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ESTIMATION OF DAM BREACH PARAMETERS <br /> USING THE MACDONALD&LANGRIDGE-MONOPOLIS OR WASHINGTON STATE METHODS <br /> WITH ALL FAILURE TIMES ESTIMATED BY WASHINGTON STATE METHOD <br /> PROJECT: Fuchs Reservoir <br /> BREACH INPUT PARAMETERS: <br /> Select Embankment Type From Drop-Down Menu: EARTHEN(COHESIVE) <br /> Height of water over base elevation of breach(Hw)= 17.8 Feet <br /> Volume of water stored in reservoir at time of failure(V„,)= 240.9 Acre-Feet <br /> Reservoir Surface Area at H„,(A„)= 26.0 Acres <br /> Crest width of dam(C)= 8.0 Feet <br /> Height of breach from dam crest to base elevation of breach(Hb)= 22.6 Feet <br /> Slope of upstream dam face(Z„)= 2.6 Z(H):1(V) <br /> Slope of downstream dam face(Zd)= 2.0 Z(H):1(V) <br /> Breach side-slope ratio(Zb)= 1.0 Z(H):1(V) <br /> Piping Orifice Coefficient(Cr)= 0.70 Used To Calculate Peak Discharge Through Piping Hole <br /> Dam Size Class: Small Assumes Full Reservoir At Time of Breach <br /> CALCULATED BREACH CHARACTERISTICS: <br /> Breach Formation Factor(BFF)= 4287.486 <br /> Embankment Volume Eroded(Ve,)= 2044.3 Cubic Yards <br /> Average Dam Width(Wan)= 60.0 Feet(In Direction of Flow) <br /> Average Breach Width(B.„9)= 40.7 Feet <br /> Bottom Width of Breach(Bb)= 18.1 Feet <br /> Breach Formation Time(T,)= 0.56 Hours <br /> Storage Intensity(SI)= 13.5 Acre Feet/Foot <br /> Peak Breach Discharge(Op)= 6103 Cubic Feet per Second <br /> RESULTS CHECK: <br /> Average Breach Width Divided by Height of Breach(Bavg/Hb)= 1.80 If(Bavg/Hb)>0.6,Full Breach Development is Anticipated <br /> Erosion Rate(ER),Calculated as(Bavg/Tf)= 72.7 <br /> Erosion Rate Divided by Height of Water Over Base of Breach(ER/Hw)= 4.1 If 1.6<(ER/Hw)<21,Erosion Rate is Assumed Reasonable <br /> Bass I F,C—> <br /> 2 _ T <br /> 1 Zw ZE <br /> —p Bb Il <br /> Figure 1-Breach Variable Definition Sketch <br /> C -> <br /> . •. ... .. . ................. <br /> Z Za <br /> Hy 1 <br /> D 7 > <br /> A At„ <br /> —> D <— < L > <br /> Figure 2—Piping Hole Variable Definition Sketch <br /> MLM-WAv2 0 Fuchs.xlsm <br />