The Parker post., 1912-12-14

SllIS lIOm CHe SCrodIn nave pfOuucou
most fertile soil. The amount of
silt deposited by the river is estimat-
ed to be sufficient to cover SO square
miles one foot deep with dry allu-
vial soil each year The enormous
! deposit which has been brought down
by the river and spread over this
delta, has apparently cut off in the
process of it's deposit the northern
md of the Gulf of California.
Arthur P Davis, Chief Engineer of
| the United States Reclamation Ser
vice, in a popular article ON the Colo
that on irrigated areas in southern
California, including cities, an in
habitant is supported to each eight
tenths of an acre. He writes as fol-
lows:
''On the above basis the irrigation
of 100000 acres from the lower
Colorado would support population
of 100000 people, or community
more numerous than the entire pop
states of the Union, or about the
same as that of the entire state of
California at present"
The Colorado river in its present
unregulated condition ranges in dis
charge at Yuma from about 1000
cubic feet per second to 10000.
| Without regulation during the year
1903 (Which was an average dry year,
with a discharge of 11,329,0OO acre
feet) the river could have sufficient
ly irrigated about 400 900 acres, has
ed on the assumption of a depth of
water annually applied of 51a feet,
which was the amount being used at
Yuma at that time. This provides
for seepage losses in transit through
the canals. If 100000 acres of land
were irrigated that year, in addition
to the normal flow of the stream in
it's low water period one million and
three-quarter acre-feet would have
had to be drawn from storage reser-
voirs. If 100000 acres were to be
| irrigated the necessary amount of
water required from storage reser-
voirs for the low water period of
the stream for the year 1903 would
have been 100000 acre7feet. This
would indicate that if adequate stor-
age were provided all the irrigable
lands along the lower Colorado river
| in the United States and In Mexico
could be supplied with water This
is exclusive of large areas in the
drainage basin of the Gila river and
the high mesa lands which border
the stream, where pumping would
have to be resOrted to. In the basin
of the Gila 100000 acres can now he
supplied with water from the RoOse-
welt reservoir and possibly half as
much more could be adequately serv-
ed from the regulation of the Gila at
San Carlos, the Verde at the Horse
shoe reservoir, and other sites, to
bring this area up to 100000 acres.
A search of the records of the Unit
ed States Geological Survey and of
the Reclamation Service shows that
storage capacity, within reasonable
limits, exists for the impounding of
8.50O,0O acre-feet of water. The gaug-
ings of the river at Yuma from the
year 1902 to the year 1909 inclusive
show a minimum discharge in 1902
of 100000 acre-feet and a maxi
acrefeet; an acre foot of water being
the amount necessary to cover one
acre one foot deep. If 400, 900 acres
were to be covered 51s feet in depth
in year, this would call for 7,70O,-
900 acrefeet, which the river could
have supplied in 1902, if regulated,
during that dry year. In the maxi
mum year 1909 the $500, 900 acre4feet
of storage would have been but 33
assuming that all of the reservoirs
would have been filled, which prob
ably would have been the case. The
building of these storage reservoirs
would not have obviated the neces-
sity for the construction of levees,
but it would have afforded consider
able relief
The month of greatest flood in
1909 was June, when the river reach
ed maximum flow at Yuma of 49,
500 cubic feet per second, yet in that
entire month the total discharge was
but 6.250,000 acre-feet, or less than
the aggregate capacities of the stor-
age reservoirs on the river. This
would indicate that the peak could
have been taken off the most viol-
ent floods.
The occasion for building storage