Frostburg mining journal. [volume] (Frostburg, Md.) 1871-1913, 1893-10-28
One of the Great Works for Jrrigating
Lands In California.

One of the Great Works for Irrigating
Lands IN California.
Over 1000 feet above the sea, and
nearly 5000 feet below the great peak
of San Jacinto, in Riverside County,
there has now reached the height of
40 feet what is probably the best built
dam in America says the Irrigation
Age. 1t is in Il very narrow gorge of
solid rock, and built of blocks of gran
ite of from three to five tons each, no
small stone being used. The spaces
between these are filled with rich con-
crete, mixed by machinery and rammed
into place by steel rods.
This makes Il monOlith of the whole
structure, with the advantage of hay
ing more f1eXibility than any other
dam of equal strength could have
Its factor of safety is very heavy,
and its peculiar construction will make
it as nearly earthquake-proof as it is
possible for a dam to be.
With stone of such size, it could stand
for long time a very ample overflow,
but an ample waSteway will be pro-
vided. 1t will be carried to a height of
$50 feet, where it will hold 5000, ,OOO.-
600 gallons 1t may be built still high
or if necessary Though so high, it is
not very expensive on account of the
gorge being very narrow for the first
100 feet.
The watershed is over 100 square
miles of as good mountain watershed
as there is in this part of the State. 1t
is all high mountain, with steep slopes
and an average rainfall of about forty
five inches falling in six months. When
the gate was shut Il few days ago one
storm filled it to depth of ninety feet,
making a lake some two miles long.
The lowest summer flow is enough to
balance the evaporation, while the
average will furnish a large amount
of spring and early summer water after
the lake is full.
This water will be used upon what
is called the mesa in the rich valley of
San Jacinto. In this valley are many
thousand acres of the richest land, and
30 artesian wells are there pouring
out over two thousand inches of water.
This will build up one of the most
prosperous settlements in the new
county, with quite town and alfalfa
fields and orchards on every hand.
On the west, and some twenty to
forty feet above the main valley,
where the artesian belt is, lie some
thirty thousand acres of bench land,
that with water is the finest of fruit
land, and upon which the arteSian
water cannot be taken.
Upon this the water from Lake He
NETT will be led by pipe and cement
ditch and tiume down the canyon with
fall of $500 feet in a few miles.
which will give power enough to run
electric roads and lighting plants. be-
sides considerable for manufacturing.
Upon this mesa or bench land the
company already owns some 5000
,Nf al,
distribute water. and it will undoubt-
cdly sell water to the adjacent lands
if the owners prefer to keep them in
stead of selling them to the company.
While considerable has been done here
in the past without any irrigation the
use of water so far SurpaSScS the best
results without it that the sale of all
the water they can reservoir is assured.
This type of dam was selected main
ly on account of its economy of cement,
The hauling of cement up Il long
mountain road was serious item. 1t
is much stronger than ordinary rub
bic masonry, less apt to crack under
any sudden shock and also heavier for
the same bulk of material.
Where a savage stream has to be
fought and there is any question about
the sutticiency of the waste way, it is
llt DcSI ~ pc VI u1ll IL lIlt lltdNdSt
of the rock will permit the getting out
of large blocks. The overflow cannot
tear them loose, nor can any ordinary
pounding of water at the base jar it
so as to injure the joints of the struc-
ture.
Its economy over rubble masonry will
depend upon the price of cement at the
work and upon the cleavage of the
rock, it being assumed that in the case
of ordinary rubble work wire rope car
riers would be used to deliver stone
into place.
With some rock the waste of stone
too small for this type of dam, yet
large enough for common rubble work,
might be great enough to overbalancc
the difference in the amount of cement
used. At all events this form makes
most safe and imposing piece of
work that will endure as long as the
hills in which the dam is so firmly
locked