THE IRRIGATION AGE. 



77 



TAMING THE GREAT FREE BOOTER OF THE WEST 



A Remarkable Discussion of the Silt Problem of the Colorado River 



By F. C. FINKLE, CONSULTING ENGINEER. LOS ANGELES, CAL. 



Mem. Amer. Soc. M, E.. Assoc. Mem. Amer. Inst. C. E., Mem. Amer. Waterworks Assn. 



THE Colorado river is 

 by far the most im- 

 portant stream in the 

 Western part of the Unit- 

 ed States. Without mak- 

 ing comparison in detail 

 with any of the other 

 large rivers in the West, 

 suffice it to say, that 

 everything considered, in- 

 cluding climate and soil 

 conditions of the area 

 which may be irrigated 

 from this river, its value 

 is very much greater than 

 that of any other Western 

 stream. 



The Colorado river 

 has a drainage area above 

 Yuma of approximately 

 225,000 square miles, 

 which lies in seven states. 

 Its principal tributaries 

 are the Green, Grand and 

 Gila rivers. 



The amount of water 

 supplied by the Colorado 

 river has been gauged at 

 Yuma, Ariz., since the 

 year 1894, and in round 

 numbers the mean annual 

 discharge at this point is 

 equal to about 10,000,000 

 acre feet, sufficient water to cover 10,000,000 acres to 

 a depth of one foot. 



It is only within the last 20 years that the real 

 value of the Colorado river has become known to the 

 world. Previously, irrigation was practiced to a 

 greater, or lesser, extent from its tributaries in Colo- 

 rado, Utah and other states, drained by the upper 

 tributaries of the river. 



It is only since the discovery was made that the 

 great Imperial Valley in California could be irrigated 

 by the waters of the Colorado river that its real value 

 has become apparent. Investigations looking to pos- 

 sibilities of irrigating Imperial Valley were commenced 

 as early as the year 1891. 



I began at that time conducting an investigation 

 of the lower Colorado river. Surveys to determine the 

 feasibility of diverting the Colorado river were made, 

 and reports were prepared, giving an approximate idea 

 of what might be accomplished. 



It was not until the year 1899 that sufficient finan- 

 cial aid was secured to begin actual work on the un- 

 dertaking. It has, however, been done by entirely new 

 people^-the first promoters having become discouraged 

 during the world-wide financial panic of 1893. 



In order to understand the situation on the lower 



A section of the Newcomb flume on the Huntley Federal project in 

 Montana. Courtesy Klauer Mfg. Co. 



Colorado, it is necessary 

 to draw a word picture of 

 the Imperial Valley and 

 its relation to the river. 

 The greater part of the 

 Imperial Valley is situated 

 at a considerable elevation 

 below sea level. The low- 

 est point is in the Salton 

 Sink, now known as Lake 

 Imperial, which is 287 feet 

 below sea level. 



The greater part of 

 the Valley in the United 

 States varies from sea 

 level down to the eleva- 

 tion of Lake Imperial. In 

 Mexico it rises to 24 feet 

 above sea level at Volcano 

 lake. There are other 

 tracts of desert land out- 

 side of Imperial Valley 

 proper, lying in the Unit- 

 ed States, and situated at 

 elevations ranging from 

 sea level to 100 feet above, 

 or slightly more. 



The present intake of 

 the main canal leading to 

 Imperial Valley is a little 

 more than 100 feet above 

 sea level, but the topog- 

 raphy is such that diver- 

 sions from it within the United States are not 

 practicable until a point near sea level is reached. 



It is interesting to consider historically the forma- 

 tion of the present topography in the Imperial Valley 

 and along the lower Colorado river. 



Where the river at present enters Volcano Lake 

 through the channel of Bee river, the elevation is 30 

 to 35 feet above sea level. The regular channel of the 

 stream, which has not been occupied by water below 

 the inlet to Bee river since the year 1911, passes over 

 a delta entering the upper end of the Gulf of Lower 

 California. At the present time the flow passes through 

 Bee river into Volcano Lake and thence through 

 Hardy's Colorado into the Gulf of California. 



Before the existence of the Imperial Valley the 

 Colorado river entered the Gulf of Lower California 

 at a point several hundred miles south from its upper 

 end, near the vicinity of Hanlon's Heading, where 

 the intake of the present irrigation system is located. 

 The silt carried by the water of the stream formed a 

 delta encroaching laterally, and further and further 

 into the Gulf, until it finally formed a dam entirely 

 across the Gulf, along that portion of it lying imme- 

 diately south of the International boundary line be- 

 tween the United States and Mexico. 



