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Progress Report Series No. 8
Revised June 1948
AGRICULTURAL EXPERIMENT STATION
of The Alabama Polytechnic Institute, Auburn, Ala.
* * * * * M. J. Funchess, Director
CONSTRUCT ION OF FARM PONDS
H. S. SWINGLE, Fish Culturist
Water Supply
Artificial ponds in Alabama are con-
structed by throwing up earthen dams
across natural hollows into which water is
introduced from streams, artesian wells,
springs or the run-off from terraced land.
If the pond is to be constructed by dam-
ming up a stream, it is preferable to
select one with as little flood water as
possible.
Depth of Pond
If a fairly constant water supply is
available, a successful pond 
may be con-
structed with the maximum depth of water
as low as 6 feet, however, a maximum 
depth
of 8 feet is preferable.
If the pond is constructed on a very
small stream or if the water is supplied
by the run-off from terraced lands, a
greater depth for storage of water is
necessary to carry the pond through periods
of drought. In such cases, the maximum
depth of water should 
be at least 10 feet.
Marking off Area for Pond
After the approximate water depth is
determined, the area to be covered by the
pond should be staked off, using a terrac-
ing or surveying level. If the survey
indicates that the pond will have a great
deal of water less than 4 inches in depth,
the proposed water level should be either
raised or lowered to eliminate, as far as
possible, large areas of extremely shallow
water. A large amount of shallow water in
a pond makes the control of weeds and mos-
quitoes very difficult.
State Department of Health Permit Required
A permit from the State Department of
Health is required before the pond is con-
structed. Consult your local Health Offi-
cer for further details.
Clearing Pond Area
All trees and brush in the area to be
flooded and about 15 feet back from the
water line should be cut off as close to
the ground as possible; they should 
then
be either removed from this area or burned.
This will enable the owner to remove fish
by seining when this 
is found desirable,
and aids in the control of weeds and
mosquitoes.
Marking off Area for Dam
All trees and brush should first be
cleared off on the approximate area to be
occupied by the dam. The top of the dam
should be constructed to and maintained at
a height of at least 3 feet above the
water level if the pond occasionally re-
ceives moderate amounts of flood water.
If large amounts of flood water must be
handled, the top of the dam should be 4 or
5 feet above water level.
Using a terracing level or some similar
instrument, the points where the top of
the dam meets the hillside should first be
marked with stakes (Figure 1). Between
these stakes the height of the top of the
dam from the ground should next be de-
termined at several points marked with
stakes. From these stakes the foundation
for the dam should next be laid out as in-
dicated in Figure 2. Stakes should be set
at distances from the center of the dam
twice the height of the dam at that point.
A line connecting the outside stakes (Fig-
ure 2) will then outline the foundation
for the dam. Two sets of stakes at the
ends of the dam and one in the middle are
set to mark the position and width of the
center of the dam. The dam is then con-
structed by bringing the center up to the
II, L a . L a a a a -L P a I L sI - a 1
* 0 * * * *
indicated height and sloping the sides to
the groundalong the outline of the foun-
dation, thus giving the sides a 2-to-1
slope (Figure 3).
Preparation of Foundation for Dam
The area upon which the dam is to be
placed should be cleared of stumps, grass,
and trash. In the center of this site, an
area at least half the area of the founda-
tion of the dam should have the top soil
completely removed down to the original
clay subsoil to prevent seepage under the
dam. Less leakage will result if the first
foot of subsoil is removed, or at least
plowed deeply and repacked; this tends
to break up natural drainage channels and
makes a better bond between subsoil and
dam. The earth removed in preparing the
foundation may be used in the downstream
edge of the dam.
Where the site for the dam is too wet
and boggy to allow teams to clear off the
foundation, this can be done economically
by the use of ditching dynamite. However,
such work should be supervised by someone
familiar with the use of this material.
For information and advice concerning its
use, consult your local County Agent.
Installing Drain Pipe
After the foundation for the dam has
been.properly cleared and dug out, the
center should be filled with good clay as
indicated in the next section. When filled
up level with the stream bed, or with
the lower part of the pond, the drain pipe
should next be installed.
The size of drain pipe needed depends
upon the size of the pond and upon the
volume of water running into the pond. A
4-inch drain will empty an acre pond, with
a maximum depth of 9 feet and an average
depth of 3 to 4 feet, in about 60 hours if
no water is entering the pond during this
period. A 6-inch drain will empty the
same pond in half the above time, while a
12-inch drain will require about 1/9 this
time. In the majority of cases, a 4- to
6-inch drain will be satisfactory for
ponds up to 3 acres in size; while from 6-
to 12-inch drains will be necessary for
larger ponds up to 15 to 20 acres.
The drains may be of cast iron or gal-
vanized iron; the former is much more
permanent. Sewer tile has been found to
be unsatisfactory if used entirely through
the dam, due to cracks developing around
the joints. However, it can be used to
reduce the cost of the drain to some ex-
tent by running the cast iron pipe two-
thirds the total distance 
through the dam
and finishing out the distance to the down-
stream side with well cemented sewer tile.
With the smaller drains, it is cheaper
and just as satisfactory to dispense with
a valve, using a 90 ell and section pipe
running up to the water level inside the
pond. When it is desired to drain the
pond, this section is shoved sidewise, un-
screwing the ell, until the pipe lies flat
on the bottom of the pond For larger
drains, a gate valve is probably the most
satisfactory, although somewhat costly.
It is usually recommended that this valve
be placed inside the pond and that the
valve be operated by connecting a long
pipe to the wheel or stem of thel valve.
In this case, it will be necessary to
build a platform above water from which to
operate the hvalve. Placing the valve 
in
side the pond prevents the drain pipe from
filling with sediment and reduces somewhat
the danger of leaks.
The drain shouiu be laid so that the
lowest part of the pond can be drained.
After it is properly placed, concrete col-
lars should be poured completely around
the pipe at points approximately 15 feet
apart. This should be done both to hold
the pipe securely while the dam is being
built and to prevent seepage through the
dam along the pipe.* The valve should be
opened so that the drain can take care of
the water from the stream while the dam is
being constructed.
Construction of Dam
Soil containing enough clay-to allow
the forming of a hard ball when the moist
soil is squeezed tightly by hand is satis.-
factory for the dam construction. This
soil should be free of leaves, roots and
other trash. Only the most impervious
?
* Clay should then be packed around the pipe,
keeping it sufficiently moist to enable it to
be forced tightly against the underside of the
pipe.
(2)
W Level of top of dam
5 13
D Stream
Figure I. In laying off the dam with a level, first mark points A, 8, C, and D with
stakes. Then determine the height of top of the dam from points C and D.
26'I
2611
1
* Aab f 
If 
f
- p 
0* 
0 0 
0
Figure 2. From stakes 
A, B, C, and D measure 
over 5 feet (or more) 
for the width of the
center of the dam. 
Then drive stakes 
at points from center 
of the dam twice
the height of the dam 
at those points. These 
outer stakes connected 
with dotted
line mark the outline of 
the dam.
13'
Old ground line!1
26526-Mons"
Excavated into subsoil Excavated into
Figure 3. Cross-section through center of the dam, showing 
the 2-to-I slope of the side.
and the approximate area excavated down into the subsoil 
for the foundation.
(3)
clay available shouldbe used in the cen-
ter of the dam.
The moving of the dirt for the dam can
be very successfully done with slip scrapes
and teams, as the soil is most thoroughly
packed by this method. However, tractors
with bull-dozers or rotary scrapes, steam
shovels, and trucks have also been used
successfully where care is taken to pack
the soil as much as possible during con-
struction and where sufficient extra height
is allowed for settling of the dam.
For dams extremely well packed, a min-
imum of 6 inches should be added to every
10 feet in height to take care of settl-
ing; while for loosely packed dams, it may
be necessary to add as much as 2 feet to
each 10 feet in height of the dam.
The top width of the dam should be ap-
proximately 5 feet for dams up to 15 feet
in height. For higher dams, the top width
should be a minimum of 1/3 the height.
The front and back side should have a 2-
to-1 slope as shown in Figure 3. A 3-to-l
slope on the front (or upstream side) is
not necessary except for very large ponds
where the dam must stand considerable wave
action.
The Spillway
The cheapest type of spillway is that
constructed to one side of the dam on the
old hillside. It is extremely important
to build a spillway large enough to take
care of the maximum amount of water which
can be expected. The main cause of fail-
ure of dirt dams is the over-topping of
the dam by flood waters, due to lack of
sufficient capacity in the spillway. Some
idea of the width necessary can be gained
by examining the banks of the stream for
signs of the highest driftwood left by
high water. After estimating the size re-
quired, make it considerably larger. A
wide, shallow spillway is much preferable
to a narrow, deep one, as the former re-
quires less height to the dam and reduces
the number of fish leaving the pond through
the spillway during floods. The water also
leaves the spillway with much less velocity
thus reducing the protection necessary
immediately below the cemented area.
The spillway should be paved with con-
crete for a sufficient distance to carry
the water entirely away from the dam.
Sodd ing and Ri p-rapping Dam
Immediately upon completion of the dam,
it should be planted with Bermuda grass on
the back side, the top and down the front
to the water level. For ponds 1 acre or
so in size which are well protected from
wind by high hills or trees, rip-rapping
the dam at the water line is not neces-
sary, as the Bermuda roots appear to offer
sufficient protection. For larger ponds
or for small ponds exposed to the wind,
additional protection from wave action on
the dam is necessary. Sufficient protec-
tion for most ponds can be secured by
laying rock from one to two feet below to
about one foot above the water line on the
dam.
Filling Pond with Water
Immediately upon completion of the dam
and spilway, the valve may be closed and
the pond filled with water. As soon as
the pond begins to fill, Gambusia minnows
should be added at the rate of 100 or more
per acre of water. These Minnows may be
secured from neighbor's ponds or from your
County Health Officer. They mpst be added
to all new ponds to help control the mos-
quitoes.
Within a week after the pond has been
filled with water, the floating trash
should be removed. This can be done best
on a windy day when all the floatage will
be concentrated on one bank. It then can
easily be removed with forks, rakes or
with short sections of chicken wire fenc-
ing. It is very important that this be
done in order to make mosquito control by
the fish more effective.