State of Florida
Department of Agriculture
NATHAN MAYO, Commissioner
Tm1 T1IIHUN11 PESS-rAuPA- 4Di ,:
r ---------- ~-
Hulletin No. 51
History of LIBRARIES ag
State and: L. 5
-Need for D
Factors Af T
Run off Col
Soil and It
Kind of Sc A,
MIethods o! 17
The "Mole' 18
Flat Land .. 19
Economics 0 -
Developmen .. ..... ... 21
"Flukkus" Type of u ..................................... ................ 21
The Chamber Wheel up.........................................................
Centrifugal Pum ...................................................... 22
High-Head Centrifugal lump............................................ 2
Selection of Centrifugal IPumps ..............................................
Centrifugal Pumps for Low-Lift Duty............................. 24
Horizontal Centrifugal Pumips................. ........... ...... 25
Horizontal and V tical Screw Pumps........................ ... 25
Portable Screw Punmp Units............................. ............. 26
Suction and Discharge Pips..................................................... 27
Sources of Power for Pumping Units.................................... -.
) acknowledgments ........................................... ............ ..... 28
Drainage and Water Control
By RALPH STOUTAMIRE
D RAI.NA(G: and water control are- two of the most inipor-
tant factors involved in growing agricultural and horti-
cultural crops in several great areas of Florida. Fertility
of the soil is the most valuable of all natural resources in this
state. Unlike many minerals. gases and oils. the soil is prac-
tically inexhaustible. if proper methods of management are
employed. However, fertility of the soil alone is not sufficient
to produce crops. A satisfactory balance must be established
between the amount of water and air in the soil.
In other words. water control is of primary, importance
in the future development of Florida's agricultural'and horti-
cultural crops. In many cases this means that gravitational
water must be removed from the top 3 or 4 feet of soil so as to
permit air to enter the pore spaces in the soil and provide room
for satisfactory root and plant development. There are ap-
proximately 18,00.000 acres of land in Florida classified as
- swamp, overflow or tidal marsh. all of which require drainage
hi some formI for successful agricultural enterprises. However,
when drained the ready supply of moisture. or nearness to the
water-table, makes possible the production of crops profitably.
Such soils enable the Florida farmer to grow fresh winter crops
and ship to northern markets when they can not be grown else-
HISTORY OF LAND DRAINAGE
The history of land drainage in Florida has been marked by
many adversities that are slowly being overcome by the inven-
tion of modern power machinery. Dipper and clam-shell
Sdredges have been responsible in a larger degree than prac-
tically any other inventions, for the successful development of
water control areas.
The real era of land drainage began in this country about
1850 when Congress passed the Swamp and Overflowed Land
Act. Under this act those portions of the public lands which, in
their natural state were too wet to cultivate, were given to the
states in which they lay with the understanding that the sev-
eral states were to drain and sell them. However, most of the
states realized that under the common law only a small amount
of drainage was possible. To assist in the work of drainage,
4 DEPARTMENT OF A(IIICI'LTI'It
statute laws have been passed from time to time whereby .a
majority of landowners might combine for constructing the
ditches and drains needed for mutual drainage and force an
unwilling minority to join in the enterprise and pay its share
of the cost Few legislatures have met in the last 50 years
without the passage of one or more acts or amendments to the
drainage law, to the end that the land owners miglt more easily
reclaim their lands.
*(*. J' :.,,. '. ,' : s:
Fig. Exterior View of HObbore Pumplag Station of South Florida
Conservaacy District nar Bille Clad
Former Governor X. B. Broward is clearly entitled to the
credit for starting Everglades reclamation, and practically all
drainage and water control of muck and peat land in Florida
date back to the program of Everglades drainage launched by
him in 1904, following the transfer of title in 1903. of over
20,000,000 acres of such lands to Florida by the federal govern-
ment. The status of land drainage in Florida in 1920 is indi-
cated below, and these figures need little revision to bring them
Total area, acres...............................................3 111,040
Total acres in farms ........................................ 6046 691
Total acres improved........................................ 2,297271
Acres provided with drainage........................ 147,940
Needing drainage....... ........................................ 687,021
Unreclaimed swamp and overflowed lands in
IDRAINA(GE ANI WATER CONTROL 5
FUTURE DEVELOPMENT OF WATER CONTROL
It is difficult to forecast the development of water control in
this state, but it is estimated that in the Everglades alone
500.000 acres will be reclaimed during the next 10 years. This
prediction is based on the demonstrated fact that with water
control sugar cane and other crops can be grown successfully
in this vast area.
Since the Everglades constitute approximately 12,000,000
acres of the total 17,900,000 acres of unreclaimed land in the
state, a large part of the discussion in this bulletin will deal
with water control in this region. The general principles of
drainage and water control are applicable alike to all those
areas in Florida where drainage and water control of this na-
ture are practiced.
Figl. 2. Gladeview Drainage District Pumps: Left, 48 x 18-inch Menge; right,
54-inch Wood Screw Pump. In the foreground is shown the type of removable
flashboard dam used to facilitate movement of dredging equipment
STATE AND FEDERAL PROJECTS
Most major water control projects, by reason of their magni-
tude and the expense involved, must be undertaken by state
and federal governments, individually or jointly. Wherever
possible the system should not only provide outlets for flood
waters during the rainy season but also should provide locks
and flashboard dams with sufficient storage capacity to allow
the farmer to obtain water for irrigating crops when needed.
The largest project of this kind in the state is located in the
Everglades. It is made possible through the Everglades Drain-
age District as well as numerous smaller sub-drainage districts
6 DEPARTMENT OF A(llICTULTlHREl
throughout the state. (See Figure 1.o The control of. the
water of Lake Okeechobee is an inmmense task. meriting federal
attention and assistance. Recently the United Mtates appropri.
ated $7,000.000 for the purpose of more effectively controlling
this great inland body of water, very largely with a view 'to
preventing any recurrence of the disasters of 192l and l!rt
-. ...*.-",:: '*'* -
Fig. 3. Pumping Station near Clewlston. Note the overhead spray irrigation system
nl the background
Water control is just as necessary for successful fanning in
certain areas of the state as Cash registers, computing scales
and other modern business machines are to the successful mer-
chan t or business organization. Therefore, the individual farmer
will often want to, and be compelled to provide his own local
water control system, even though the state and federal govern-
ment establish and maintain the larger general system.
NEED FOR DRAINAGE AND WATER CONTROL
Many vegetable crops, such as eggplant, beans, tomatoes,
potatoes, etc., suffer for moisture when. the soil water-table is
3 or more feet below the surface. Field observations have
shown repeatedly that the water-table is often lower than 3
feet during winter when the greatest amount of Florida's vege-
tables are being grown. Moreover; crops on such soils, whether
muck or peat in the Everglades or mineral soil elsewhere, show
evidence of injury from lack of water. Many irrigation sys-
tems have been installed, in order to prevent the loss from such
conditions. Figure 3 illustrates a large overhead irrigation
l)RAINA(IE AND WATER CONTR()I, 7
system in the Everglades. Many others are to be found in
different parts of the vegetable-growing areas of the state.
Few records are available as to the deptlh of water-table
necessary to provide sufficient moisture for plant growth in
Inuck, peat and mineral soils in the state. Ho\Niever, there
have heei nlany observations made in conjunction with re-ordls
of the flctuation of the ground water table. lThese observa-
tions indicate that where the water-table was 3.5 feet below the
surface for any length of time the plant suffered from lack of
moisture. They also indicated that where the water-table was
within 1 foot of the surface, the plants suffered from too much
moisture. When the water was about 2 feet below the surface
the plants were in a healthy condition. As a result of these
observations it is believed that the water-table should be main-
tained at a depth of approximately 2 feet.
Fig. 4. Grove irrigation by bringing the water through underground pipes.
releasing'it through surface hydrants (see insert upper right) and finally dis-
tributing It through open furrows. This outlet is the latest In surface irrigation.
S DEPARTMENT OF AGRICULTURE
Fig. 5. Young avocado grove protected against drought by overhead spray rrigal
tion. This project is located on over-drained, high, pine land which would be
worthless without this protection.
IMPORTANCE OF SOIL AERATION
In tile average well-drained mineral soil the pore spaces
amount to approximately 50 percent by volume of the total
volume, and of this half 25 percent is filled' with capillary
water and the remaining 25 percent is air. The proportion of
water would be much greater than this in organic soils.
The combination of water, oxygen and solid matter in the
soil furnishes the food and energy for the countless soil bac-
teria and fungi which live in the soil. The activity of these
organisms depends on the proper balance. of these soil con-
stituents. In a large measure these organisms prepare and
make available plant food directly or indirectly. If the soil is
wet there is little oxygen and, as a result, the soil bacteria pro-
duce substances undesirable and injurious to higher plants.
Hence a soil must be aerated or ventilated for best results.
Drainage removes excess water, lets air and oxygen into the
soil and ventilates it. Rain water in percolating through the
soil produces an aeration process that is beneficial. As the
water passes downward in the earth, fresh air is drawn in to
replace the water. The changes in the pressure of the at-
mosphere from day to day also assist in ventilating the soil.
This aeration process is essential for all productive soils. On
the other hand there can be too muich aeration, and too great
a solution effect on the plant food elements in the soil, which
may result in depleted fertility. This is illustrated by many
of the open sandy soils in the state.
)ImINAXA(IE AM) WATER CONTROL. 9
FACTORS AFFECTING SOIL WATER
Of all the factors which affect soil water. precipitation (rain-
fall) is one of the most important. A knowledge of precipita-
tion, ailtount and distribution, is of primary importance in flood
control and drainage work. The engineer's problem is pri-
imarily the removal of excess water anl the return of needed
water. If he lhas no available records coverilig rIln-olf, he is
P7 li PIER=
FT MlEiS IT PID1cE
Fig. 6. These graphs show the average monthly rainfall at various weather
bureau stations in Florida. The first bar in each group is for January, the last
one for December.
compelled to estimate the run-off from his knowledge of pre-
cipitation, elevation, etc. If the amount of water available or
the amount to be removed is incorrectly estimated, the project
will be a failure. Therefore, precipitation records as well
as elevation are fundamental in establishing water control
DEPARTMENT OF AGRICULTURE
There are about 45 official weather stations at various points
in Florida. The records from these stations furnish a large
fund of valuable and important information to agricultural in-
terests of the state. Through cooperative efforts of the United
States Weather Bureau and the Agricultural Experiment fta-
tion of the University of Florida at Galnesville a summary ot
the records of these stations has been compiled and publibsed
in Bulletin 200 of the Florida Experiment Station, the authors
being A. J. Mitchell, meteorologist of the United States
Weather Bureau, and M3. R. Ensign, truck horticulturist of the
Florida Experiment Station. This bulletin provides a valuable
guide in determining the run-off coefficient necessary on the
various drainage projects in all parts of the state. The Experi-
ment Station at Oainesville will send free copies. of this bulle-
tin to those who request it. Figure 6 shows the monthly pre-
cipitation of several points in the state.
In the case of land drainage the excessive precipitation
which occurs during comparatively short intervals of time take
on great importance. The best criterion for judging future
precipitation is the occurrence of past precipitation. If reli-
able records were available for a period of several hundred
years, it would be possible to make satisfactory predictions as
to the maximum and minimum amounts of rainfall which might
occur in the future and the frequency of occurrence of a storm
of given intensity. Unfortunately, such records are not avail-
able and it is necessary to introduce a factor of safety in the
assumptions based upon available records. Until quite recent-
ly little attention has been given to the duration, intensity, and
distribution of precipitation at different points within storm
After the famous Dayton (Ohio) flood of 1913, a conservancy
district was formed in order to set up control works that would
forever remove the possibility of recurrence of such a disaster.
Arthur E. Morgan was placed at the head of the engineering
staff of the Miami (Ohio) Conservancy District. Under his
direction a survey was made of the records of 3,054 weather
bureau stations located east of the 103 meridian. Precipitation
prior to 1870 was hot considered in the final study. From these
studies of storms, data have been taken which are applicable
to Florida. Below are listed the excessive rainfalls experi-
enced during periods from two hours to six days since records
have been available in Florida.
The maximum rainfall records for that part of Florida in-
I)RAINAGE. AND WATER CONTROL, 11
eluded between the 25th and 27th parallel north iand the T!th
and 81st meridian west for the last 40 years are:
Period In Inches
2 hours ......................................... ..... ........................ .11
I d ay .................................. ....................................... *15.10
2 days .................................................................... .... 15.40
3 ...................................................................... 1 .10
4 .............................................. ............. ... .. 21.20
S ................................................................... 22.00
S ... ........................................ ..... ....... .......... 22.3 0
Corrected to 1920.
Studies by tie 3liami Conservancy District show that llhe
probable maximum amount of precipitation to be expected in
Florida during periods from one to six days will recur only
once at yearly intervals as shown below:
Once In Once In Once in Onee in
Period 16 years 25 years 50 years 100 years
1 day 9.7 inches 9.9 inches 11.5 Inches 15.1 Inches
2 days 10.8 12.3 14.0 16.7
S 12.5 1.8 15.4 17.2 "
4 1. 14.5 1.1 18.0
5 "4 14. 1.6 17.5 19.1
6 1.0 1 6.1 18.8 20.0
RUN-OFF CONSIDERATIONS FOR ISOLATED PROJECTS
Because of the newness of tile country ain a lack of full
tunlderstanding of all of the unknowns there is a wide diversity
of opinion regarding the proper run-off co efficient to apply on
different siAed areas. However, observations have been made
during the last five years that would indicate the general trend
of requirements on peat lands. The small, isolated tract of land
is under a distinct disadvantage since peat and Imuck dykes are
rather unstable barriers to the flow of water. The element of
seepage is much exaggerated by the fact that the perimeter of
tihe piece of land is extremely high in proportion to the land
that it incloses. For example, the perimeter of a 20-acre tract
is 3.960 feet while the perimeter of a 640-acre tract is only
21,120 feet or a ratio of 5.34 to 1. The ratio of the areas is
640 to 20 or 32 to 1. From this comparison it is apparent that
the length of dyke inclosing a tract of land has a very definite
influence on the seepage to be expected.
12 DEPARTMENT OF AGRICULTURE .
When this 20-acre tract of land is included in a drainage
trict having a systematically designed water control planthi..
element of seepage in of but small moment. Observations' i
at Hialeah during the overflow of October, 1929, and ar o E
of the records of one of the large drainage districts 1i u~
Everglades during 1930 indicate that the seepage factor' -it.
negligible when a substantial dyke is built. The failulizo
drainage district pumping units to maintain control has.
nearly all cases, been traceable to weaknesses developed inl'S
dyke system. This is the most vulnerable part of any reelin
tion plan in the Everglades. Safe dykes can be iuilt and n :
tainted at a comparatively small additional expense and ie'
benefits derived therefrom are many times this small added.
cost. .. -?
SI I I -
1oo aoo o00 400 SoD O don see soon
Isolated Area Drained Acres
Fig. Pnremry estimates of pumplag capcty in terms of equivalent rum-- S
In 24 hours on mall isolated areas within the Everglades.
Preliminary observations of pumping requirements for iso
lated areas varying in size from 10 to 1,000 acres are shown
graphically in Figue 10. The run'of co-efficient shown on this
chart is plotted from data gathered -over a period of only five
years and consequently lacks positive authority and should be
considered as an estimate only. Projects that have been ex-
posed to maximum rainfall conditions seem to fall within rather
close limits and this graphic presentation may be taken as a
IDRAINXAMI AN]D WATER CONTROL 131
SOIL FACTORS INVOLVED IN IRRIGATION AND
The primary Ipui'lose of drainage and water control is to
carry off excess water in the soil which is injurious to plant
growth. This may be accomplished by the use of some form
of under-drain or open ditches. The chief factors in deciding
which method to use are the structure or physical composition
of the soil and topography. Hence, it is necessary for the engi-
neer to understand the subject of soil physics before lie can
intelligently design a drainage system. While soil physics is
a very wide field, it is evident that only the most important
phases can be discussed and these only briefly, leaving the more
extensive data on the subject to the standard treatises on soil
physics, which should be in every drainage engineer's library.
SOIL AND ITS FORMATION
Since mineral soils are derived from a variety of rocks which
have been disinteatgrated by physical agencies, decomposed by
chemical agencies and mixed with more or less organic matter,
they would be expected to vary in physical as well as chemical
A large majority of mineral soils have been derived from
materials which have been transported by wind. water and
other agencies. Hence they are often stratified and contain
impermeable layers. Swamp and marsh soils have been derived
from vegetable materials grown in place. But they often have
impervious underground strata. A large part of the flatwoods
of Florida is underlain with either a "hard-pan"' or clay
stratum. Both of these subsoil structures are semi-permeable
to water which affects the water control system in a number of
ways. Another soil property affecting drainage is that of soil
texture. Open, porous, sandy soils do not lend themselves to
deep open ditches.
The peat soils of the Everglades have been formed by inter-
mittent decaying of grasses and water vegetation over a very
long period of years; hence it is distinctly fibrous and spongy
in nature. They always have a high water holding capacity.
But the structure of the soil stratum is rather continuous and
of such a character that water does not easily move through
it horizontally. When this structure is broken down, however,
horizontal movement of water will result. It is on these types
of soils that the "mole" system of drainage is most beneficial.
14 1)DEPARTMlEN.T OF A(GRICULTI.'RE
SUBSIDENCE OF ORGANIC SOILS
Superficial drainage such as was the case of the early experl- "
,iients on tie peat and muck lands of the Everglades has re,
suited in a distinct shrinkage, caused by the drying onut. and
oxidation of the soil during dry periods with a resultant _I .of I.
volume. If the water can be controlled properly, the shlritnkge
will be reduced to a minimum and the soil, at the same tmne,
made more productive: Since the Everglades is a low, flat
expanse of land having no appreciable natural water coiue,
a different problem arises in controlling the water than in many,;:
parts of the United States. The question is not only one of'
drainage but also of definite water control....
CLASSIFICATION OF SOILS
Mineral soils are composed of varying mixtures of clay,-silt-
sand, gravel and organic matter and are classified according to
the amounts of these substances which they contain. The defi-
nitions of the more important soil classes are as follows:
1. Sands contain more than 75 percent of sand.
2. Loams contain from 30 to W0 percent of sand and less than
15 percent of clay.
3. Gravelly loams contain front 25 to 50 percent of gravel,
much sand and little silt.
4. Sandy loams contain 'from 50 to 75 percent of sand and'
less than 15 percent of clay.
5. Silt loams contain 50 percent or more of silt, less than 15
percent of clay and some sand.
6. Clay loams contain front 15 to 25 percent of clay, much
silt and some sand.
7. Clays contain 25 percent or more or clay and much silt.
8. Mucks contain front 15 to 35 percent of organic matter.
9. Peaty loams contain from 15 to 35 percent of organic
matter, a large amount of sand and a little clay or silt.
10. Peat contains 35 percent or more of organic matter and
sometimes some sand, clay and silt.
The greater the content of clay present in the soil, the slower
the movement of soil water. A knowledge of the texture of the
soil will be of material assistance in laying drainage and irri-
I)lAINA(E. AIND 1VATEl CONTROL, 15
$omei soils are naturally poorly I drained. tlue not only to the
amount of precipitation, but to the nature of the underground
staratigrlaphy as well Iti elevation.
The accompanying table (see page 16) gives an outline of
some of the properties of important agricultural soils of Flor-
ida, including those naturally drained. Here poor drainage
means a water-table of less than 1.5 feet from the surface for
a portion of the year. Some form of drainage is necessary for
the poorly drained soils in tile table.
Kt -' ~ .
1 ~ ~ r A CLI ~
Fig. 8. Small screw type water control pump developed at Port Mayaca Farms,
KINDS OF SOIL MOISTURE
Air-dried soils contain a small amount of moisture, depending
on the texture of soil, humidity and other factors. This moisture
is similar to that in air-dried hay. This is known as hygro-
scopic water and has no value to plants. Jf air-dried soil is
allowed to Iecome saturated with water and then allowed to
drain, tile water absorbed or held is known as capillary water.
This is the water used by plants.
Soil water, above the point of maximum capillary capacity
and up to the point of saturation, is called gravitational water
SUMMARIZED CHARACTERISTICS OF FLORIDA SOILS.
I COLOR I
DMAOnage I 9trito I Tompo by
18,19 1 MI IbtOll
M. Po or IO? y IToltlod PItle ld uiu Po~l h,.
l I G.h lom di rddhy -lt bl U lb ei SWlSm l ,
IIL I aod I reltreut
Mde I d ULiktmy Wolf wloit y Ild solid BeN
Fie llowhlp I Flito I Daayto I Yelot dnt i ldevldto CIImONu ToatM.
Spoor I btek motid I Plastic rolt aendnd dtmnd
GI aI I I l R inle l itor
011100 ,lle Good G ray to lid Ried ti cholit I i t 1111 ioill UmIlo i,,k,
*I| I tm_______
In Pow Imy IopI d I .p td u iton l
I White oran I bNla1 C1o1 U whi
lion oor Gray rdt'"a iNdqoa let ad wtrla
_____^__ ,__y1'"" I~l'-eaif
hlok ?I Poor aIu I liu Phitle ll opi ilntl Tr
Norfolk Goi Gry Yt ow i k 1 l( | i 1101 Ilelln ,
SNIl cIy raoin
OnatNel God lm ih"la trod w Frelt I bll1 1" dy C 1 oCm id
Ihil. 10 o alink
ilm Ba"h GOwd I Brwnilh "Broawraty "P"lt I %I Cla I hat,
I I I mad I trek
P ind IPor .. ...tomer' o Il e lab l 1Nail 1 ibbae
?portsoth Poor 111 LU1 hteto WoI loll Iauw r OilUg i ad
I whlla and dI t uh
Pa wr Anto BW Mk Prowlole hoi Ima,
kB t" I it k Pio it- Unlduatla xarina S814in0
|I I- totl I Id i l ittWm
SII Good I Y light Whit I Lo i 1 hd PapinOwlf
| llny I Min, lad I i ^
'*C ropWlidlar Ithoai now h~rwn on thle uiuoll
DRAINAGE AND WATER CONTROL 17
or free water. This is the water which is injurious to plant
growth and it should be removed by drainage. The percentage
of gravitational water also varies with the depth below the
surface, the surface soil under saturated conditions usually
containing a larger amount than the subsoil because of differ-
ence in texture.
The. rate at which gravitational water moves downward
through the soil depends on size of the soil particles, size of
pore spaces, granulation of the soil, organic matter in the soil
and openings in the soil made by cracks, by burrowing of
earthworms. and animals and by decayed roots of plants. In
coarse-grained soils, percolation is much more rapid than in
line grained soils, notwithstanding the fact that the latter soils
are more porous.
Rate of percolation is the important factor in the design of
the drainage system. Since for different soils it is necessary
to study the soil structure in each case, a soil auger should be
part of the engineer's field equipment, and samples of the sub-
surface and subsoil should be taken at representative places
to determine the texture of the soil studied. It is often pos-
sible to compare samples of the soil under consideration with
samples taken from a field which is satisfactorily drained by
a system of known depth and spacing of tile or mole drain.
METHODS OF CONTROLLING GRAVITATIONAL WATER
The common method of water control in low, flat lands is
that of flooding and open ditches, because there is an ever-
present supply of water that can be had at a minimum expense
by installing low-lift pumps and allowing the water to flow
through open ditches to the fields where needed. Another
valuable consideration for this type of water control is the
fact that the ditches provide an excellent means of removing
excess water during times of heavy rainfall. The main disad-
vantage of this system is the tendency of raw peat and muck
soils to retain gravitational water for periods too long for satis-
factory plant growth under continued excessive rainfall. The
use of some type of under-drain in conjunction with open
ditches will overcome this tendency. The effectiveness of water
control in all parts of the world has been increased by the intro-
duction of under-drains to such an extent that this practice
has been accepted as the most practical yet.employed.
One of the most important problems front an agricultural
viewpoint in peat and muck soils is the ability to maintain a
uniform condition of soil moisture. This can only be accom-
plished by combining subsoil drainage and such methods of
IS DEAI' RTMINT OF AfRICULTURE
tillage as will check the loss of water from the soil through
evaporation. Ability to maintain the proper balance between.
capillary water and air in the soil hastens soil building pro-
ceses that break down the vertical fibrous structure of peat' ,'
THE "MOLE" TYPE OF UNDER-DRAIN
Realizing the importance of very accurate control of ground '
water in muck and peat soils of the Everglades, Florida agri-
cultural engineers delved back through the experiences of the
past and decided to experiment with the "mole" method of
sub-irrigation that had been used to some.extent many years
ago on the Disston Sugar Plantation in the Kissimmee Valley 3
and in the San Joaquin Delta region in California. The equip-
ment used at that time was rather crude, but by applying mod-
ern caterpillar treads and improving the mole design, a very
satisfactory piece of machinery 'resulted. See figures 9, 10
Fig. 9. Early type of "mole" plow. It has been modernized by the use of a heavy
A powerful tractor is utilized to pull the "mole" through
the relatively soft muck and peat at depths varying from 18
to 42 inches below the surface. This opens a drain 5 inches in
diameter through which gravitational waters flow, as is usually
accomplished by the use of tile drains. Experiments were made,
using various spacings to determine drainage, irrigation and
aeration influences when these mole drains were either used
for drainage or sub-irrigation instead of clay or concrete tiles.
After three years of observing their operation they have been
ID)RAINAGI AND) WATER CON'I'1OL 19
pronounced satisfactory to such an extent that the largest
sltgarcane plantation in Florida has adopted this method for
use on aipproxiiimately 20,000 acres of muck and peat soils. The
cost per acre of the "mitole" operation is very low, and could
be repeated at intervals of front three to five years, when
f '. ... 7" : : r . .- ;." .
Fig. 10.A "mole" drain discharging into a lateral ditch. The 1-foot length concrete
tile inserted in end of drain retards cutting of the bank. This drain has been in
operation four years. The screen, lifted off to the right, protects the drain from
The usual spacing of the moles is 50 feet. Lateral ditches
which connect with the main supply and collection canals are
cut at intervals of one-fourth mile, Thus large-volume, low-
head pumps are able to maintain the very accurate control of
the water table necessary to profitably grow sugarcane as well
as many other crops under which this system of sub-drainage
and irrigation is maintained.
FLAT LAND DRAINAGE
Drainage of flat lands is dependent on creating a condition
that will force movement of water from the soil. In other words,
this means that differences of water surface elevations must be
established in order to make water flow from point to point.
20 I)IDE'PARTMIET OF A.iRICLULTIRRE
This can be accomplished by following systematic hydraulic ,
laws in designing a system of channels with proper dimensions .;.
to collect water from specific areas of land in an orderly and *"
systematic manner, and carry it to its ultimate outlet in pro-
gressive and systematic steps in order to create a consistent ": .
and regular flow.
On the higher lands where greater differences in elevationm'
exist. movement of water can be satisfactorily accomplished by
Imeans of gravity. But under conditions existing in low, flat .,-
lands it is necessary to provide large-capacity, low-lift pump-
ing units in order to create a uniform flow in collection ditches
Fig. 11. Sgarcuans Bad uader which the "mo te" syt of dralne i used. n'Ie
Canal Point plant of the Sothera Suga Cempany I an in the background.
Examples of this type of drainage (as well as irrigation
which is so closely associated with it) are numerous. Open
surface ditches play a most important function in the potato
fields of the Hastings area. Around Sanford and Bradenton,
in particular, surface and subsoil drainage and irrigation are
effectively accomplished by means of tile drains. In many of
these areas artesian water is available and is distributed by
means of surface ditches or tile drains which have been so laid
that in wet seasons they serve to remove excess water from the
land. Thus such drainage systems serve a double purpose.
ECONOMICS OF LAND DRAINAGE
Reclamation of land is primarily a business enterprise and
if the increased income from the land as a result of the im-
provements is less than capital invested, the system is a failure,
regardless of how efficiently the drainage system functions.
A conservative estimate of the increased gross revenue which
the land will produce as a result of water control should be
made preferably in comparison with increased gross revenue
D)RAINAG(i AND WATER CONTROL 21
obtained oni nearllv land of similar soil characteristics. Net
income is found by dedutiing from gross incoimie ile cost of
raising a crop.
Net iincoie per acre represents mlloetary ibenelit to the land-
owner. (leneirally benefits derived from a water control sys-
tenll greatly exceed the cost of iamp)rovemlents. It imist lhe re-
imenllmbered. however, thalt an open ditch system will not provide
complete drainllage and that tlie cost (f ditches nimust not he so
ichllli that wlheni cost of miole or tile drains is added total cost
will exceed thie heIelit derived.
DEVELOPMENT OF PUMPING MACHINERY
Owinl to the almlnost universal necessity of pullmips for water
control purposes in lloridla. a wide variety of water-moving
eqtuipilmelit lhas Ieein1 deve-lolped. This development lias. been so
rapid that a treatment of ille evolutlion of water control pumilps
discloses minaiy nlniqcle installations. They vary widely both as
to capacity, ell'iciency anld excellence of design.
Fig. 12. 'Flukku" installation at entrance of a culvert through a dam. It has a
boat propeller driven by a Ford automobile engine which is located in a tin shack.
"Flukkus" Type of Pump: Anmong the first pumps to be u sed
in Florida for artificial drainage were those commonly known
as the "flukkus." See Figure 12. The flukkus pumpl consists
of a boat propeller, a drive shaft anld some source of motive
power, usually a Imulch-used and discarded Ford, Buick or other
automobile engine of doubtful operating characteristics under
such load conditions. The boat propeller was placed in the end
22 DEPARTMENT OF AG(lKII'LTI'lE .M:
of a culvert or a wooden box and the drive shaft connected to 't
the engine through a universal joint.
SThese pumps, while usually of very low efficiency, have
pointed the way to the average farmer, showing him that by -
the movement of water onto or off of his land at the proper
time his crops amay be successfully produced under more ad-'ll
vantageous conditions. The trend: naturally is toward the liore
scientifically developed pumps of higher efficiency. The flnk-
kus, however, has had a very definite place in the evolution of
the low-lift, large-capacity water control pumps in Florida
.. ..... .........
Fig. IS. Small Meao pump installation used for drainage of a IO0-cre citrus grove
owned by C. A. Wala. Orange Vlla, Davie.
The Chamber Wheel Pump, certain types of which have been
used for drainage, is practically a meter, the discharge b ing
in proportion',to the speed. Because of the pulsations set iip
due to the alternate accelerating and retardation of the water
that is pumped, there are well-defined limits of speed that
may be established without injury to the pump. While the
centrifugal pullp may be forced to an extent that is limited
only by the power of the motor or engine driving it, the linmita-
tions of capacity for the chamber wheel type are found in the
Centrifugal Pumps in various forms have been used for drain-
age work where large volumes of water must be elevated only
a few feet. There are many reasons for. the popularity of the
centrifugal pump, among which might be mentioned initial
cost, reliability of operation. simplicity of construction and its
DIRAINAGE, ANN) WATER CONTI'ROL4
ability. when forced, to develop a capacity much greater than
its rated capacity. It is efficient if properly designed for the
conditions under which it is operated.
A clwep but fairly efficient form of centrifugal pumpli tha
was inucth usedx a few yearl ago is the vertical-shlart. wood-bo.
plnip. Many are still in use but of late they have given way
to 11more substantial pumps nmiade entirely of metal. Tlhese older
pumnlps usually were driven by a quarter-turn belt or rope drive
that does lot prove entirely satisfactory under field conllitions.
The mIore niodern plants are usually driven by electric motors
or engines directly connected to the puimp shaft, eliminating
tie losses naturally occurring from belt or rope drive.
Fil. 14. Riser type overhead pray irrilatioa on ive-acre ppper field at
White Belt Dairy near Miami.
Hligh-Head Centrifugal Pumps: (centrifugal pumps are well
aduptedl for use when irrigation and frost control are tlhe only
requisites. They iay eI used oi the high pressure systemm
necessary for the t r types of overhead spray systellms now
eiig installed in all parts of ilorida. Many of tile different
makes of double-su tion centrifugal pumps at tain efficiencies
as igh as 75 and ll percent. See Figure 14.
Selection of Centrifugal Pumps: It is inltortant when select-
ing a pump that all of the possible known factors in the prol-
letim it known fully before the ipumll is ordered to apply to tlhe
1. A careful determination should lie made of the friction
losses occurring in the pipe line from the paump to the most
remote nozzle to Ib served. A satisfactory friction head table
will be furnislled by any responsible pump manufacturer. A
safe figure to assume in any pipe grid is a loss not greater than
5 feet Iwr 100 feet of pile used. It is much better to pay out
a few dollars anore in the original pipe installation than to
continue to pay throughout a period of years in excessive gat.o
line, fuel oil or electric power bills. Tile motor necessary to
drive tile pump for a system often may be reduced many horse.
24 DEPARTMENT OF AGRICULTURE
power by substituting a size or two larger pipe than was
2. Be sure that the suction lift is not greater than the pump
is designed to meet. Several cases have come up in the past
where it was necessary to lower the pump into a pit because
the water level had been drawn down below the limit of tlhe
pump's ability to lift water out of the well.
3. It is well to remember that you usually get what you pay
for when buying any kind of pumping equipment. The cheaper
the pump the less efficient it is likely to be.
CENTRIFUGAL PUMPS FOR LOW-LIFT DUTY
In many cases the low-lift centrifugal pump fits into the sur-
face or sub-irrigated project iu excellent fashion. The type
of pump to use is usually determined by the source of water
Fig. 15. Two 30-horsepower electric motors used to drive Worthington Axiflo screw
pumps at Butler Farms, Inc., west of Deerfield. Each pump delivers 8,100 gallons
of water per minute against an -8-foot head.
Where the water supply is taken from a canal or lake where
much dirt and foreign matter will be encountered it is often
better to sacrifice a few points in efficiency to a more open
design of impeller, such- as the single-suction, open-impeller
type made by nearly all manufacturers of centrifugal pumps.
Naturally the more efficient pumps are designed within nar-
rower limits and clearances are less, with the result that more
difficulty will be encountered in cases where gritty, dirt-laden
water is to be handled. However, tie average installation is
made where the water supply is relatively free from such
debris, and the double-suction, close-impeller centrifugal pnmp
I)AINAI.A(;l AND WATER CONTROL 25
fits the condition of service equally well and tie Ihorsepower
to drive the pump will be materially reduced.
Wllenlever the irrigation
system is to be perntanelntly r
installed at one point froilm iH
year to year. it will be found ii.t ,1 t" 1
tht aa directly collnnllcted
pmpi which receives its
power ftroil an electric i0lo- ... I'
to or solle type of internal :i
combustion engine, will proveO i i
im ost satisfactory. Experi-
ences of the past indicate i.t
that the average individual I
who does install pjlllinillI L
Cquip)lnent with the idle: illn
mind of using his tractor to
drive the pulllp will find lh;t hat.
lie needs the tractor just as B
much for the cultivation of '
his crops as he does for Iump- :
ing. as a final result he
usallS v l)Urliases an electric Fig. 16. Motor reduction gear and
lll c automatic control panel for a 42-inch
motor or a gasoline engine to American Well Works centrifugal pump
located on the west unit of the Pahokee
drive the pump and further Drainage District near Pahokee.
sacrifices the advantages ob-
tainable through the application of the directly connected unit.
Horizontal Centrifugal Punmps: Centrifugal drainage pumps
with horizontal shafts usually have suction and discharge pipes
which, with the pump, form a syphon with the pumin at the top
at a convenient height for exalnination and for repair. Varia-
tions in the level of suction and discharge sides do not affect
the pump and the lift is always equal to the actual difference
of level, while the head the puimp must develop consists of the
static lift plus the various friction .losses in the pumpl andl
Horizontal and Vertical Screw Pumps: Screw ipmnp have
been developed ranging from 1 to 12 feet in diameter, tile
largest having capacities up to 700 cubic feet per second. The
lift ranges up to 10 alnd 15 feet. A e)rbination centrifugal-
screw pumlp lias been developed that i/especially suited to be
driven by elec-tric motors or internal ,Icnobustion engines. Elec-
tric motors or full Diesel engines are usually applied to in-
stallations of the larger types. The blades of this type of
Ipump are s.: designed that the load is practically constant
froni a iilulinilul to a mnaxilmuml lift when running at a constant
speed. When electrically driven. a vertical electric motor is
-; )I'DE\ARTMENT OF AGRICULTURE
iiuially employed, being directly connected to the vertical shaft
of the pump, thereby eliminating the difficulty of belting or
gearing these pumps with horizontal power units.
Fig. 17. Two of .three 54-inch wood screw pumps installed at the Bare Beach
Spumping station of South Florida Conservancy District.
Portable Screw Pump Unite:. Several pump builders- in Flor-
ida have developed screw type pumps that may be shifted from
point to point in the fields by the simple expedient of backing
a trailer up to the bank of the canal, picking up the pmnping
unit and hauling it to a new location where by a reverse opera-
tion it is set in place, lined and levelled and made ready for
operation as soon as the tractor can be shifted into place. It is
believed that the future will bring irrigation to a more stable
condition and the average farmer will know where he will need
pumping equipment and provide a small pumping plant of a
SUCTION AND DISCHARGE PIPES
In water control installations where the lift is usually be-
tween 4 and 10 feet. the loss at the entrance of suction pipes
and the kinetic energy thrown away at the end of the discharge
pipe together make up a large percentage of the energy used.
These losses increase with the square of the velocity of the
water at entrance and discharge and the velocity in turn de-
pends upon the diameter and area of the pipe at the two ends.
The larger the area at these ends, the less is the velocity and
energy loss and vice versa. For this reason the practice. for-
lIRDAINXAE ANI) W'AT'ER COTROL) 2T
inerly collmmon, of designing the suction and discll;arge pipe to
he thle samte dia;liter throughout is now being very generally
abandoned, although descriptions of such plants in which tihe
funldatental laws of Ihydratulics are disregarded occasionally
lindl their wi;y into thie technical pIres.
Fig. 18. A 30-inch Wood screw pump used for primary lift on an irrigation system
at Port Maysca.
Until recently tile entrance loss li;s usually beei estimated
at 0.!:3 of the velocity lead at the entrance. Bulletin 91( of the
Engineering Experiment Station, Ianiversity of Illinois. con-
tains evidence that this loss of efficiency is too high and sug-
gests a value of 0.62. The discharge loss is equal to the head
at tile end of the discharge pipe. If tile pipes are round and
tlhe diameter lie doubled at the suction and discharge ends, the
areas will be multiplied by 4: and with pumping at a constant
rate, there will be entrance and discharge velocities, one-fourth
as great as with pipes of uniform sixe. Discharge losses vary
as the square of the velocity so they will be reduced to one-
sixteenth of tile loss in a1 pipe of uniform size.
Tile importance of this matter of pipe expans"io is illustrated
in Figure 19. It is assumed that the pump lan1 s are designed
for aI discharge pipe 2 feet in diameter and the mean velocity
is 10 feet per second. The length of straight pipe is taken as
SOURCES OF POWER FOR PUMPING UNITS
The source of power to lie used in thle pumping station is a
question which sh41oul lie considered when the project is first
28_ I)ElTPAlTM31NT OF AGIltI'I.TIUt'
tontempclated.' Much care should be exercised in the sele:.ioli
of the motive equipment necessary for the operation of the
pumping station. In some cases it Imay be found advisable to
use some form of internal combustion engine. However, Iwhere
electric transmission lines are available it is often possible to
take advantage of much simplified, design in the reclamation
plan. since with electric service it is possible to extend lines to
poi nts where the best advantage muay be taken of natural grades
to secure a more positive control of tihe water-table within the
n d e r t i e electrically -1T
driven pump plan of reclama- -
tion it is not necessary to ex- I j
pend large sums of money in I
digging drainage canals to j
bring water from tihe whole .
district to a single pumping C s
station. It is frequently ad- ~
vantageons to consult with L
your local electric service
company to ascertain /
whether satisfactory ar-
rangemments can be made for -
the electrification of the e
project you have under con-
sidcration. Some of the pub-
lic utility companies in the *
state have trained engineers -*
who may render valuable as- t
distance to you in tile solu-
tion of your water control
problem. And alwa ys re- 2- -s"e -.r s. e.o
member that your count ty Dianet -r of Opennrg
agricultural agent is in a po-
sition togive you worthwhile d texpad suction an discharge
In securing material for this bulletin the author has fre-
quently consulted not only the publications mentioned but per-
sons in the state who are in positions to know what is correct
and best and ]modern in the field of drainage and water con-
trol. Among those who have been consulted are Forrest D.
Banning, agricultural engineer for the Florida Power and
Light Co.; Dr. O. C. Bryan, agronomist and soil expert, and
Frazier Rogers, agricultural engineer, both of the Florida Col-
lege of Agriculture. Mr. Banning and T)r. Bryan read and
erilicised the manuscript.