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Input Parameters for McIntosh Reservoir <br /> h w =depth of water above breach invert at time of failure = 4.2 m 13.9 ft <br /> h b = height of breach = 5.5 m 18.1 ft <br /> h d = height of dam = 5.5 m 18.1 ft <br /> V =volume of water stored above breach invert at time of failure = 3,194,366 m' 2589.6 ac-ft <br /> S = reservoir storage= 3,194,366 m3 2589.6 ac-ft <br /> Ko = 1.4 for overtopping, 1.0 for piping = 1 <br /> Z= breach side slope = 0.7 <br /> Breach Width Equations <br /> Froehlich (2008) <br /> B=0.27K0VWo.32hbo.o4 = 34.9 m 114.4 ft <br /> bottom width = 31.0 m 101.7 ft <br /> Von Thun and Gillette(1990) <br /> Cb =function of reservoir size = 18.3 m 60.0 ft <br /> B = 2.5hw + Cb = 28.9 m 94.8 ft <br /> bottom width = 25.1 m 82.2 ft <br /> USBR(1988) <br /> B =3(h w) = 12.7 m 41.8 ft <br /> bottom width = 8.9 m 29.1 ft <br /> Failure Time Equations <br /> Froehlich (2008) <br /> tf = 63.2(14/(0 b2))" = 1.82 hours <br /> Von Thun and Gillette (1990) <br /> tf =B/(4h w) (erosion resistant) = 1.70 hours <br /> USBR(1988) <br /> tf =0.011(B) = 0.14 hours <br /> B =average breach width <br /> V„ =volume of embankment material eroded <br /> tf =failure time <br /> Cb =6.1 m for V,N< 1230000 m3 <br /> Cb = 18.3 m for 1230000 m3< Vw<6170000 m3 <br /> Cb =42.7 m for 6170000 m3<Vw< 12300000 m3 <br /> Cb = 54.9 m for Vw> 12300000 m3 <br />