The Arizona sentinel., 1904-03-30
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. Ii is formed by the juno lion of the Green and Grand rivers, rising in Colorado and Wyoming respectively, Tn re- gionS of great precipitation, mainly In the form of snow. Only a small percentage or the water yielded by the basin or the colorado has as yet been utilized for irrigation, ana 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 it Is impossible to divert them upon irligable lands The river emerges from its canyon short distance above the Ncedles-the cross ing of the Santa Fe Pacific railroad-4tnd has series of valleys which between thls point and the Mexican line aggregate about 5eO,uV acres. In this region the waters are heavily laden with sediment, which is serious Ob- Stacle 10 their diversion The grade or the river is so fat that diversion canal taken out at the rivers bed must have so slight a fall and so low a velocity that 1t would quickly fill with sediment from the F1Ver. 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 A QUARTER BILLION GALLONS A
 MINUTE.
 Measurements of the flow near Yuma show that the river sometimes discharges mlnl- mum of about 5000 cubic feet per second. us maximum discharge is unknown, but proba- bly exceeds one-half million cubic Feet per
  melting snowS, it's 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 ffat-bottom, stern wheel boats, which sometimes even ascend to the mouth Of Virgin river. Its navigation, however is so difficult and precaTlous as 10 make it almost useless. At low water the channel is so broad, shallow and changeable that boats are continually running aground, sometimes being nearly a week in advancing fen or fifteen miles. In times or high water 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 are: First, the great auctuation in discharge; second, the paucity of land that can be reached by them thlrd, the large quantity of sediment, making i'm practicable any diversion on small scale.
 A comprehensive project is here presented, which, if upon investigation, is found 1m- practicable, will largely remove all or 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 requisltes for the mining industry. The proposed plan will completely solve both problems.
 sUBTKoPICAL 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
 
 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 Tn 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.
 It 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 int second 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 suff- 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 the valleys of the lower Colorado consists of sandy flood plains subject to occasional inun dations, 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 alkali. All these it is proposed to re which annually passes down the Colorado river.
 SERIES OF DAMS.
 The general plan here proposed is the pro- vision of series of reservoirs on the Colo rado river by the construction or 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 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 of the soil and will be the highest permissible with out involving destructive erosion. The fall Of inc Colorado river is so slight that reSer- ~yOirs of enormous capacity may be construct ed without involving dams of impracticabie height. At any time, by opening the slCice- ways of the reservoir, the current Of the river will quickly cut a channel through the de- posted sediment from the upper end of the a 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 1t 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. 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 artifcially 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 can be farmed the year round and several crops taken off annually, al acreage production being thus attained entirely without precedent in history.