CHAPTER XXVI. 215 



The works have reclaimed a tract of 7,000 acres from a desert to a 

 condition of high productive capacity. 



In addition to the greater works here described for the impounding 

 of water, many other worthy projects are outlined and contemplated 

 of a similar character, and it is felt that such development has only 

 fairly begun. 



It may be said that every canyon affording a living stream in 

 Southern California has been appropriated and its waters put to use, 

 while the springs and cienegas have been opened out and developed 

 by cuts, tunnels and bored wells. Not only this, but in all the im- 

 portant water courses issuing from the mountains, the underflow has 

 been sought after, and the subterranean supply brought out by exten- 

 sive systems of tunnels. This method of development is not confined 

 to the canyons, but tunnels have been driven into the sides of the 

 mountains to intersect ledges or across dykes that intercept the perco- 

 lating streams filtrating through the rocks. 



SUBTERRANEAN RESERVOIRS. 



On the three principal rivers of Southern California, the Los 

 Angeles, San Gabriel and Santa Ana, nature has formed subterranean 

 reservoirs of unknown capacity in the gravel beds formed by the 

 debris carried out from the mountains. These gravel reservoirs are 

 periodically filled, and the flow from them is constant and remark- 

 ably uniform. The Los Angeles river reservoir yields in this manner 

 from 4,000 to 5,000 miner's inches, all of which is diverted for the uses 

 of the city and the irrigation of adjacent lands. The San Gabriel 

 river reservor overflows in the narrow pass of San Bartolo, where the 

 stream goes through the Coast Range, and gives up in the aggregate 

 some 5,000 inches, which is used for irrigation in numerous ditches 

 in the Rivera and Downey district. 



The Santa Ana river reservoir is divided into two sections, one 

 of which supplies Riverside, Agua Mansa, and North Riverside, while 

 the lower division yields up its flow at the passage through the Coast 

 Range, whence it is diverted in canals to Orange, Tustin and Santa 

 Ana on the south, and PuUerton and Anaheim on the north side of 

 the river. 



The aggregate yield of these two natural reservoirs is in excess 

 of 10,000 miner's inches, and to their existence is due the prosperity 

 of the populous regions they supply. If these rivers flowed in rocky 

 beds from the mountains to the sea, they would be quickly exhausted. 



