Special Irrigation Issue
Page 6
THt wtrmtn
GAZETTE-TIMES
Crop Irrigation Nation's Prime Water Consumer
By M. N. LANGLEY
The earth's total water sup
plyespecially its fresh wa
ter supply needs to be put
in perspective. Estimates have
been made that there are ap
proximately 326 million cubic
miles of water on this earth.
This is reassuring until you
consider that about 317 mil
lion cubic miles of that total
supply is salt water in the
oceans, and an additional 1
million is salty ground wa
ter. This leaves 8 million cu
bic miles of fresh water, or
less than 2',a per cent of the
total world supply. But here
again, 7 million cubic miles
is tied up in the polar ice
caps, and the remaining 1
million cubic miles of fresh
water is largely confined to
our underground aquifers.
Hence, only about one
hundreth of one per cent of
the earth's water supply
33,400 cubic miles makes
Winter Upkeep
Adds to Life
Of Water Gear
Without good maintenance
you cannot expect your equip
ment to last or operate sat
isfactorily. The following are
some suggestions:
Store aluminum pipe off
the ground and away from
birds and animals to protect
it from chemical and phys
ical damage. Inspect coupler
gaskets and store them in
water. Replace those with
hard or cracked edges. Clean
gasket seats. Repair bends
and leaks.
Inspect sprinkler heads.
Repair or replace those with
bent parts, weak springs, or
those that do not rotate prop
erly. A sprinkler should ro
tate one to two turns per
minute. Many times replace
ment of the washer and
smoothing the washer seat
will correct rotation problems.
Inspect nozzles for enlarge
ment. The size of the nozzle
is stamped on it. Use the
shank end of a drill bit to
check the wear by inserting
it into the nozzle.
Check horizontal centrifu
gal pumps. Remove suction
cover and check wear at the
impeller eye and wearing
ring. Replace and repair if
the clearance is greater than
recommended by the manu
facturer. If leakage through
the packing gland has been
excessive, remove the gland
and packing. Cheek wear on
the shaft sleeve. If worn or
grooved, it should be replac
ed. In reassembling, always
use new packing.
Turbine pumps. Have thrust
bearing checked once a year.
This should be done by a ser
vice man. Following a long
shutdown, start oil drippintj
in oil-lubricated deep-well
turbines a week before start
ing. Electric motors. Check re
sistance of insulation (meg
ohm check) in large motors
annually. A change in resist
ance readings from year to
year will provide a guide to
baking and revarnishing
schedules. Store small motors
in a dry place. Check con
tacts on starting switch and
main switch for burning.
When starting in the spring,
be sure rotation is right. In
iiotw lit hiiTh winter humid
ity, 480-volt motors should be j
ih.iiniii.ihK- Hried heforp beine '
hooked up. This can be done
by heating or by an electri
cal short circuit. The latter
should be done only by a
qualified service man.
As printed in "Sprinkler
Irrigation in the Pacific
Northwest A Trouble Shoot
er's Guide".
up the fresh water stored in
lakes (30,000 cubic miles),
the atmosphere (3,100 cubic
miles), and the world's rivers
300 cubic miles). The wise
use of water and water con
servation in connection with
irrigation involves utilization
ot a total supply of fresh sur
face water and ground water
comprising only one- or two
hundreth of 1 per cent of the
earth's water supply at any
moment. And when this sup
ply is limited only to the wa
ter in the atmosphere and in
the earth's rivers at any mo
ment, then only about one
thousandth of one per cent of
the earth's water supply is
involved.
To paraphrase an old say
ing, its "water, water every
where, but mighty little fresh
water within the economic
reach of the farmer!"
The earth's total water sup
ply remains almost constant,
going through the hydrologic
cycle of evaporation from the
' land surfaces, and transpira
tion from vegetation; conden
sation in the atmosphere, and
nrorinitatinn hack to the Wa
ter and land surfaces. Water
falling on the land surfaces
may become soil moisture
and support plant growth, it
may enter ground water aqui
fiers, or it may run off into
streams. Of course, water in
the latter two stages finds
its way often after use and
reuse, back to the ocean
again.
Use of Water for Irrigation
The dynamic nature of the
hydrologic cycle is illustrated
by the fact that while the
earth's entire atmosphere
holds only about 3,100 cubic
miles nf water at anv mo
ment, the average annual
niofinitntinn in the conti
nental United States alone is
annroximatelv 1.430 cubic
miles in volume.
In 1909 irrigation will rep
resent more than 80 per cent
of the total consumptive use
nf the water withdrawn from
streams and the underground
in the United States. Irriga-,
tion consumptive use toiaieu
57.1 million acre-feet in 1900,
about 84 per cent of the to
tal use for all purposes. By
1905, irrigation consumptive
use had increased to 72.5 mil
lion acre-feet, about 83 tier
cent of a total use of 87.1
million acre-feel.
Irrigation Trends
The Bureau of the Census
lakes a census of irrigation
once each 10 years and col
lects some limited data on
irrigated acreages each five
years in connection with its
census of agriculture. The
last such census was in 190U,
tm.ilW, r, intnrim r-nnvlte in '
mill cm 41IVV....1 -..
1904. Reclamation conducts a
rather complete annual cen
sus of the irrigated acreage
and crop production on fed
eral reclamation projects, but
this represents less than 20
per cent of the total irriga
tion in the United States.
In any event, judging from
the best data we have been
able to assemble, irrigation n
general and sprinkler irriga
tion in particular, has been
expanding significantly. Dur
ing the 10-year period, 1958
through 1967, the total irrigat
ed acreage in the United
States increased from about
30 million acres to more than
45 million acres, an increase
of aporoximately 26 per cent.
Of these acreages, about 3.2
million acres were irrigated
by sprinkler in 1958 and T.6
million in 1907, an increase
of over 4 million acres of
130 per cent during the 10
ye"r period.
This increase of more than
4' million acres in sprinkler
irrigation over the past 10
years is shared by a!l reg
ions of the nation hut it
has been especially marked
in the West. Nearly a third i
1,335,000 acres occurred in ;
the Pacific region. Here the
sprinkler irrigated acreage in
creased from about 925,000
acres in 1958 to 2,260,000 in
1967.
The growth of sprinkler ir
rigation on the Columbia Bas
in Project in Washington has
been much more dramatic
than the national average.
The total irrigated acreage on
the Columbia Basin Project
increased from 238,300 acres
in 1958 to 452,800 acres in
1967. Of these acreages, about
54,800 were irrigated by
sprinkler in 1958 and 179,700
acres in 1967, an increase of
about 125,000 acres or near
ly 230 per cent during the
10-year period compared to
the national increase of 130
per cent.
The project's distribution
system was initially laid out
for gravity irrigation and
most of the farms were init
ially irrigated by gravity
flow, so this gain in sprink
ler irrigation represents a
major transition.
The Trend Towards Sprinklers
Several economic and phys
ical factors have caused these
trends toward sprinkler irriga
tion. Foremost is the oppor
tunity to substitute electrical
energy and capital invest
ment (that can be amortized)
for labor that is becoming
more costly and less readily
available.
For example, the capital
cost of a self-propelled
sprinkler irrigation system is
approximately the same as
the cost of leveling land and
developing a farm irrigation
system for gravity irrigation.
The cost of maintaining the
two systems is also about the
same. Therefore, a major eco
nomic consideration by the
water user is the relation
ship between cost of power to
provide sprinkler pressure for
a unit of water and the cost
of irrigation labor to apply
an I'tiual unit of water by
eravitv irrigation. As labor
costs have risen and electrl
nnl nnwpr rates have declln-
nri it has t-xvnme more and
mnrn fnnuihlo fnr the farmer
to substitute electrical power
for farm labor and convert to
sprinkler irrigation.
With sprinkler Irrigation
the farmer can irrigate:
(1) Shallow lands, without
disturbing the topsoil by land
leveling;
(2) Steep lands without
problems of excessive runoff
and soil erosion; ana
(3) Sandy lands, without
excessive deep percolation
and related fertilizer leach
ing.
a a result of these advant
ages, lands which would have
been considered nonirrigable
for gravity irrigation are fre
nuentlv susceptible for
sprinkler irrigation. This con
vertibility permits a consoli
dation of individual farming
operations and ot project ais
Iribution systems to most ef
fectively serve a given acre
age.
We are studying compara
tive costs between open can
al fnr eravitv irrigation dis
tribution svstems and for
Knrinkler irrigation for an ar-
pa of aDDroximately 20,000
mwc in thp fiarrison Diver
sion Unit in North Dakota.
Preliminary indications are
that a closed pipe system de
cWmuri fnr cnrinklpr irriga
tion can be constructed with
in the cost range of an
nnen ranal pravitv system as
originally planned ior mat ar
oa Thic io nnssihle nartlv be
cause a dominantly closed
ninfl svslprm for sDrinkler ir-
ricrjitinn means that a much
more comDact area of land
can be served for a like irri
gable acreage.
RRIGATIQN
SYSTEMS
"If you can plow it
Farmore can irrigate it!"
a Field Engineering Service
Complete Well Testing
Automatic Irrigation Systems
Irrigation Parts & Supplies
Installation Service
Estimates and Financing Available
RAINBIRD EQUIPMENT RED JACKET
IRRIGATION SYSTEMS
LAVNE & BOWLER
RAINCAT PIERCE
IRRIGATION
"COVERING ALL OF EASTERN OREGON"
FAMHORE
Pump and Irrigation
Athena Ore. Ph. 566-3533
We Sell
More Than
This
i - ' t. : 3
mi
This Much
More:
CORNELL
IRRIGATION
PUMPS
RAINBIRD
SPRINKLERS
STEELUME
COUPLINGS
RISERS
WESTERN
HYDRAULIC
SPRINKLER
MOWERS
Pettyjohn's
FARM AND BUILDERS
SUPPLY
Heppner
Ph. 676-9157