Breach Parameters

MacDonald and

Langridge-Monopolis (1984)

Froehlich (2008)

Volume Eroded

V_er

(m³)

$V_{er}=0.0261{\left(V_{out}\times h_w\right)}^{0.769}$

(earth fill)

$V_{er}=0.00348{\left(V_{out}\times h_w\right)}^{0.852}$

(rock fill)

Breach Width

B

(m)

$B_b=\frac{V_{er}-H_b^2\left(C{Z}_b+\frac{H_b{Z}_b{C}_3}{3}\right)}{H_b\left(C+\frac{H_b{Z}_3}{2}\right)}$

$B_{avg}=0.27K_o{V}_w^{0.32}{H}_b^{0.04}$

K_o = 1.0 for piping

K_o = 1.3 for overtopping

Breach Side Slope (H:V)

0.5:1

0.7:1 piping

1.0:1 overtopping