The Winslow mail., 1911-02-04
SHOWS OF A SEASON
Value as Source of Supply for IT.
rigation Is Limited.
Agricultural Operations Are Most Sue
cessfuI at Attitudes Below 5000
Feet, With Possibly Some
Exceptions.

streams CndC duOrQ Il0 prlnclpdl
sources of supply for irrigation rise
along the Continental divide and the
parallel ranges to the west, or among
their spurs. The snowfall Of value
as a source of supply for irrigation
during the summer may safely be linn
tied to areas in excess Of 1000 feet
in altitude. The area of territory
above 1000 feet embraced in the
states and territories of Colorado,
Idaho, Nevada, Utah, Arizona, New
Mexico is 112,426 square miles, writes
F. H. Brandenburg in the Field and
Farm. California, partly arid, has
6,246 square miles. In the study of
snowfall in relation to irrigation, it
would seem that the ascertainment
Of the seasonal snowfall should prove
of greater value than data as to the
snowfall for the calendar year.
In Colorado the average for the area
between 5000 and 1000 feet is fifty
four inches; between 1000 and 5000
feet, fifty-eight inches; for the next
thousand, the amount is 121 inches,
while for the next 1000 feet there is
an increase, but not so marked,
amounting to 145 inches. In Wyoming
between 5000 and 1000 feet the aver
age is forty inches; between 1000 and
5000 feet, f1fty-seven inches, and prac-
tically double that value, or 10
inches, between 5000 and 5000 feet.
Beginning with the area between 5000
and 1000 feet and taking succeeding
elevations of 1000 feet, the values for
New Mexico are nineteen inches, for
ty, fifty and seventy-six inches re-
spectively, the last being for the area
between 5000 and 10000 feet. In
Nevada, for the area between 5000
and 1000 feet, the records of a large
number of stations give an average of
seventy-two inches; for higher alti-
tudes the data are insufficient, but
the snowfall is doubtless greater.
The same is true of the higher alti-
tudes in Utah, although the records
of many stations in that state are
available for 5000 and 1000 feet and
1000 to 5000 feet, the values being
u1ty-61 luCuOO CLQ 1OA 1AChCO
respectively. For Idaho, Montana and
Arizona, data are available only for
5000 to 1000 feet. In Idaho the
average is 103 inches, in Montana AZ
inches, and in Arizona 46 inches. For
the entire area above 5000 feet in
Colorado the average for the driest
season is ga inches, while for the wet
test the average is $50 inches. In
Wyoming it is 55 inches for the driest
as against an average Of 80 inches
for the wettest In New Mexico the
extremes are 26 inches and So inches;
Nevada, 33 inches and 101 inches;
Utah, 16 and "a inches; and for 5000
to 1000 feet the extremes are: In
Montana, 20 and 72 inches; Idaho, 60
and 100 inches; Arizona, 20 and Sc
inches.
In view of the variations in the
amounts of snowfall Of different sea-
sons, as just shown, it is manifest
that irrigation interests are much
concerned as to the minimum and
maximum amounts that may be ex-
pected during a season. The great
est seasonal amounts of snowfall
within the arid states, shown by the
records, are as follows: Montana, at
Butte, altitude 5,728 feet, "a inches;
New Mexico, at Chama, altitude 1852
feet, 148 inches; Utah, at Park City,
altitude 6,846 feet, 1875 inches; Ari-
zona, at Flagstaff, altitude 6,907 feet,
208 inches; Wyoming, at Battle, alti-
tude 9,916 feet, 246 inches; Idaho, at
Atlanta altitude 1000 feet, 31S inches;
Colorado, at Ruby, altitude 10000 feet,
644 inches; and Nevada, at Fordyce
Dam, altitude $500 feet, 1,067 inches,
the minimum record at this place in
ten seasons being 1913 inches.
During December and January the
snowfall is light along the eastern
slope of the Continental divide and
1t is not uncommon for almost all the
snow that falls earlier in the season
to melt or evaporate under the inf1u-
ence Of the warm chinook winds
which prevail during these months.
April, May and June are exceeding
ly dry in southern New Mexico and
throughout Arizona, while July is a
dry month in northern Utah; in Ne
vada. the dry period extends all
through July, August and September.
On the western slope of the Cont
mental divide, February, March and
April bring heavy SHOWS, while in the
Pacific states heavy SHOWS on the
mountain ranges are generally per
sistent from December to March. Ag
ricultural operations are most sue
cessful at attitudes below 5000 feet,
with the possible exception of locali-
ties where low altitude offsets to
some extent the influence Of altitude.
Such operations are, therefore, car
ried on in regions more or less re-
motely removed from the larger and
more reliable sources of supply.