15.6 Consequences
247
Since risk data are often highly uncertain, some people are likely to object that
data and engineering judgments are too divergent to trust. In addressing this issue,
several guidelines can be helpful (for more details, see Hance et al. 1987).
Based on the system map (Fig. 15.5) the following consequences are evaluated:
Dam 1A: Extensive damages to the town and town infrastructure, and tailings runout
to the river stream with river transportation mechanism.
Dam 1B: Full loss of the town and town infrastructure, and tailings runout to the
river stream with river transportation mechanism.
Dam 2: water flooding into the valley with inundation of the low areas of the town
and industries, and loss of service of transport infrastructures.
Dam 3: tailings runout blockage in the valley, then flooding in the low areas of the
town’s industries and loss of service of transport infrastructures.
Dam 4: (Sect. 11.2.1) damages in the mine perimeter, road failure, personnel safety,
mining infrastructure.
Interdependent failure of Dams 2 and 3: The combination of water and tailings
makes the tailings more fluid; important scouring occurs; wider areas are impacted
because of the combined volume and higher energy.
Based on the above and on the definition of consequences we delivered in Sect. 7.6,
and Chap. 12, the dimensions of the failure selected for this discussion are as follows:
PL physical losses
HS health and safety damages
BI business interruption
ED environmental damages
RD reputational damages, legal fines, public outcry (community outrage) damages
CR crisis potential
where:
PL = value of significantly damaged assets including third-party assets. The “cost
of the dam” will be excluded from this discussion. To include it we should understand
how the structure is insured and the discussion would expand beyond the scope of
this book.
HS = evaluation of the global potential health and safety cost using the WTP (see
Sect. 13.1.2) assumed in this discussion at 2.5 M$.
BI = for small failures the business interruption is evaluated in weeks or month
for the clean-up to take place and appropriate infrastructure replaced. However, for
catastrophic failure or a failure that will cause third-party casualties—i.e., failures
that will cause a crisis potential—the BI will be evaluated in years (including legal
shutdowns etc.) until the operation can reopen. Mount Polley (see Sect. 2.1) took two
years to reopen and Samarco (see Sect. 2.2) is still closed four years after the catastrophe. The resilience toward BI damage depends on the company that owns/operates
the failed dam. A company with a large portfolio of mines will be less sensitive to
the impact, capable of buffering against BI by increasing production at other sites,
hence the overall damage may be greatly mitigated. A company with a small portfolio of mines will receive the full impact from the BI of one dam. Thus, discussing the
247
Since risk data are often highly uncertain, some people are likely to object that
data and engineering judgments are too divergent to trust. In addressing this issue,
several guidelines can be helpful (for more details, see Hance et al. 1987).
Based on the system map (Fig. 15.5) the following consequences are evaluated:
Dam 1A: Extensive damages to the town and town infrastructure, and tailings runout
to the river stream with river transportation mechanism.
Dam 1B: Full loss of the town and town infrastructure, and tailings runout to the
river stream with river transportation mechanism.
Dam 2: water flooding into the valley with inundation of the low areas of the town
and industries, and loss of service of transport infrastructures.
Dam 3: tailings runout blockage in the valley, then flooding in the low areas of the
town’s industries and loss of service of transport infrastructures.
Dam 4: (Sect. 11.2.1) damages in the mine perimeter, road failure, personnel safety,
mining infrastructure.
Interdependent failure of Dams 2 and 3: The combination of water and tailings
makes the tailings more fluid; important scouring occurs; wider areas are impacted
because of the combined volume and higher energy.
Based on the above and on the definition of consequences we delivered in Sect. 7.6,
and Chap. 12, the dimensions of the failure selected for this discussion are as follows:
PL physical losses
HS health and safety damages
BI business interruption
ED environmental damages
RD reputational damages, legal fines, public outcry (community outrage) damages
CR crisis potential
where:
PL = value of significantly damaged assets including third-party assets. The “cost
of the dam” will be excluded from this discussion. To include it we should understand
how the structure is insured and the discussion would expand beyond the scope of
this book.
HS = evaluation of the global potential health and safety cost using the WTP (see
Sect. 13.1.2) assumed in this discussion at 2.5 M$.
BI = for small failures the business interruption is evaluated in weeks or month
for the clean-up to take place and appropriate infrastructure replaced. However, for
catastrophic failure or a failure that will cause third-party casualties—i.e., failures
that will cause a crisis potential—the BI will be evaluated in years (including legal
shutdowns etc.) until the operation can reopen. Mount Polley (see Sect. 2.1) took two
years to reopen and Samarco (see Sect. 2.2) is still closed four years after the catastrophe. The resilience toward BI damage depends on the company that owns/operates
the failed dam. A company with a large portfolio of mines will be less sensitive to
the impact, capable of buffering against BI by increasing production at other sites,
hence the overall damage may be greatly mitigated. A company with a small portfolio of mines will receive the full impact from the BI of one dam. Thus, discussing the