CHAPARRAL. 15 
distributed by gravity ditches. The demand upon the underground 
water has, however, exceeded the supply, and the water plane has been 
lowered year by year. In 1870 flowing water could be obtained in 
the “ artesian basin,” while good supplies could be obtained from ad- 
jacent areas by pumping. The country developed rapidly, and about 
1888 the water plane began to show the drain upon it. The artesian 
area was reduced and the pumping plants had to draw from lower 
levels. After some seasons of heavy rainfall the water plane has 
risen, but with these temporary exceptions the flow has been lowered 
from 20 to 80 feet. 
The streams which rise in the National Forests and receive run-off 
from chaparral areas are: 
Cottonwood Creek. Santa Ana River. Santa Ynez River. 
Sweetwater River. San Gabriel River. Santa Maria River. 
San Diego River. Los Angeles River. Salinas River. 
San Ysabel Creek. Malibu Creek. Carmel River. 
San Luis Rey River. Santa Clara River. Sur River. 
Santa Margarita River. Ventura River. 
The average annual run-off from all these streams is approxi- 
mately 1,500,000 acre-feet, theoretically sufficient, allowing 3 feet 
per acre, for the irrigation of 500,000 acres. In some years the flow 
is much less than this, and at such times greater economy is prac- 
ticed. The population dependent upon this water supply was, ac- 
cording to the census of 1900, 340,228. It is estimated by the Bureau 
of the Census that, by 1910, this number had increased to about 
730,000, and it is reasonable to suppose that the future population 
will be limited only by the amount of water which can be conserved 
and made available. The city of Los Angeles has had to go more 
than 200 miles to the Owens Lake watershed for its supply, and in 
southern California it is recognized as imperative that every means 
should be taken to save for use as much as possible of the rain which 
falls upon the mountains. ‘To-day there is land in southern Cali- 
fornia which, without water or the prospect of it, is not worth 5¢ 
cents an acre, but which, with water upon it, would be worth as high 
as $3,000 per acre. 
Nearly all of the mountain canyons are narrow and have steep 
grades and offer no reservoir sites for the storage of flood waters. 
Moreover, the flood waters are so exceedingly turbid that the reser- 
voirs would soon be filled with silt. Only in such places as the 
Cleveland National Forest, where the topographic conditions are most 
favorable, have reservoirs been constructed. There five have been 
constructed, two are under construction, and eight other sites will be 
available when the increase in population makes their use neces- 
sary. Over all the watershed areas above these reservoirs the annual 
evaporation from an exposed water surface is greater than the rain- 
