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<br />. <br /> <br />HIGH HAZARD <br />High hazard classification is assigned when failure of the dam will likely <br />cause loss of human life. Use of the flood plain by occasional campers and <br />fishermen is not controlling for these analyses, since these individuals are <br />expected to be warned by rising waters and flee for their lives. However, <br />this process is judgemental, and the existence of a large established <br />campground adjacent to the stream, should be considered. The following <br />criteria identifies a high hazard situation. <br />Calculations show that the channel capacity at the critical <br />section (Qc) is much less than the peak of the routed <br />failure hydrograph (QR). Flow through occupied residential <br />and commercial developments is judged sufficient force to <br />move buildings off foundations. The product of depth times <br />average velocity around buildings is in excess of 12 or <br />available warning time is insufficient, and escape is not <br />possible. High ground is not easily accessible. <br />The question of warning is significant. Although flooding may eventually <br />inundate and displace homes adjacent to wide gently sloping channels, the <br />residents would be provided warning based upon initial low flows and escape <br />to high ground (Example: Lower Latham Failure, 1972). In contrast, in <br />confined channels where flood waters would rise rapidly, warning time may be <br />minimal and escape may be impossible even though high ground is available <br />(Example: Lawn Lake Failure, 1982), Again, development of debris darns in <br />littered channels would increase flow depths and aggravate flooding. <br /> <br />23 <br />