Canadian Dam Association Bulletin - Winter 2019 - 17

and how an overall failure could
progress. This is not original thinking. Consider the figures shown
on page 15, taken from the book
Operational Safety of Dams and
Reservoirs (2016, Hartford et al).
By diagrammatically showing the
inter-related functions of each component of a complex system such as a
spillway gate, one can systematically
consider what happens if any component fails. Figure 1, on page 15,
shows the physical components of
a spillway gate with their logical
relationships.
A similar approach for the Oroville
service spillway would result in the
diagram shown on Figure 2, also on
page 15. If each component were then
considered in view of the basic functional questions given previously, the
resultant tabulations for the spillway
slab and drains would likely have
looked similar to those given in
Figure 1. If such tabulations had been
required during technical reviews,
it is possible that the importance of
and the necessity for investigations
into the identified unknowns would
have been recognized long before the
service spillway failure.
Would it really have been that simple
to have caught the developing failure
at Oroville or is this just reliance on
hindsight? We will never know, but
this exercise clearly demonstrates that
thinking about basics before starting
on risk considerations can be very useful. In general, new ways of thinking
need to be explored.
Figure 4 lays out a suggested priority
scheme for any dam safety program,
starting with the basics and progressing through to the point where risk
and risk tolerances could be considered. There are a surprising number
of steps and learnings required prior
to opening up Pandora's risk box. Risk
considerations should be used to fine
tune what should already be a healthy,
robust dam safety system.
The various inadequacies that led
to the Oroville spillway failure were
allowed under what is still being considered as current best practice. There
are fundamental flaws to address;
however, without leadership that
Canadian Dam Association * Winter 2019

is not mired in the status-quo, real
change in our industry is unlikely.
The roles of the CDA and the owners,
regulators and consultants who

belong to this organization must be
defined in moving forward on this
fundamental issue of challenging
current best practice.
■

Figure 3: Oroville Spillway Physical Components With Associated Functional Questions.

Figure 4: Dam Safety Program Suggested Priority Scheme.
17



Canadian Dam Association Bulletin - Winter 2019

Table of Contents for the Digital Edition of Canadian Dam Association Bulletin - Winter 2019

Board of Directors
President’s Message
Looking Beyond Oroville: Where to From Here?
CDA’s Recent International Business Development Activities
CDA 2018 Conference a Great Success in Quebec City
CDA Conference Hosts Events for Young Professionals
CDA Bestows Two Life Memberships
Honouring the Industry’s Leaders
Election 2018 Report
Financial Report: CDA Breaks Even in 2017-2018 Fiscal Year
ICOLD Corner
CDA 2019 Conference: Call for Papers
Buyers’ Guide and Trade List
Canadian Dam Association Bulletin - Winter 2019 - intro
Canadian Dam Association Bulletin - Winter 2019 - cover1
Canadian Dam Association Bulletin - Winter 2019 - cover2
Canadian Dam Association Bulletin - Winter 2019 - 3
Canadian Dam Association Bulletin - Winter 2019 - 4
Canadian Dam Association Bulletin - Winter 2019 - 5
Canadian Dam Association Bulletin - Winter 2019 - 6
Canadian Dam Association Bulletin - Winter 2019 - Board of Directors
Canadian Dam Association Bulletin - Winter 2019 - President’s Message
Canadian Dam Association Bulletin - Winter 2019 - 9
Canadian Dam Association Bulletin - Winter 2019 - Looking Beyond Oroville: Where to From Here?
Canadian Dam Association Bulletin - Winter 2019 - 11
Canadian Dam Association Bulletin - Winter 2019 - 12
Canadian Dam Association Bulletin - Winter 2019 - 13
Canadian Dam Association Bulletin - Winter 2019 - 14
Canadian Dam Association Bulletin - Winter 2019 - 15
Canadian Dam Association Bulletin - Winter 2019 - 16
Canadian Dam Association Bulletin - Winter 2019 - 17
Canadian Dam Association Bulletin - Winter 2019 - CDA’s Recent International Business Development Activities
Canadian Dam Association Bulletin - Winter 2019 - 19
Canadian Dam Association Bulletin - Winter 2019 - CDA 2018 Conference a Great Success in Quebec City
Canadian Dam Association Bulletin - Winter 2019 - 21
Canadian Dam Association Bulletin - Winter 2019 - 22
Canadian Dam Association Bulletin - Winter 2019 - 23
Canadian Dam Association Bulletin - Winter 2019 - CDA Conference Hosts Events for Young Professionals
Canadian Dam Association Bulletin - Winter 2019 - 25
Canadian Dam Association Bulletin - Winter 2019 - 26
Canadian Dam Association Bulletin - Winter 2019 - CDA Bestows Two Life Memberships
Canadian Dam Association Bulletin - Winter 2019 - Honouring the Industry’s Leaders
Canadian Dam Association Bulletin - Winter 2019 - 29
Canadian Dam Association Bulletin - Winter 2019 - 30
Canadian Dam Association Bulletin - Winter 2019 - 31
Canadian Dam Association Bulletin - Winter 2019 - Election 2018 Report
Canadian Dam Association Bulletin - Winter 2019 - 33
Canadian Dam Association Bulletin - Winter 2019 - Financial Report: CDA Breaks Even in 2017-2018 Fiscal Year
Canadian Dam Association Bulletin - Winter 2019 - 35
Canadian Dam Association Bulletin - Winter 2019 - 36
Canadian Dam Association Bulletin - Winter 2019 - 37
Canadian Dam Association Bulletin - Winter 2019 - ICOLD Corner
Canadian Dam Association Bulletin - Winter 2019 - CDA 2019 Conference: Call for Papers
Canadian Dam Association Bulletin - Winter 2019 - 40
Canadian Dam Association Bulletin - Winter 2019 - Buyers’ Guide and Trade List
Canadian Dam Association Bulletin - Winter 2019 - 42
Canadian Dam Association Bulletin - Winter 2019 - cover3
Canadian Dam Association Bulletin - Winter 2019 - cover4
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