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15 Risk-Informed Decision Making
Table 15.9 Annual probabilities of failure for the Dams in the portfolio evaluated using SLM and
Ore2_Tailings approaches
Dam
FoS
CAT. SLM
ORE2_Tailings
Annual pf
USA
ESA
static
USA/rapid
draw
down
ESA
Pseudostatic
per event
1A
n/a
1.61–1.68 1.18–1.23
return
1/475
1.4
n/a
≤10 −6
2.03 * 10 −3
to 5.6 * 10 −3
1.6
n/a
≤10
−6 to
2 * 10
−6
4.83 * 10 −3
to
1.16 * 10
−2
1.45
n/a
≤10 −6 to
1.2 * 10 −6
2.46 * 10 −3
to
6.71 * 10
−3
2.22
n/a
2.61 * 10
to
7.8 * 10 −5
2.99 * 10
−2
to
6.55 * 10 −2
1B
n/a
1.59–1.65
1.15–1.26
return
1/475
and
1/1500
1.4
n/a
≤10
−6 to
1.36 * 10 1.1 * 10
−3 to
1.03 * 10 −2
1.6
n/a
1.26 * 10
−6
to
4.03 * 10
−6
2.45 * 10 −3
to
2.07 * 10
−2
1.45
n/a
≤10 −6 to
1.79 * 10
−6
1.35 * 10 −3
to
1.23 * 10
−2
2.22
n/a
4.71 * 10
−5
to
1.74 * 10
−4
1.87 * 10
−2
to
1.05 * 10 −1
2
Rapid
drawdown
1.63–1.76
1.59–1.68
1.28–1.33
return
1/1,000
2.2
6.53 * 10
−6
to
5.12 * 10
−5
2.32 * 10
−5
to
9.65 * 10
−5
5.93 * 10 −3
to
1.31 * 10
−2
2.4
2.44 * 10
−5
to
2.64 * 10
−4
7.49 * 10
−5
to
2.64 * 10
−4
1.01 * 10
−2
to
2.32 * 10 −2
2.17
5.36 * 10
−6
to
4.36 * 10
−5
1.95 * 10
−5
to
8.3 * 10
−5
5.48 * 10 −3
to
1.23 * 10
−2
2.36
1.88 * 10
−5
to
1.22 * 10
−4
5.92 * 10
−5
to
2.16 * 10
−4
9.07 * 10 −3
to
1.86 * 10 −2
3
1.6
1.29–1.35
1.2
return
1/2,475
1.6
4.64 * 10
to
1.37 * 10
7.84 * 10 −3
Pseudo−5
−6
3.32 * 10
−6
−4
−3
(continued)