The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
for the Home
A. M. Pettis
D. S. Harrison
Florida Cooperative Extension Service
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
SELECTING WATER PUMPS FOR THE HOME
In the U. S. today more than 90 percent of the farms
and rural homes have pressure water systems. Some of
these systems receive water from a central supply, but
many have individual water pumps. Florida probably has
the highest percentage of water systems on electrified
farms of any state in the Southeast.
With the population explosion and the trend of urban
families moving to suburban or rural areas, many water
system installations are in new homes. Quite a few units
are being sold to replace worn-out equipment. Unfortunate-
ly, some systems, already installed and working perfectly,
do not fulfill the owner's requirements and have to be
replaced. And in many cases the pump provides enough
water when first installed, but the owner's demands soon
increase beyond the capacity of the pump to supply them.
This type replacement is costly to the owner and could be
avoided by proper design that takes into consideration
The first step in properly selecting a water system is to
consider the water requirements. A pump should deliver
the water needed for a 24-hour period by running not more
than two hours. If the installation is for a farm home the
following data will be helpful:
Livestock water needs* Gal/per/day
Milk Cow 35
Horse, dry cow or beef animal 12
100 chickens (mature) 7-10
100 turkeys (mature) 18
*Taken from USDA Pub. 674, "Planning the Electric.
In addition to livestock needs, each person in the
family will require 50-100 gallons per day. Some present
day usage tables may not indicate this level, but during
the life of a water system, which is 10 to 20 years, it is
anticipated this quantity will be needed.
Increased production means more income and a higher
standard of living for farm people. Plentiful water supplies
for livestock increases production.
For example, in dairy production, a research study
showed cows having continuous access to water drank 18
percent more water, produced 3.5 percent more milk and
10.7 percent more butterfat. Laying flocks with automatic
waterers produced 14 percent more eggs than comparable
flocks that were hand watered. Cattle and hogs having
water constantly available gain weight faster and are
ready for market in a shorter time.
An important consideration in determining water system
requirements is the amount of water needed at a given
time. A family, formerly living in town on a central water
system where several water-using devices may be operated
at once, will be dissatisfied if its individual home water
system does not meet the same standard of performance.
Here are usage rates of fixtures:
RATES OF FLOW
Bathtub 4- 8
Sink 2 3
Lavatory I 3
Water Closet 5
Garden hose (3/4") 5
Lawn sprinkler (small) 3
Fire protection 15
1,000 sq. ft. garden (1 per hour) 11
In the event the bathtub (6), the sink (3), the water
closet (5), and 2 lawn sprinklers (6) were in operation
at once, a total of 20 gpm would be required. It is highly
unlikely that all these uses would occur at once. However,
it is reasonable to assume that three-fourths of these uses.
or a demand of 15 gpm, will he needed. Therefore, a
pump delivering 15 gpm or 900 gph is the minimum size
that should be installed.
The ever-increasing use of water-using appliances, such
as automatic clothes washers, dishwashers. and food waste
disposals, helps account for a continued i increase in
average daily water usage by the rural home. )tlher factors
include the desire for cleanliness which results in more
facilities for baths and more baths than previously. Clothes
are laundered more frequently than a generation ago.
Car-washing is a common practice by rural people today.
A pump delivering 15 gpm or 900 gph at 40-pound
pressure should provide sufficient daily quantities and
adequate demand flow rates for the average rural non-farm
home during the future life of the water system. This
size would include quantities for garden watering and
reasonable fire protection.
Use of a rural home water system to water the garden
will pay dividends in both a better product and more pro-
duction. Under normal conditions, a little extra water at
the right time can increase production by 50 to 100
percent and sometimes more. Under extreme conditions of
dry weather, water that can be applied through the garden
hose from a home pump can mean the difference between
a good crop of delicious vegetables and no crop at all.
An inexpensive perforated hose or one or more sprinklers
may be the only additional facility needed for garden
watering if the pump is large enough.
The next point to consider is the type pump and the
size well. We recommend that a well for a rural home be
at least 4" in diameter. The pump types usually recom-
mended are jets and submersibles. (A submersible requires
at least a 4" well.)
Two kinds of jet pumps are deep-well and shallow-well.
If the distance from the water level to the surface is less
than 22 feet, including drawdown during pumping, a
shallow-well jet may be used. The only shallow-well jet
pumps recommended are those easily adaptable to deep-well
jets. If the water table should drop more than 22 feet
below the surface, the shallow-well jet could be converted
at low cost. whereas replacing the pump would be
expensive. If a jet pump is selected, it must be a deep-well
jet in wells where the distance to the water level is greater
than 22 feet. The practical limit of suction for the jet
is 25 feet.
The submersible pump has many advantages. It gives
more water for the electricity used than any other pump.
The pump and motor are below the water level so it does
not lose prime. Disadvantages are the 4" well requirement
and a higher initial cost than jet pumps of the same horse-
Here is a comparison of water quantities as given by one
(4' level) I h.p. jet 960 gph at 20 pounds;
540 gph at 40 pounds
( 40' eel) I h.p. submersible 1260 gph at 20
pounds; 111 5 gph at 40 pounds
(120' level) I h.p. jet 240I gph at 40 pounds (not
(120' level) I h.p. submersible 905 gph at 40 pounds
The preceding data indicates that jet performance
decreases rapidly with increased pressure and increased
depth. while the submersible drops very little. Also, tlie
submersible gives considerably more water than a jet of
the same horsepower.
Your water system should have a pressure tank of either
42- or 82-gallon capacity. Pressure tanks provide a uniform
pressure and prevent frequent stops and starts of the pump
which wastes electricity and wears out the motor. A
42-gallon tank will enable you to use about 8 gallons of
water between the pump stopping and starting auto-
matically again. An 82-gallon tank will furnish about 16
gallons of water between stops and starts.
There is another type pump -- the self-priming centri-
fugal -- that is occasionally used for the home water
system. This pump has low lift (about 13') and gives good
volume at low pressures. A fine application of this pump is
with a well where the water level is not more than 15'
and from which one or more lawn sprinklers are operated.
If the proper number of sprinklers are used with this
pump, no pressure tank is needed.
Homeowners should be informed about water systems
so they can specify an installation adequate for their needs.
It is penny-wise and dollar-foolish to cut corners on your
water system installation.
Many suburban and rural homes with private water
systems are built for resale by contractors. A contractor
must be sold on the advantages of an adequate water system
to the ultimate owner. He may well use the features of his
water system installation as a selling point for his home.
Prepared by: A. M. Pettis
Extension Agricultural Engineer
D. S. Harrison
Extension Agricultural Engineer
Single copies free to residents of Florida. Bulk rates
available upon request. Please submit (det.iils on
request to Chairman, Editorial Departmentl, Insl.iliile
of Food and Agriculllurial Sciences, niversit y 0of
Florida, Gainesville, Florida 32611.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
Joe N. Busby, Dean
This public document was promulgated at an annual cost of
.' '.43, or 6.2 cents per copy to assist Florida homeowner, n
with private wells.