Durango semi-weekly herald., 1906-03-19
UNIQUE ENGINEERING.

Special interest attaches to the Yu-
ma project in Arizona and California.
one of the great national irrigation
works now well started, by reason OF
the unusual physical conditions OF
that section o. the southwest, and the
somewhat unique engineering prob
lens which are involved.
Physically and cllmaticalry the Col
orado delta Is slngularly Ike that OF
the Nile. Like the great river of Eg-
ypt' the Colorado river rises In far
distant mountains and cmptles
through great tidal flats into an In
land sea, Its valleys and climate nil
bearing out the likeness. The Colo.
rado Is one of the great rivers OF the
west. 1t drains an area of more than
225, 600 square miles and pours a tt,r.
bid river into the Gulf of California
for hundreds of miles 1t has cut Its
channel more than mile deep
through the plateaus. carving out
abyssmal canyons which are the most
wonderful In the world. In food lts
waters carry In solution millions OF
tons OF silt and detritus which for
ages the stream has deposited In the
sea. building up a broad delta through
which 1t flows on top OF a dyke 80
that Its normal channel IL elevated
considerably above the country on
either side. In time OF flood 1t spills
over its dyke innndating portIon
of Its valley The engineering works
involve dam across the river. can
ais on both sides of the stream and
an extensive system OF leyees to pro-
tect the lower lands from flooding.
Ihe dam known as the Lagunda Is
being constructed about twelve miles
above Yuma by New York contrac-
tor, and is notable as being the first
of Its type built In America. The
diamond drillers sought in vain for
bed rock formation in the channel
and finally the government decided
upon n structure of the East India
weir type patterned after the dams
built under similar conditions in In.
dia and Egypt by the English engl-
neers.
The Lagunda dam Will be 4.75O feet
long, 10 feet high, with a maximum
width of 2G5 feet and will contain
$4,000 cubic yards of loose rock.
1t VIII rest on n foundation of sand
and VIII weigh approximately SO0-
900 tons. The settling basin formed by
THIS structure Will be one mile VILE
aud ton miles long. To avoid the
enormous quantities OF silt carried by
the Colorado and whlch would quick
ly fll up the canals, the headgates
are so arranged as TO draw off only
the top foot of water into the canals.
Unprecedented floods during the
past year have emphasized the i'm
portnnce OF safeguarding the con-
struction OF the levces which are re-
quired to prevent inundation of val.
liable low-land areas The problem
Is complicated because of the fact
that the area to be irrigated Is In the
drainage basin of two important
streams, the ella and the Colorado
rivers, both subject to sudden and
tremendous floods.
The serious nature of the problem
which confronts the engineers will be
appreciated when II is known that
since the Initiation of the work the
ella has twice so changed its channel
and the topography OF the country
by cutting out In places and building
up in others that resurveys and
plans of structure nave been made
and remade by reason thereof The
leyees are now ready for construction,
but until they are completed the un-
certainty OF the behavior OF the Gila
renders 1t unwisc to let the work by
contract under definite plans as con-
tractors must necessarily be govern
ed by the conditions. and their bids
VIII be made accordingly. There is
urgent need OF haste.
The secretary OF the Interior rec
ognizing these facts and upon recon-
mendation of the board of consult
ing engineers who investigated the
situation. has ordered that the work
be undertaken Immediately by the
reclamation service by force OF ac-
count.