Imperial Valley press., 1938-02-15
DISTRICT
REPORT
CONTINUED

In the WestmOrland area, there
is large block where the water
is within 6 feet of the surface, and
most of this area has water within
10 feet. In the central portion. of
the valley, between the railroad and
the Alamo channel, there are large
areas where water is within 6 feet
and many others where water is
within 8 feet of the surface. There
is an area between Calipatria and
inland where water is not close to
the surface, but little of this area
has been irrigated for several years.
Even where the test wells do not
indicate dangerous conditions, there
are locally many places where wa
ter is very close to the surface.
Along a number of the roads the
shallow borrow pits have water
standing in them and it is not at
all uncommon to see water in the
burrows in fields which are close
to canals. When it is considered
that the entire valley is covered
by a network of canals, all of
which are contributing to the seep-
age problem, it becomes apparent
that a great many acres have been
rendered productive on this
account
No detailed estimate has, to our
knowledge, been made of the total
area rendered unprOductive by
seepage and high grOundwater, but
from general observation it is ap-
parent that this includes not only
large tracts, but portions of many
otherwise productive farms. In the
aggregate, the productivity of at
least 100000 acres of agricultural
land has been impaired seriously.
The presence of high water table
does not constitute the only danger
to the agricultural prosperity of
the valley. The irrigation waters
contain about one ton of salts per
acre foot, and removal of these
salts must be effective if agricul-
ture is to be permanent.
SALT BALANCE
During the three-year period
from February 1890 to February
1888, the United States department
OF agriculture, in cooperation with
Imperial Irrigation district, made
certain Investigations to determine
the amount of salts brought into
the Imperial Valley by the irriga-
ton supply and removed from it
by drainage and waste water. A
large number of samples of the
irrigation water were analyzed, gen.
orally at weekly intervals, and SIM
liar analyses were made of the dis
charge of Alamo river and of New
river near the Salton sea. The
results of this work were reported
to the district by C. S. Scofield
on March IA, 1888, in part as fol-
lows:
1T would appear that under
present conditions the character of
the salts contained in the irrigated
land of the district is undergoing
gradual change While the guam
tity of chloride is diminishing, that
Of the other constituents is in
creaSing."
Dulh IllLo JllltC-yCdi ptllOu -
068,000 acre feet of water were
brought into the Imperial Valley
from the Colorado river; this ir-
rigation supply carried with it
about 100000 tons of dissolved
solids. During the same period of
time, drainage water and waste
water which found its way to the
Salton sea aggregated 2,725,000 acre
feet and contained substantially S.
100000 tons of salts. The consump-
ton of water was therefore 1,448,0O0
acre feet per year and there were
left behind within the Imperial
Irrigation district over $4,000 tons
per year of salts of one type or
another, equivalent to roughly
tons per irrigated acre per year.
CHARACTER
OF SALTS
Such an accumulation of salts in
the irrigated portions of Imperial
Valley is indicative of serious con-
dtions. Consideration must be given
to the character of the salts dis
placed from the soil and subsoil of
the valley and to the nature of
the salts which were left behind
when water was applied to the
land for irrigation.
(To be Continued
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