The Arizona sentinel. [volume] (Arizona City [Yuma], Yuma County, A.T. [Ariz.]) 1872-1911, 1905-10-11
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 o
| the United States. 1t is formed by the juno
ton 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 small percentage of the
water yielded by the BASIN of the Colorado
| has as vet been utilized for irrigation, and
practically none for any other purposes The
obstacles are many. Through most of its
| course this river and its tributaries flow al
the bottom of profound canyons, from which
1T Is impossible to divert them upon irrigable
| lands. The river emerges from its canyon q
short distance above the Needes-the cross
Ing of the Santa Fe Pacific railroad-and has
O series of valleys which between this point
and the Mexican, line aggregate about 500,O0C
acres. In this region the waters are heavily
| laden with sediment, which is serious OBJ
Stacle to their diversion The grade of the
| river Is SO fat that diversion canal taken
out at the rivers bed must have so slight a
a fall and so low a velocity that it would
quickly fill with sediment from the river.
For the same reason canal must be very
| long in order to command any considerable
area of land in the river valley.
rwo AND A QUARTER BILLION GALLONS A
MINUTE.
Measurements of the flow near Yuma show
that the river sometimes discharges q mini
mum of about 5000 cubic feet per second. Its
maximum discharge is unknown, but proba-
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 it's
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
make 1t almost useless. AT low water the
channel is so broad, shallow and changeable
that boats are continually running aground.
hQir odxyor r,oi
ten or fifteen miles. In times of high water
the swift current greatly impairS navigation.
Whereve- wagon transportation is possible,
this is preferred to the river.
The chief obstacle to the utilization of the
waters of this basin are: First, the great
huctuation 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
viii completely solve both problems.
sUBTRoPICAL CLIMATE.
All of the land that can be irrigated from
the lower Colorado may be regarded as hav-
ing a Semi-tropical 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 in July, furnishing
about 1000 acre-feet per annum, will supply
200 acres of land.
1t is probable that with proper regulation
the Colorado river will be able to furnish
continuous stream of water for industrial
uses, varying from 10000 cubic feet per second
in winter TO 10000 cnbic feet per second in
summer, in years OF smallest discharge, al
lowing the great floods of wet years to sweep
to the sea as at present. This will be suffi-
eient to irrigate 100000 acres Of land, and Is
so far iii 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 the valleys of the
lower Colorado consists of sandy flood plains
subject to occasional inundatiOns, and rough,
gravely foothills with soil unsuitable for cul-
tivation. There are also considerable areas
of sand dunes, and some tracts rendered bar
rem by alkai. 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 topography is
fa vorable and where the possible storage is
large. All of these dams will be- provided
with large sluicewayS 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 will 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
such canals and of giving them a velocity
sufficient to carry large amount of sediment
in suspension until 1t can be deposited upon
the fields. The declivity given to the canals
will depend largely upon the character of fthe
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 impracticable
height. AT any time, by opening the sluice-
ways of the reservoir, the current of the river
will quickly cut q channel through the de-
posted sediment from the upper end of the
reservoir to the sluice gates; this being the
longest dimension and deepest part of the
reservoir 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
gradually fill; when this occurs it is proposed
to draw down the surface Of the reservoir
permanently 20 to 40 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 filed reservoir and thus
fertilZe 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. it is believed
hat such regions car be farmed the year
round, and several crops taken off annually,
an acreage production being thus attained
entirely without precedent in history.