The Hawaiian gazette., 1908-10-09
CONCERNING
ARTEs|AN WELLS

Editor Advertiser: Now that the
subject of our artesian wells is being
discussed, it may be worth while to
submit another theory to account for
them. 1t is certainly remarkable that
artesian wells with head OF. over Al
feet above sea level, and flowing from
10000 to 10000 gallons an hour, should
exist near the coast of small island
like Oahu.
As the late Judge MeCulIy truly stat
ed in an article in the Hawaiian An.
nual for 1882,
"The weight of scientific opinion
had been that it Glowing water from
artesian wells) could not be obtained,
as the Islands were supposed to be so
constituted geolog isally that the lava
and coral formation did not furnish
such basin with upper and lower
strata of clay or other impervious ma.
terial, as when pierced would cause the
water therein to rise to the surface,
and that the lay of the land, permit
ting the escape of subterraneous water
into the ocean at a lower depth made
it unreasonable to expect that it would
rise through boring above sea level.'
1t is noteworthy that such wells, in
which the water rises above sea level,
are found only in Oahu, with the ex-
ception perhaps of Kappa on Kauai.
1t is also a significant fact that Oahu
is the only island which has been
elevated as whole in comparatively
recent geological time.
The article quoted above contains the
following explanations: ''It seems evil
dent that the great central stratum of
water-bearing rock must be completely
separated by impervious strata from
the surrounding ocean. Were it not SO,
the water it contains would escape into
the sea instead of standing forty-two
feet above it, as it appears uniformly
to do in this district. From the borings
it appears that the retaining strata are
composed of very compact clay. These
are covered again by other strata of
sand, coral and clay, with everything
beds of lava. 1t seems to be neces.
sary inference that these strata were
gradually and successfully deposited
growing volcanic mountain as then ex-
listing. On all ocean beds, slow depo.
sition of sediment from the land are
constantly accommodating, upon which
near the shore sand is also deposited
and coral grows. On this ancient vol.
canic coast lava has occasionally over
flowed these lower strata, enlarging the
area of the island.''
Z L.
far inland, but which must once have
been the vicinity of the sea beach.
They have rapid slope, in conformity
with the normal contour of the ancient
volcanic nucleus Of the island. The
upper and inner edge of these strata
appears to be alta point which is now
forty-two feet above the sea level, but
which must at the period of original
deposition have been just below the
level of the, sea in which the clay was
deposited. Hence it is to be inferred
that later elevation of the region al
least forty-two feet above sea level
took place at the early period in ques-
ton. -
1t is now generally agreed among
biologists that such an elevation of the
island of Oahu has taken place.
Furthermore the records of the bor-
ings of the successful artesian wells
mention stratum of clay Immediate
ly above the water bearing rock in ev
cry instance.
The appendix to Prof. j. d. Dana IS
work on "Corals and Coral islands,
gives the records of the borings of tif-
teen artesian wells in and around Ho-
nolulu.
The water supplied by these wells is
fresh and pure, although it rises from
depths varying from 300 to 700 feet
below sea level.
During the first few years, the water
from the artesian wells was allowed to
run to waste, without any control, un-
til it's general level fell about eight
feet. As stated in Baldwin g Geog
raphy: "This led to the passage of an
act by the Legislature, making it OBJ
ligatory that all flowing wells be
capped.
Observations taken since on the gov
eminent gauge have shown that the
artesian level rises and falls in accord
ance with variations in the amount of
rainfall.
On the whole, the theory advanced in
the article quoted above seems to the
writer to be the most probable one.
although it may not be necessary to
assume that "the bearing rock
must be completely separated by i'm.
pervious strata from the surrounding
ocean, in view of the slowness with
which water percolates through rock or
gravel, and also of the pressure of the
sea water. VIDA.
-s-<-s--
SAFE ROUTE FOR AUSTRALIA.