The Parker post., 1916-10-14

i In an appendix accompanying this
report will be found records in detail
of the official pumping tests and other
data collected. The data is summar-
lied and interpreted as follows
Q.) From the table of drive point
tests the depth from ground surface
| to the ground water plane Is shown
to he generally not less than eight
feet nor more than twenty feet.
The tests of quality of water for
purposes of irrigation are In nine
separate localities. (The test holes
H, andJ, being in small group
around we'll Mol, are taken as one
locality.) Of these nine localities,
two-thirds show fit for irrigation and
one-third not fit, unless used in COM
bination with water of better quality.
Where bad water was found it could
usually be shown that good water oc-
Cured at other points within reason
able distances.
The evidence is that the lift for
pumping when compared with other
localities where pumping for irriga-
ton is carried ON, is quite low and
is very favorable for economy in
pumping.
The location of wells should be
selected after testing to avoid bodies
of poor water. This can be done by
taking inexpensive samples with
drive point and pump.
A1kali in the soil and in the ground
water occurs In some parts, but not
to a serious extent. The conditions
in this respect average about the
same as are found in the Yuma, Palo
Verde and lSaltRiver Valleys.
CO. The list of Logs of wells
shows the fine silts occurring near
the surface of the ground; then the
sands of coarseness increasing with
the depth and finally gravels and cob
4 blestones in the vicinity of one hun
dred feet underground. A few white
clay strata occur. Below the level
OF ground water the materials were
found clean and unmixed with fine
silt or sediments.
A natural separation or grading of
the materials by the rivers action
appears to have taken place. The
coarser and heavier parts occur at
| the lower depths because the more
finely divided matter has been car
ried in suspension by eddies and cur-
rents until after the agitation has be-
come too weak to lift or move the
larger sizes This natural process
has resulted in a good condition of
porosity for the given size of grain
in the strata where ground water per
colates
The level of ground water appears
to be close to the average river level.
This groundwater appears to underlie
the entire area of bottom land. In
my opinion it is continuous with the
water flowing in the river channel
through the interstices between the
grains OF the sands and gravels. This
is the main source of the underflOW
| waters. The running, waters of the
main channel keep the bottom con-
stantly secured and open to percOla-
| tion in the sands and gravles and
during the annual flood season the
materials under and near the river
bottom are powerfully shifted and re-
disposed, thus greatly increasing the
absorption of water into the, undis-
turbed beds beneath the lands on
either side. Wherever there is a
current sufficient to move materials
we find red silts, so characteristic of
the Colorado, is kept constantly in
suspension. 1t is reasonable to con-
clude that at some time in the past
any given placeinthe flood plane has
been occupied by the river channel
and that In the play of forces which
constantly bend and crowd the great
stream, now one way and then am
other, first the boulders grinding
deep below have been left at rest,
then the gravels above them, then
the sadns, and finally the fine silts
which deposit near the top in com
paratively quiet water
The materials passed through by
these well holes below the top soil
beds are mostly silicious sands and