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Dam Name:Prepared by: <br /> Location:Date: <br /> Breach Scenario: <br />National Weather Service Simple Dam Break Equation <br />Avg. Breach Width (ft) from previous sheet: <br />Time of failure (hrs) from previous sheet: <br />Height of water above breach bottom (ft): <br />Reservoir Surface Area at Failure (acres): <br />Discharge through spillways at failure (Qo, cfs): <br />Qb = Peak breach discharge plus discharge through spillways (cfs) <br />Qo = Discharge through principal and emergency spillways with water surface at failure level <br />Br = Avg. Breach Width (ft), typically 1 to 5 times height of dam <br />As = Reservoir Surface Area at with water surface at failure level (acres) <br />H = Height of water above breach bottom (ft) <br />Tf = Time to failure (hrs) <br />C = 23.4*As/Br <br />Factor (feet) <br />[H]12 59.48 1218 <br />[1.5H]18 39.65 1632 <br />[2H]24 29.74 1952 <br />[2.5H]30 23.79 2197 <br />[3H]36 19.83 2382 <br />[3.5H]42 16.99 2520 <br />[4.0H]48 14.87 2619 <br />[4.5H]54 13.22 2688 <br />[5.0H]60 11.90 2731 <br />Froehlich Eq. 96 7.41 2687 <br />Peak Breach Discharge:2731.4 cfs <br />GooseHaven Reservoir MJG <br />January, 2019 <br />C Qb (cfs) <br />Breach Width <br />Lafayette, Colorado <br />Dam Break <br />Peak Breach Discharge <br />12 <br />30.5 <br />0 <br />96 <br />1.42 <br />0 <br />500 <br />1000 <br />1500 <br />2000 <br />2500 <br />3000 <br />1 2 3 4 5Peak Breach Discharge (cfs)Breach Width Factor (#H) <br />Dam Breach Worksheet for Earthen Dams <br />January, 2019 <br />EXHIBIT E Attachment-B page 32 of 35