158 



FORESTRY AND IRRIGATION. 



April, 



hills would not be subject to overflow 

 or encroachment, but those portions near 

 the river, if farmed, would have to be 

 protected, as in the case of the Missouri 

 and Mississippi bottoms. This, how- 

 ever, would only be necessary after the 

 outh'ing lands have become utilized, 

 and as further experience with the river 

 has developed its characteristics and the 

 necessities in the situation. 



The river water is always mudd}', the 

 percentage of silt being much greater 

 in the high spring and early summer 

 stages of the stream. Mr. H. Hawgood, 

 a civil engineer of Los Angeles, Cali- 

 fornia, has reached the conclusion that 

 the Colorado River carries enough silt 

 per annum to cover loo square miles 

 6}4 feet deep. He determines this both 

 by laboratory tests and by a long series 

 of records kept in the settling basins of 

 the pumping station at Yuma. 



The water is not of a very high grade 

 for domestic and irrigation purposes, 

 but it cannot be said to be a bad water, 

 and is of a higher grade than the water 

 of the Gila or the Salt Rivers. The hand- 

 ling of the silt in the canals is probably 

 the most serious problem in connection 

 with the irrigation from this stream. 



It is believed, however, that if the water 

 is conducted in the canals at as high or 

 higher velocities than it is in the river 

 at the point of diversion that this diffi- 

 culty might be avoided. 



Temperatures are high in summer, 

 frequently iio to 120 Fahr., but 

 probably they are no more severe than 

 those at Phoenix or Yuma, Arizona. It 

 is believed that the summer heat of the 

 Colorado Valley is no more oppressive 

 than that of the great central valley of 

 California, as at Bakersfield, Fresno, or 

 Red Bluff , or in the southeastern portions 

 of the United States. Palm trees were 

 observed growing at Parker, Arizona, 

 and the winter cHmate can be described 

 as semi-tropic. The growing season 

 would extend practically throughout 

 the year, and it would be possible to 

 cut from 6 to 8 crops of alfalfa annually. 

 During the expedition in January, 1902, 

 the weather was perfect for camping 

 without tents. 



The Colorado River, draining 225,049 

 square miles, and receiving its principal 

 water supply from Colorado and the 

 high mountains of Utah and Wyoming 

 from the melting snows, attains its 

 maximum annual flood stage, about 







VEGETATION ALONG THE LOWER COLORADO RIVHR. 



