The Austin weekly statesman. (Austin, Tex.) 1883-1898, 1890-10-23
tract calls for granite.

J 1000 less than the engineers esti
mate for both upstream and down
stream faces to be of granite.
THE DAM.
The Colorado, above Austin, flows
in deep cut or canon worn in lime
stone rock. 1t is skirted by limstone
bluffs rising often to the height Of
one hundred and fifty feet above the
bed of the river, broken by the ero'
sion of tributary streams No extern
sive meadows or bottom lands exist
The situation permits the construc.
ton of high dam with but little
damage to private property. The
river, in its normal condition, occu.
pies but smlll part of the channe
in the rock. the remainder being oc
cupied by alluvial deposits to the
depth Of average high water. In
great floods the river spreads from
bluff to bluff.
The dam will be located two miles
above town on what is known as the
Breckenridge property.
The channel in the rock is here about
115O feet wide at height of sixty feet
above the summer level of the river.
The cross section of the channel is not
far from level on the bottom, and is
bounded by nearly perpendicular walls
of rock rising to the height of little
over sixty feet on the city side of the
river, and 124 or more on the other
side. The river bed proper occupies
not more than one-half of this width,
the remainder of this being alluvial
deposit, rising to the height of forty or
fifty feet above the river bed. The sit
uation here is admirably we'll suited to
the development of water power by
dam about sixty feet in height, the
perpendicular face of rock rising to
about that height, and thence reced-
ing from the river in gentle slope,
forming bench on which the canal or
feeder could be constructed, the allu-
vial strip of ground between the canal
and river furnishing sites for pumping
and power stations, and other estab-
lishments requiring power.
Its crest will be about eleven hun
dred and fifty feet in length. 1t is
to make it some sixteen
feet thick at the top, increasing down.
ward and spreading out in broad toe
or apron, to give the water horizon
tai direction, making its extreme
width at bottom about fifty feet. The
body and upstream face of the dam
to be made of granite-faced work with
close Joints, and the downstream face
and tee to be of granite, split to
regular shape and laid
with but q small amount of tooling.
The Gaping is to be of granite in as
large blocks as can be handled, work
ed to regular shape. The entire work
is to be laid in hydraulic cement.
The Colorado, at Austin, drains
some forty thousand square miles,
and of course, carries, at times, an
enormous flow of water. The high
est flood within the memory of the
people now living, was some forty
five feet above low water. This
would imply depth of sixteen feet
on the crest of the dam, and the
abutments should of course 60 to
that height. The other end is occu-
pied by an artificial bulkhead, called |
he gate house, containing the sluices
or drawing off the water. 1t is ex-
pected that the wash of the dam
during floods will carry away the
alluvial deposit for considerable dis
lance.
The canal will be excavated in rock
and will be about 300 yards long.
The pond formed by the dam will
extend some thirty miles up the river,
but its flow will cover very moderate
amount of cultivated property, and
therefore the land damages will be
quite light.
1t is proposed that the water for
city purposes shall be pumped to res
ervoir upon one of the hills near the
city. The pumps will be run by the
water power from the hydraulic canal.
This method of supplying the city is
practicable, and can be carried
out economically.
SOME HAPPY RESULTS.
The result of the construction of
the proposed dam, with its ponds of
pure water covering some eight square