The circle banner. [volume] (Circle, Mont.) 1914-1939, 1923-02-23
TREASURE STATE FARM AND LIVESTOCK
IRRIGATION FOR
DRYLAND FARMS

| reservoirs and diking systems. This
would mean much to the state il
the dry Ianders were assured enough
moisture for their vegetables, and
stock feed for the winter. With vege-
tables, garden truck, couple cows
chickens, and meat raised on the
farm each year there need not be any
| starvation rations on the dry farms,
although the large money crop may
be a total failure.
During the winter following 1919,
$34, 100000 was sent out of the state
| for stock feed. This would not have
been necessary even after that record
year of drought if the irrigation pos
sibilities were anywhere near deveI-
oped to capacity.
With few acres of land irrigated
to go with the dry farmers operations
there Is no need of his buying feed
for his stock. He can enlarge on his
livestock operations and be insured
of plenty of feed to carry him
through.
There are already large number
of small reservoirs and diking sys-
TENS on the dry farms of the state
and the owners claim that it is due
to them that they can make a go
of it. These hold back the run off
from the coulees during the spring
freshet season and during storms to
be used for the growing crops. This
is not only of benefit to the dry farm
but 1t also tends to smooth out the
peak of the floods and is beneficial
in this respect also. The number of
these storage reservoirs should be
greatly increased as there are great
numbers of places where they can be
built.
The lack of knowledge on how to
build the dams so they will hold is
probably the reason there are not
more of these private storage sys-
TENS. Some have tried and failed and
by their example have discouraged
others from trying. Earth dams will
nearly always be built by the farmer.
If a very large or expensive dam is
to be built the services of an engin-
eer should be secured. By the OBJ
servance of few simple rules these
farmers earth dams can be made to
hold and the irrigation system made
a success.
/. Location. The reservoir should
be located where the water can be
run out by gravity onto the crops.
2. Site. A site must be selected |
so that the reservoir will hold large |
volume of water for the size of the |
dam. There are many good dam
sites without any large reservoir ca
Dacity above. A coulee with a mar
row draw and wide level flat above
s an ideal condition for a reservoir
Ind dam site.
3. Dam Design. The dam should
De made massive enough to Withstand
he pressure of water. The top width
hould never be less than six feet.
t is a good rule to make it one foot
vide for each foot in height and to
'uild a road on top in which case it
hould be at least twelve feet wide.
The top of the dam should be at least {
hree feet above the crest of the spill {
way. The slope of the upper face 5
hould be three horizontal to one /
critical and the lower face two and :
ne-half horizontal to one vertical :
With an extra wide top the slope may
e cut down a little. The lower face !;
hould be seeded to grass to prevent J
rosion.
4. Spillway. Earthen dams never :
hould be topped by the water. They :
annot withstand the rush of water J
yer them even for a few minutes Z
Tithout being cut and washed away
he size should be large enough to r
AIRY off the greatest flood flow +
Without topping the dam. The neces- :
airy size will depend upon the size, +
hape, and contour of the drainage :
rea above the dam. Allowing a IL
maximum depth of one and one-half f
eet on the spillway, it is recommend
d that the width be twenty feet for
drainage area of one section above
he dam, and fifty feet for five sec ,
ions.
The spillway should be we'll pro- !,
ected from washing out. One of the !,
'est and easiest to construct is a nat :
lral saddle in one of the ridges bord- /,
ring the reservoir. If this is we'll !.
odded it will not be necessary to rip
ap it.
5. Riprapping. The water side of /,
he dam should be protected from the /.
wave action by some sort of riprap- !.
ing. This may be made of rocks
emented together, brush tied in
lunches and anchored or rocks laid
Dose and anchored by wire netting.
6. Dam Construction. The upper
nd lower toes of the dam should be
taxed out and all vegetation and hui
nus removed from the site before
NY fill is made. If the top soil is
oarse trench should be excavated !
o impervious clay and filled with !
light clay to prevent seepage through
nd under the dam. The dam should
e carried up its full width and COM {
acted well while being constructed.
IS usually constructed by the farmers $
he compacting is not thorough and s
he dam will settle, hence the center
hould be built a foot or so higher
han the ends to take care of this :