The Arizona sentinel., 1905-03-01
THE GREAT COL ORADO RIVER

Ht GKtAl GULURAUU RiVEH
 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. It is formed by the june 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 a small percentage of the water yielded by the basin of the Colorado has as yet Leen 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 at the bottom of profound canyons, from which 1t Is impossible to divert them upon irrigable lands. The river emerges 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 thIS point and the Mexican line aggregate about JO0,mI acres. In this region the waters are heavily laden with sediment, which is a serious ob- stacle 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 a velocity that Ii would quickly fill with sediment from the river For the same reason,a canal must be very long in 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 a mini mum of about 5000 cubic feet per second. Its maximum discharge is unknown, but prOba- bIy exceeds one-half million cubic feet per second. As the river is supplied mainly by melting snows, it's season of high water cul- inmates 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 10 the Needles by fiat-bOttom, stern wheel boats, which sometimes even ascend to the mouth of Virgin river. It's navigation, however, is so difficult and precarious as to make it almost useless. At low water the ohn al iS shallow chanUpa 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 to the river.
 The chief obstacle to the utilization of the waters of this basin are: First, the great fuctuation 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 small scale
 4 comprehensive project Is here nted, 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 V ill completely solve both problems.
 sUBTRoPICAL CLIMATE.
 All of the land that can be irrigated from the lower Colorado may be regarded as hav- sng a Scmi-tropical climate, where the grow ing season for most products continues the year rOund-thc req quirementS for water, how ever, being greater in the summer season than in the winter It is here assumed that the maximum use in July will be twice as great as the minimum requirements in January; and that a 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.
 ic r,ro olol1 Ia hot la the Colorado river will be able to furnish a continuous stream of water for industrial uses, varying fronel0,000 cubic feet per second in winter to 20G00 cubic feet per second in summer, in years of smallest discharge, d. lowing the great floods Cf "%t years to sweep to the ;.s at present This will be Suffi- c'-..V 70 irrigate 2,0O,OOO 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 Ofthe 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 cu- tivation. There are also considerable areas of sand dunes, and some tracts rendered bar ren by alkali All these it is proposed to re- claim by impending 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 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 velocity sufficient to carry large amount of sediment in suspension until it can be deposited upon the fields. The dcclivity 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 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 eases 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 1t 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. 1t will then be practicable, whenever desired, to close the suices and inundate all of the agri- cultural land in each filled reservoir and thus fartiliZe 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, Scmi-tTopical climate, arid atmosphere, abundant water supply, and the possibility of fertiizing the fields every year without expense. it is believed | hat such regions can be farmcd the year round, and several crops taken off annually, an acreage production being thus attained entirely without precedent in history.