Coeur d'Alene evening press. (Coeur d'Alene, Idaho) 1907-1929, 1909-01-06
STABILITY OF
THE GATUN dam,
om,lsI Report as to This Part Of
Panama Canal.
ruE SINKING WAS EXPECTED.

akafament IS 10 thS nVSN wv "@~~
s..,liro Caused Serious Runners.
e.,,0oss Of the Dam and ExpIana-
,,0r Of Its construetion-No Lalcs
Under It's Site
uvnlsining the settling Of the rock
~. . which started the rumOr that
,ha soundation of the Gatun dam was
,,bking and that Subterranean Lake
AZ been discovered under the canal,
= an event that was expected, a re-
0o,t has been made to the authorities
a. washington which, 1t Is hoped, VIII
dIspel any apprehension.
A portion Of this toe" on the up
..ypsm end Of the dam sank about
sorty feet on Nov. 81. During several
weeks prior to this date slide under
the high trestle of the relocated Pan
ANA railroad at Gatun made neces-
sarv the dumping of an additional
quantity Of rock before the roadbed
was brought up to grade. On Nov. Is
the .Chagres river flooded the tracks
At Gatun. At the same time the ru-
NOR Of having discovered a subterra-
mean lake on the site Of Gatun dam
and beneath 1t came out. The report
says in part:
THE purpose of the dam at Gatun
d to impound the waters Of the
Chagres ian artiiciaD lake that viii
form in the valley of the Chagres riv-
er. This dam will extend from one
ridge Of hills west across the valley
. to the ridge on the hills east and will
be one and half miles long. At the
extreme east end the locks are being
built through a small hill on which
abuts the dam. The dam itself is di-
vlded into two parts, from the site of
the locks to the spillway, the other
from the spIllway to the hills west.
The splllway will be located through
q small hill that rises I'm the middle
Of the dam. A temporary spillway
800 feet wide, which will let the
Chagres flow during the construction,
Is completed and concrete laid there
early in January. There are three old
channels running through the dam
sIte
The plan for constructing the dam
Is to pump sand and clay upon the
site selected until the hill is 1876 feet
above sea level and LOO feet wide
across the valley. This sand and clay
have been found in large quantities
down the Chagres valley, convenient
to the site, and have proved to be
good material for a dam. The dam
will be made by suction dredges,
which will pump the material mixed
with water upon the site, and the wa
ter running off will leave a closely
homogeneous material. For the pur-'
pose Of adding weight to the dam and
to prevent material from sliding north
and south, as a great mass Of earth
Is likely to do, two walls, or toes, are
being built across the valley.
The north or downstream toe is
composed Of rocks and earth taken at
the site Of the locks. The south or
upstream toe is composed Of hard
rock taken from the cut at Bias Obs
20. The ridge of Bias Obispo rock is
tnlrty feet broad at the top and when
completed will be sixty feet high. It
mas reached that height in one place
and has one to one and a half slope.
Between the north and south toes
SOOOOOO cubic yards of clay and sand
nom the Chagres valley will be pump
"a The object Of these toes Is to hold
me material Of the hydraulic III until
Ine water has drained on.
The rock wall Of the south toe has
Oeen extended to the spillway, closing
lne on channel Of the Chagres and
eaSt diversion beside the old French
sahai' the river finding an outlet
through the east diversion dug by the
french, The old French canal crosses
s1e Chagres at FIVE different places be-
tween Bohio and Gatun. and II Is
through that channel that the greatest
p.t. Of the Chagres flows to Gatun.
a snort distance above the dam the
Sseonciiio flows into the Chagres. The
Suuoing Of the toe forces the water OF
- GatuncillO and that OF the French
ei or canal to seek an outlet at
: gnt angle to its natural course, and
sas caused the fats south OF Gatun
" hooded when heavy rains occur,
tne diversion of the French canal
10y nOt wide enough to receive the
sSaauy Of water that flows down the
- 49, and foods the lower parts. The
. - water Of Nov. Is was simply the
s'ion OF what happened several
~ during this rainy season, food
ne mats Of Gatun on the south OF
~. snu 1t was unusually high, a. the
go lOse IN some places az much as
inches above the rails.
-. Isay between the foot Of the
-. MI and the spiIlway the old
~ $50 canal channel runs through
~ IN site, but IT has been closed By
=, usruetion Of the south toe. The
! 10 soft mud that had collected
- - bottom Of this channel for the
twenty years were not removed
-. ne construction Of the toe was