The herald., 1893-10-12
AN OVERFLOW DAM.
1T is TO BE THE HIGHEST IN
THE WORLD.
Immense Works for Two Irrigation
Districts IN tho San Joaquin
yslley-An AreA Of $780,
900 Acres.

San Francisco Gail: Stainslaus county
will have the highest overflow dam in
the world in about go days.
1t is called the La Grange dam. and Il
being constructed for the Modesto and
Turlock irrigation districts. Its location
is in the csfion of the Tuolumne river
three miles from the town of La Grange
Work on the project was commenced in
June, 1891, and has been pros ecuted
continuously ever since. A force OF 20C
men has been employed on the work
the total cost of which will be $500, 900.
The annals of engineering have hith-
erto recorded as the highest the Vyrnwy
dam. which retains the water supply for
the city of Liverpool. England. Its
height from base to summit 10 127 feet,
but the La Grange will be two feet
higher. Other celebrated dams, such
as the Bear valley in San Bernardino
county and the Sweetwater near San
Diego, are properly known as reservoirs,
and the protection OF their basins as re-
tanning walls.
The La Grange is being built by r. w.
Gorrill OF this city, and will be 800 feet
long on top, the plan being curved on q
radius OF 500 feet. 1t maximum height
above the foundation will be l27 feet 3
inches. The front face of the wall is
made to conform to the curve de-
scribed by the water In overlooking. and
to defect it into the basin in front of
the dam.
The dam is built of ''cyclopean rub
ble," and is model OF solidity. Huge
roobo xrasc froxx. 81 20 Qfore mara
hrst laid on the bottom. All their pro-
jecting pieces were cut off and fat but
rough surface was prepared for the lower
bed. Before being placed in the bottom,
all stones, whatever size, were scrubbed
and subjected to the action of numerous
jets of water under pressure OF rs feet.
The process OF construction WAS de-
scribed by R. w. Gorrill, its engineer,
as follows:
"a level bed was first prepared in the
rock and covered with Pinch layer of
cement mortar, which was beaten to
free it of air. A large stone was then
lowered into position by steam crane
and was beaten down into the mortar
by blows from heavy handmade. Other
large stones we're similarity placed, but
so as not to touch each other. The
spaces left between them were filled
with concrete, which was thrust into
the narrow spaces with Hampers.
''The work within the reach of each
crane was brought up from six to eight
feet before the crane was moved. In
each course the immense stones were
laid so as to bind with those in tie
course below. No horizontal joints
passed through the walls, as the top of
each course was left with projecting
stones and hollows, which permit it to
be we'll bound with the next course.
To make the back face thoroughly
water-tight, the vertical joints were
filled with mortar alone, and into this
broken stone was iorced."
The La Grange dam will distribute
water over territory embracing 276.0 900
acres. The Turlock district comprises
about 19S,000 and the Modesto district
$4,000. The water will flow over the
dam into two bitches. One will be 80
miles long and 100 feet wide. and the
other 2S miles long and 80 feet wide.
the waters of the Tuolumne river will
be banked up by the dam in the rocky
csfion, A lake will thus be formed four
miles long and half mile wide. An
idea of the solidity of the dam may be
gathered from the fact that at its base it
is III feet inches thick and that of
solid stone, forming an indestructible
barrier to the lake of water behind.
One of the largest grain growers Of the
state is Mr.. Hickman of Hick man, Stan
islaus county. He owns the Lide ranch,
comprising 10000 acres, all in wheat.
His lard is located near the dam, and
he believes that the distribution OF it's
waters will change the agricultural as
pect Of the section, which is now ex-
clusively devoted to the raising OF grain.
'What we have always needed in the
Central California counties," said Mr..
Hickman at the Palace yesterday, "is
the ability to produce diversity of
crops. We have had no rains since
March 9th last, and nothing but wheat
and barley can be raised. At the pres-
ent low prices for wheat farmers can not
make a penny. 1t is estimated that
Stanislaus county raises annually 1,000,-
600 tons OF wheat. The rate this year is
So ton less than two years ago. That
difference of Sc, ,000,0 900 just about repre-
sents the profit. so this years work has
been for naught.
Until 1891 we farmers were accus-
toned to receive 81. 80 to 81 &c. a bushel
for our wheat. In that year there was
big crop the world over, and we have
These Improbable seasons for grain
growers are liable to recur, but by hsv-
ing diversity of crops we farmers can
avoid being caught again. That is why
we, feel 80 jubilant over the La Grange
dam. The water will be turned into the
bitches on January 1st next"