174 THE FORESTER. August, 



At the suggestion of Mr. Olmsted, Mr. Kinney then called upon Mayor Eaton, 

 of Los Angeles. His Honor said, in part : " I did not come here to-day to deliver 

 an address. Mr. Olmsted said there would be a possible niche to fill in, and so I 

 accompanied him. I cannot add much to what he has said. For the short time he 

 has been City Engineer he has made himself very familiar with this subject. 



" Mr. Olmsted spoke of the large gravel beds in the valley portion of the Los 

 Angeles River watershed, which he described as a natural underground reservoir. 

 In this connection I might say something as to the possibility of increasing the flow 

 of the stream by enlarging the saturated area in this mass of sand and gravel, which 

 extends along the base of the mountain shed on the north side of the valley. It is 

 of great depth and has an area of about twelve thousand acres, extending from the 

 mouth of two main canons to the river, with a surface inclination averaging about 

 seventy-five feet per mile. The plane of the saturated portion of this deposit has a 

 gradent of about fifty feet per mile, which leaves an average depth of at least one 

 hundred feet of dry material above the ground water, having a void capacity suffi- 

 cient to supply the present average normal run-off for six years without replenish- 

 ment. A very considerable portion of this area is wholly unsuited to agriculture, 

 as it consists of dry sand and boulder washes, which parallel the base of the moun- 

 tains, after emerging therefrom, and extending at intervals over a width of about 

 two miles. The floods of later years have been confined to one of these channels, 

 and I believe it quite practicable to divert the flow into a large number of channels 

 and thus secure a greater absorption during the periods of excessive rainfall. About 

 one year in five there is a large run-off which passes beyond the point where it is 

 available in maintaining the supply of this stream. 



"The western slope of the Sierra Madre and Coast range is very steep and few 

 suitably located surface storage sites are to be found, and in the absence of these, 

 the only method remaining for increasing the supply is to store the surplus rainfall 

 below the surface. We should commence where the rain first hits the ground, by 

 preserving our timber and plant growth, so that it will protect the soil from erosion 

 and retain it on the precipitous surface of our rainshed, which in reality is about 

 the only area in Southern California that yields anything to the run-off, with an 

 average precipitation. The western half of the Los Angeles River watershed con- 

 tributes little, if anything, to the waters during the normal flow of that stream. It 

 being principally valley, the usual rainfall is consumed by evaporation and plant 

 growth. 



"The importance of protecting the sources of our water supply is not generally 

 appreciated by the people. These scientific papers and discussions, while exceedingly 

 interesting to us, must be followed by an active campaign on lines that will engage 

 the attention of those with whom the solution of this matter rests. The average 

 citizen thinks that timber has value only for commercial use, and that brush is only 

 an incumbrance. Most of our mountain watershed in Southern California is below 

 the snow line, where the erosive effects from precipitation are greatest, and the brush 

 is the principal protection. 



"When the people have learned that existence in this country depends upon 

 the maintenance of the water supply, and that it is the chief factor in the develop- 

 ment of all our resources, there will be no difficulty in getting protection for the 

 forests and plant growth of our watersheds." 



Mr. T. S. Van Dyke then made some remarks on "Irrigation Problems." He 

 said in part : "The productive power of the United States has almost reached its 

 limits. A little more may be done by improved methods of agriculture. But if we 

 are to keep pace with the rest of the world in production we must take up irriga- 

 tion, not only in the West but in the East, because it is found that in the East the 

 product is increased as much in proportion by irrigation as in the West. It is hard 



