The Arizona sentinel., 1904-10-12
THE GREAT COLORADO RIVER

The great Colorado river is the largest
stream, both in drainage area and discharge
that lies wholly within the arid portion OF
The United States. 1t is formed by the june
lion of the Greer and Grand rivers, rising in
Colorado and Wyoming respectively, in re-
gionS of great precipitation, mainly In the
form of snow. Only q small percentage Of the
water yielded by the basin of the Colorado
has vet been utilized for irrigation, and
practically none for any other purposes. The
obstacles are many. Through most of IT'S
course this river and its tributaries flow ut
the bottom Of profound canyons, from which
III Is impossible to divert them upon irrigable
lands. The river energies from its canyon a
short distance above the Needlcs-the cross
ing of the Santa Fe Pacific railroad-and has
q series of valleys which between tins point
and the Mexican line aggregate about 5000N0
acres. In this region the waters are heavily
Laden with sediment, which is a serious OBJ
Stacle to their diversion The grade of the
river is so fiat that diversion canal taken
out at the rivers bed must have so slight a
a fall and so low velocity that it would
quickly MI with sediment from the river.
For the same reason n canal must be very
long i'm order TO command any considerable
area of land in the river valley.
TWO AND QUARTER BILLION GALLONS A
MINUTE.
Measurements Of the flow near Yuma show
that the river sometimes discharges mini
mum of,about 5000 cubic feet per second. Its
maximum discharge is unknown, but prOba-
bly, exceeds one-half million cubic feet per
second AS the river is supplied mainly by
melting SHOWS, its season of high water cul-
inmates in June, and the low water season is
in the winter. when its sources are frozen.
The river is navigated more or less from its
mouth to the Needles by fiat-bottom, stern
wheel boats, which sometimes even ascend to
the mouth of Virgin river. Its navigation,
however, is so difficult and precariouS as to
nlake'it almost useless. At low water the
channel is so broad. shallow and changeable
that boats are continually running aground,
sometimes being nearly week in advancing
ten or fifteen miles. In times of high water
the swift current greatly impairs navigation.
Wherever wagon transportation is possible,
this is preferred 10 the river.
The chief obstacle to the utilization of the
waters of this basin are: First, the great
fiuctuation in discharge; second, the paucity
of land that can be reached by them; third,
the large quantity of sediment, making i'm
practicable any diversion on a small scale.
A comprehensive project is here presented,
which, if upon investigation, is found inn
practicable will largely remove all of these
difficulties, and will also greatly improve
navigation at all seasons of the year.
The development of the mineral resources,
in which this country is rich, is greatly ham,
pered by the great cost of power and the lack
of transportation, both important requisites
for the mining industry. The proposed plan
will completely solve both problems.
sUBTRoPICAL CLIMATE.
All of the land that can he irrigated from
the lower Colorado may be regarded as hav
Iag Semi-tropcal climate, where the grow
ing season for most products continues the
year round-the requirements for water, how
ever, being greater in the summer season than
in the winter 1T is here assumed that the
maximum use in July will be twice as great
as the minimum requirements In January;
and that stream with the maximum flow Of
two cubic feet per second i'll July, furnishing
about 1000 acre-feet per annum, viii supply
200 acres of land.
1t is probable that with proper regulation
the Colorado river will be able to furnish a
continuous stream of water for industrial
uses, varying from 1000 cubic feet per second
in winter TO 10000 cubic feet per second in
summer, in years of smallest discharge, al
lowing the great floods of wet years to sweep
TO the at present. This will be suffi-
cient TO irrigate 100000 acres OF land, and is
so far in excess of the requirements below the
Grand Canyon that no restriction need to be
put upon storage and diversion of waters
from the tributaries of the Colorado.
A considerable portion of tie valleys of the
lower Colorado consists of sandy flood plains
subject to occasional foundations, and rough,
gravelly foothills with soil unsuitable for Gull
tivation. There are also considerable areas
of sand dunes, and some tracts rendered bar
rem by alkali. All these it is proposed to re-
claim by impounding upon them the silt
which annually passes down the Colorado
river.
SERIES OF DAMS.
The general plan here proposed is the pro-
vision of a series of reservoirs on the Colo
RADIO river by the construction Of high dams
at numerous points where the Typography is |
favorable and where the possible storage is
large. All of these dams will be provided |
with large sideways through the base, in |
order that the stored waters may be entirely |
drawn off, together with their load of silt, |
whenever it is found desirable to do so. The |
reservoirs viii serve as settling basins for Sed |
iment. The dams Will also be utilized to
raise the waters into canals, for the double
purpose OF enclosing more irrigable lands by 1
such canals and of giving them a velocity |
sufficient to carry large amount of sediment |
IN suspension until it can be deposited upon !
the fields. The declivity given to the canals |
will depend largely upon the character Ofthe |
soil, and will be the highest permissible with
out involving destructive erosion. The fall of !
the Colorado river is so slight that reSer-
VOirS of enormous capacity may be construct |
ed without involving dams of mpracticable |
height. AT any tlme, by opening me Siulce-
ways of the reservoir, the current of the river
viii quickly cut a channel through the de-
posted sediment from the upper end of the
to the sluice gates; this being the
longest dimension and deepest part of the
will in all cases form an important
part of this storage capacity, and to this eX-
tent every reservoir can be permanently kept
clear of sediment without expense. With
this exception. each reservoir is expected TO
fill; when this occurs il is proposed
TO draw down the surface of the reservoir
20 to 30 feet, and to convert all
Of the reservoir site except the river channel
INTO irrigated farming land, and, if necessary.
construct another reservoir for storage pur-
poses higher up on the stream. This policy
will greatly increase the arabic area. 1t will
then be practicable, whenever desired, to
close the sluices and inundate all OF the agri-
cultural land in each filled reservoir and thus
FertiliZe it, as is naturally done by the river
Nile for the valley. This is done artificially
IN some parts of Europe and Africa. With
the deep, alluvial soil, semi-tropical climate,
arid atmosphere, abundant water supply,
and the possibility of fertiiizing the fields
Every year without expense. 1t is believed
hat such regions can be farmed the year
round, and several crops taken Off annually,
an acreage production being thus attained
entirely without precedent in history.