The Arizona sentinel., 1904-04-06
THE GREAT COLORADO RIVER

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 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. It is formed by the Junc- tlon of the Green and Grand rivers, rising in Colorado and Wyoming respectively, in re- gons of great precipitation, mainly Tn the form of snow. Only a small perecn tage Of the water yielded by the basin Of the Colorado has as yet been utilized for irrigation, and practically none for any other purposes. The obstacles gre many. Through most or its course this river and its tributaries flow at the bottom Of profound canyons, from which 1t Is impossible to divert them upon irrigable lands. The river elnergeS from it's canyon a short distance above the Needles-the cross ing of the Santa Fe Pacific railroad-and has a series of valleys which between ihlS polnt and the Mexican line aggregate about 5ut,OVO acres In this region the waters are heavily laden with sediment, which IS serious oD- siaclc 10 their diversion The grade of the river is so flat that diversion canal taken out at the rivers bed must have so slight a fall and so low velocity that II would quickly fill with sediment from the river For the same reason a canal must bc very long in order to command any considerable area Of land in the river valley
 TWO AND A QUARTER BILLION GALLONS 4
 MINUTE.
 Measurements of the flow near Yuma show that the river sometimes discharges mini- mum of about 5000 cubic feet per second. Its maxImunn discharge is unknown. but proba- bly exceeds one-half million cGbic feet per second As the river is supplied mainly by melting snows, Its season of hlgh water cul- minates in June and the low water season Is in the winter, when it's 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 if almost useless At low water the channel is so broad, shallow and changeable that boats arc continually running aground, sometimes being nearly a week in advancing ten or fifteen miles. In times or hlgh wafer the swift current greatly impalrs navigation. Wherever wagon transportation IS possible, this is preferred to the river.
 The chief obstacle to the utilization Of the waters of this basin arc: First, the great fiuctuation in discharge; second, the pauclty- of land that can be reached by them; third, the large quantity of sediment making lm- nractIcablc any diversion on a small scale.
 A comprehensive project is here presented, which, If upon investigation, is found im- 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, iu which this country is rich, is greatly ham, pered by the great cost of power and the lack of tran sportation, both important requisites fof the mining industry. The proposed plan will completely solve both problems.
 sUBTKoPIcAL CLIMATE.
 Allofthe land that can be irrigated from the lower Colorado may be regarded as hav-
  ing season for most products continues me year round-the req uircments for water, how ever, being greater in the summer season tlan in the winter. IL 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.
 It is probable that with proper regulation the Colorado river will be able to furnish continuous stream of water for industrial uses, varying from l0,OC0 cubic feet per second in winter 10 200O0 cubic 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 sum- cient to irrigate 2,000,00O 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 the valleys Of the lower Colorado consists of sandy flood plains subject to occasional inundations, and rough, gravelly foothills with soil unsuitable for cul- tivation. There are also considerable areas of sand dunes, and some tracts rendered bar ren by alka!i. All these 1t 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 d series of reservoirs on the Colo rado river by the construction of high dams at numerous points where the topography is favorable 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 win 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 velocity sufficient to carry a 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 impractical ble height. Al any time, by opening the Sluice- ways of .he reservoir, the current of the river will quickly cut 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 eN- 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 10 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. It 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 artifcally fin some parts of Europe and Africa. With the deep, alluvial soil, Scmi-tropical climate, arid atmosphere, abundant water supply, and the possibility of fertiiiZing the fields every year without expense. it 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.