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<br /> . 80 <br /> ~. <br /> 70 <br /> ~ I ~INfLOW <br /> o 60 <br /> ",0 1,1 <br /> OZ <br /> zO <br /> c( ~ 50 I \ <br /> 3'" 1 I <br /> 0", , I <br /> IW <br /> I- 0.... 40 I I <br /> z>- 1 \ <br /> _W <br /> .W L I \: <br /> w~ <br /> ~ (,) 30 I Ii <br /> ..- . <br /> G ~ I I }" <br /> 5(,) 20 I <br />r I <br /> I / <br /> 10 / <br />t 0 <br />I 2. 25 2. 27 <br /> JANUARY 1969 <br /> <br /> <br /> <br />Figure 6.-lnflow and outflow hydrographs of Santa <br />Ana River at Prado flood-control basin. <br /> <br />hydrographs in figure 6 show the effect of the <br />Prado flood-control basin on the floodflows of <br />the Santa Ana River; the peak inflow to the <br />reservoir of 75,000 cubic feet per second was <br />Aduced by storage to such degree that the peak <br />'IlI!'l'utflow was only 5,800 cubic feet per second. <br /> <br />The debris basins in Los Angeles County <br />trapped an estimated 2 million cubic yards of <br />debris. Of the 61 debris basins only seven were <br />completely filled, and only three of those had <br />debris pass over their spillways into downstream <br />drains. The improved channels, in general. <br />contained the floodflows within their banks or <br />levees; theonly serious flooding associated with <br />such channels occurred on the streams tributary <br />to the upper Santa Ana River. Most of the <br /> <br />~ <br /> <br />storm-drain system in Los Angeles County was <br />not overtaxed; where flooding associated with <br />drains occurred, it was primarily due to the <br />drains beeoming filled with sediment and debris. <br /> <br />J <br /> <br />The system of storage and conveyance works <br />for flood control in Los Angeles County <br />prevented damage estimated at 5900 million; the <br />Prado flood-control basin prevented damage in <br />Orange County estimated at 5260 million' <br />improved channels throughout the remainder of <br />the report area prevented damage estimated at <br />$40 million. <br /> <br />Although $1.2 billion of damage was <br />prevented, losses were still heavy. The death toll <br />for the storm and flood of January 1969 was 92 <br />persons. and 10,000 persons were driven from <br />their homes. Of the 92 that died, 19 drowned, <br />12 were buried alive in mud and debris, 55 were <br />killed in storm-associated automobile accidents <br />four were killed in storm-associated plan~ <br />crashes, and two died of heart attacks brought <br />on by physical exertion connected with the <br />nood. Physical damage caused by the storm and <br />nood is estimated at $62 million. (Physical <br />damage refers to rehabilitation or replacement <br />costs of structures or facilities that were <br />damaged or destroyed. It does not include such <br />emergency costs as those associated with <br />evacuation or police work, nor does it include <br />such indirect costs as loss of income due to <br />interruption of commercial activities or <br />depreciation of property values in areas that <br />suffered damage.) Table 3 shows damage figures <br />for urban and rural areas, and for comparison, <br /> <br />Table 3.--Estimated physicai damage. in miilions of dollars. in the report area in March 1938 <br />and January 1969 <br /> <br />. March 1938 <br />Location <br /> - Urban Total <br />East of Los Angeles County____________ II 3 14 <br />Los Angeles County_________________ 25 2 27 <br />West of Los Angeles County______________ 3 2 5 <br />.Total for report area____________,__ 39 7 46 <br /> <br /> <br /> January 1969 <br />Urban Total <br />18 10, 28 <br />14 I 15 <br />12 7 19 <br />44 18 62 <br /> .'B9 <br />