CONTROL OF FLOOD WATER IX SOUTHERN CALlFORNL\ 425 



it. though there are occasional areas with a gravelly loam. In the 

 canyon bottom the wash shows much evidence of high-water action 

 in the past, and boulders, gravel beds, and piles of debris indicate the 

 high-water points of many floods. At the mouth of Haines Canyon 

 is a large debris cone which has been built up by the erosion from this 

 area, and on which a colony has been established. 



Storms and Flood of 1914. 



Since the area was burned over, in 1913, there have been two very 

 heavy storms, the heaviest known since the region has become so 

 heavily populated, and hence the most destructive in their efifects. The 

 first of these was from February 17 to 21, 1914. Most of the storm, 

 which amounted to 7.04 inches, came in ten hours, one hour having 

 1.49 inches or 21 per cent of the total storm. ^ The damage occasioned 

 was much greater than a storm of this character would have been 

 because of the saturated condition of the ground and the high-water 

 stage existing in the streams from previous rains. No precipitation 

 stations were located in the mountains at this time, but it is certain 

 that the fall was much greater than at Los Angeles, where the records 

 here used were taken. An isohyetal map- prepared by the Weather 

 Bureau for this storm gave the precipitation on this area of over 13 

 inches. 



After the storms the height of the flood waters of various streams 

 was measured and the maximum discharge per unit area computed 

 from the water-marks by engineers. Of all the streams so measured 

 Haines Can}on had the highest intensity, the maximum discharge being 

 calculated as 712 cubic feet per second per square mile^ and was the 

 only one in which cover conditions had been reduced to a minimum. 



This flood from Haines Canyon caused a tremendous amount of 

 damage. Breaking loose from the old channel, the stream threaded 

 its way through the suburban site, destroying a number of lots, swept 

 across orchards and meandered through vineyards and grain fields, 

 eroding and depositing according to the velocity, and causing damage 

 running well into the thousands of dollars. The roads were washed 

 out, school dismissed until the stream had subsided so that it was safe 

 for children to cross, and business was at a standstill. 



^ Data from U. S. Weather Bureau Station at Los Angeles. 



^ Ford, A. Carpenter : "Flood Studies at Los Angeles." Mo. Wea. Rev., 42 

 (1914), pp. 385-391- 



' F. H. Olmsted in Report of Board of Engineers Flood Control of Los Angeles 

 County, August, 1915. 



