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<br />hazard susceptibility are discussed below. Section 6.4 <br />recommends s?ecific applications for management tools, while <br />Section 6.5 recommends an a?proach to flood management. <br /> <br />Debris Basins and Detention Dams <br /> <br />Susceptibility: <br />Floods larger than basin capacity will cause <br />excessive discharges or dam overtopping. <br />Substantial filling of the basin by sediment <br />occurs during each flood. <br />Erosion of dam due to local channel formation <br />and migration can damage the structure. <br /> <br />Effectiveness <br /> <br />~ Dec~e-ase all major hazards eKce~t scour by <br />decreasing peak water anti sediment discharges. <br />May cause increased scour and channel cutting <br />downstream due to abrupt reduction in sediment <br />load. <br />Debris basins may reduce sediment load but not <br />significantly reduce peak discharge. <br />Detention dams attenuate peak sediment and <br />water discharges but do not permanently trap <br />either; total sediment deposition may not be <br />significantly reduced. <br />If the flood path migrates away from the basin <br />or dam, the tool is useless. <br /> <br />Public Acceptance <br />The public may consider these measures to be <br />unsightly and dangerous. <br />Costs are high. and are typically paid by <br />federal and state agencies. <br /> <br />77 <br />