within the 
next year or two. 
I will attempt to take up the construc¬ 
tion of the irrigation plant in the order 
in which one would be constructed. We 
will assume first that the water supply 
is at hand, either in form of lake, stream, 
or good well. 
The horizontal centrifugal pump, oper¬ 
ated by either a gasoline or steam engine 
is admirably suited for most of the con¬ 
ditions found in Florida. The centri¬ 
fugal pumps are cheap and very efficient 
for heads up to 150. They are very sim¬ 
ple to care for and wear well. A pump 
with capacity of 1000 gal. per minute 
should be bought for $125.00 which is 
only a small fraction of the cost of the 
complicated triplex plunger pumps that 
seem' to be quite popular. 
The method to determine size of pump 
is very simple, and af the same time the 
least understood. Our experiments in 
studying soil moisture show that your 
grove should be covered with 2 inches of 
water, or to supply enough water to be 
the equivalent of two inches of rainfall. 
Next you should figure on covering your 
grove in about one week. The rest is 
simply a matter of arithmetic. You have 
the quantity and the time. For example 
suppose you have a ten acre grove. You 
will need to cover an acre and one half 
two inches deep in one day if you thor¬ 
oughly irrigate your grove in one week. 
One acre two inches deep is about 54,000 
gallons an acre and one-half would be ap¬ 
proximately 70,000 gallons. This 70,000 
gallons should be pumped in ten hours, 
which is equivalent to about 120 gallons 
per minute. A No. 2 pump would be 
about right for this case. If you own a 
100-acre grove multiply the above by ten, 
128 
