Small Dam Sunny Day Breach Failure Question

[Anonymous]

Hello All,

I am relatively new to the dam breach analysis and wanted to verify the results of my model for a “sunny day” failure. The input parameters are summarized below:

Pond Depth = 16 feet
Dam Top Elevation = 2970 ft
Bottom Pond Elevation = 2954 ft
Dam Sideslopes = 2H:1V
Dam Top Width = 30 ft
8″ Outlet Spillway Pipe Invert = 2967.33 ft
Volume @ Spillway = 14.55 acre-feet
WSEL @ piping failure = 2968 ft
Failure Time = 0.32 hrs
Breach Sideslopes = 0.5H:1V
Breach Bottom Width = 43 feet

The output I got from HEC-RAS was a Peak Q = 921 cfs.

Does this sound or seem correct?

Thank you for your time,

[Scott Miller]

Consider doing calculations from a state or federal Dam Safety Office manual, to see if the results are on par.

The Washington Department of Ecology has a Dam Breach Calculation Spreadsheet.

[Author]

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