2013 EERI Annual Meeting Session: Modeling Resilience

1. Modeling Water System
Services and Seismic
Resilience
2013 EERI Annual Meeting
February 14, 2013
Craig A. Davis, Ph.D., P.E., G.E.
Los Angeles Department of Water and Power

2. WATER SYSTEM
PERFORMANCE AND SERVICES
 Provision of water services and the protection of life and
property are arguably the most important performances a water
system can achieve
Performance Description
Category
Water Services Provision of water services identified in following
slides.
Life Safety Preventing injuries and casualties from direct or indirect
damages to water system facilities; includes safety
matters related to response and restoration activities.
Property Protection Preventing property damage as a result of damage to
water system components; also includes preventing
water system damage.
This presentation will not address expected performance levels.

3. WATER SYSTEM RELATION TO
COMMUNITY RESILIENCE
 Resilience requires us to look beyond system damages
and reduced ability to perform
 We must clearly understand how system damages and
operational losses directly impact customers.
 What are the parameters we need to understand in
order to model water system resilience?
System Operation_
Typical Resilience
Model
(e.g., McDaniels et al.,
2008; Bruneau et al,
2003)
Time

4. WATER SYSTEM RELATION TO
COMMUNITY RESILIENCE
 Lets start by examining the actual water services
provided and how their recoveries may be quantified
 Show how these apply to actual earthquake damages in
a water system
 Relate to resilience concepts
 Community resilience
 Water system resilience
 Formulate basis for modeling water system resilience
 Relate to other lifeline networks

5. WATER SERVICES
 Service restoration will be presented in the
following categories:
Service Category Description
Water Delivery Able to distribute water to customers, but the water delivered may not meet water quality
standards (requires water purification notice), pre-disaster volumes (requires water rationing),
fire flow requirements (impacting fire fighting capabilities), or pre-disaster functionality
(inhibiting system operations).
Quality Water to customers meets health standards (water purification notices removed). This
includes minimum pressure requirements.
Quantity Water flow to customers meets pre-disaster volumes (water rationing removed).
Fire Protection Able to provide pressure and flow of suitable magnitude and duration to fight fires. In many
water distribution systems the minimum pressure required for fire protection is 20 psi (140
kPa), with flow quantities varying by neighborhood.
Functionality The system functions are performed at pre-disaster reliability, including pressure (operational
constraints resulting from the disaster have been removed/resolved).

6. QUANTIFYING SERVICES
 Services can be quantified by the ratio:
number of customers with service after the earthquake
number of customers having the service before the earthquake
 Calculation Methodology
 Take area(s) where services are not being met
 Count number of services (or people, businesses, etc) in area
 Calculation is relatively independent of system layout and operations
(except for Functionality)
 Functionality service estimates require full understanding of
systemic capabilities
 Restoration curves are plots of this quantification over time

7. CASE STUDY:
Los Angeles Water System
1994 Northridge Earthquake

8. LADWP OVERVIEW
 Largest Municipal Utility in USA
 Founded 1902
 Serves 4.1-million people
 712,000 water service connections
 1214-square kilometer service area
 Receives water from:
 4 aqueducts
 Local wells
 LADWP owns and operates the water and power
systems

9. 1994 NORTHRIDGE EARTHQUAKE
 January 17, 1994
 Magnitude 6.7 (Mw)
 Thrust Fault (blind/buried)
 Epicenter in Northern Los
Angeles
 Urban San Fernando Valley
 Millions of people impacted by
strong shaking
 ~670,000 residents in LA
without water
 Another 180,000 people in LA
had reduced pressure

10. Fault rupture
area
Primary damage
area

11. LA WATER SYSTEM DAMAGES
(damage @ 2 locations)
(damaged influent
(damage @ 3 locations)
(power loss, damage to south half)
 14 repairs to raw water pipes
60 repairs transmission pipes
and effluent lines)

(power loss) GHT (roof collapse)
 1013 repairs distribution
Area shown in Figure 2
Desoto
Reservoir STL
RTL
pipes
(power loss)
GTL
RoTL  200 service connection
TT ZT
repairs
CCT
 7 damaged reservoirs
BGT
Damaged Tanks
 1/2 treatment plant out of
BGT = Beverly Glen Tank
CCT = Coldwater Canyon Tank
service
Van Norman Complex
GHT = Granada High Tank
TT = Topanga Tank
Additional Damage
-High Speed Channel
 Lost power up to 27 hrs
ZT = Zelzah Tank - Bypass Channel
- Power Plant Tailrace
- LA25 (MWD connection)
 No outage at pump and
- LA35T (MWD connection)
- VNPS I Discharge Line
chlorine stations
- VNPS II Discharge Line

12. 1994 NORTHRIDGE EARTHQUAKE
L.A. WATER RESTORATIONS
100 Normal Service Level Quantity
Fire Protection
Delivery
_
Los Angeles Water Service (%)
80
Northridge Earthquake
Quality
60 Functionality
40
20
0
-1 t0 1 3 5 7 9 11 13
Time (days)

13. (damage @ 2 locations)
1994 L.A. DELIVERY
(damage @ 3 locations)
(damaged influent (power loss, damage to south half)
and effluent lines)
(power loss) GHT (roof collapse)
Area shown in Figure 2
Desoto
Reservoir STL
SERVICES
RTL
(power loss)
RoTL
GTL
TT ZT
CCT
BGT
Damaged Tanks
BGT = Beverly Glen Tank
CCT = Coldwater Canyon Tank Van Norman Complex
GHT = Granada High Tank Additional Damage
TT = Topanga Tank -High Speed Channel
ZT = Zelzah Tank - Bypass Channel
- Power Plant Tailrace
- LA25 (MWD connection)
- LA35T (MWD connection)
- VNPS I Discharge Line
- VNPS II Discharge Line
100 Normal Service Level Quantity
Fire Protection
Delivery
_
Los Angeles Water Service (%)
80
Northridge Earthquake
Quality
60 Functionality
7 DAYS
 159,434 service connection outages 40
 22% of all services 20
 ~670,000 residents 0
-1 t0 1 3 5
Time (days)
7 9 11 13
 All delivery service restored in 7 days
 Pipe repairs completed several weeks later

14. (damage @ 2 locations)
(damage @ 3 locations)
1994 L.A. QUANTITY AND
(damaged influent (power loss, damage to south half)
and effluent lines)
(power loss) GHT (roof collapse)
Area shown in Figure 2
Desoto
Reservoir STL
FIRE SERVICE RoTL
RTL
(power loss)
GTL
TT ZT
CCT
BGT
Damaged Tanks
BGT = Beverly Glen Tank
CCT = Coldwater Canyon Tank Van Norman Complex
GHT = Granada High Tank Additional Damage
TT = Topanga Tank -High Speed Channel
ZT = Zelzah Tank
F
- Bypass Channel
- Power Plant Tailrace
- LA25 (MWD connection)
- LA35T (MWD connection)
- VNPS I Discharge Line
- VNPS II Discharge Line
100 Normal Service Level Quantity
Fire Protection
Delivery
_
Los Angeles Water Service (%)
80
Northridge Earthquake
Quality
60 Functionality
8.5-9
 203,164 service connection outages
DAYS
40
 28% of all services 20
 ~850,000 residents 0
-1 t0 1 3 5
Time (days)
7 9 11 13
 All quantity restored in 8.5 days
 All fire flow restored in 9 days

15. 1994 L.A. QUALITY RESTORATION
January 17 January 18 January 21 January 21
January 17
8 PM 10 PM 10 AM 6:30 PM
100 Normal Service Level Quantity
Fire Protection
Delivery
_
Los Angeles Water Service (%)
80
Northridge Earthquake
Quality
60 Functionality
40
12 DAYS
January 22 January 23 January 26 20
January 27
2:46 PM 10 PM 3 PM 0
-1 t0 1 3 5
4:30 PM
7 9 11 13
Time (days)

16. 1994 L.A. FUNCTIONALITY
RESTORATION
Normal Service Level Functionality (normalized)
100
_
Los Angeles Water Service (%)
Final
Effectively
80 Fully Improvements
Restored
Northridge Earthquake
System
Restored Completed
Improvements (6 years)
(9 years) (18 years)
initiated 100 Normal Service Level Quantity
60 (3 years) Fire Protection
Delivery
_
Los Angeles Water Service (%)
80
Northridge Earthquake
Quality
Functionality
40 60
Delivery 40
Quality
20
Quantity 20
Fire Protection
0
-1 t0 1 3 5 7 9 11 13
Time (days)
0
t0
-1 1000 2001 3002 4003 5004 6005
Time (days)

17. OPERABILITY VS FUNCTIONALITY
 Operability is achieved once water delivery, quality, quantity,
and fire protection services are restored
 System is able to completely service customers at pre-disaster levels
 However, system may not be fully functional
 e.g., LA Water restored operability in 12 days after repairing 8 of 60
transmission line leaks.
 Functionality services describe the ability of a system to reliably
perform.
 A highly functional system can provide water delivery, quality, quantity,
and fire protection services prior to completing all water infrastructure
repairs
 Damage imposes constraints that do not allow the system to function
with its pre-earthquake performance and reliability
 e.g., LA Water restored functionality in 9 years after repairing all
necessary damaged facilities (some remaining damage deemed
acceptable).

18. OPERABILITY VS FUNCTIONALITY
100 Normal Service Level Quantity
Fire Protection
12 DAYS
Delivery
_
Los Angeles Water Service (%)
80 Operability
Northridge Earthquake
Quality
60 Functionality
Normal Service Level Functionality (normalized)
100
_
Los Angeles Water Service (%)
Final
Effectively
40 80 Restored Fully Improvements
Northridge Earthquake
System
Restored Completed
Improvements (6 years)
(9 years) (18 years)
initiated
60 (3 years)
40
6 to 9 YEARS
20
20
Delivery
Quality Functionality
Quantity
Fire Protection recovery
0
t0
-1 1000 2001 3002 4003 5004 6005
Time (days)
0
-1 t0 1 3 5 7 9 11 13
Time (days)

19. FUNCTIONALITY DEFINITIONS
AND MISUNDERSTANDINGS
Some accepted Functionality Definitions:
 Recovery time as the period necessary to restore water supply system
functionality to a desired level that can operate or function the same, close to,
or better than the original one Cimellaro et al. (2010)
 Restoration as the time when the infrastructure is completely repaired
Bruneau et al., (2003).
 Many have, and still do, incorrectly describe Functionality restoration for
water systems as 1 of the other services.
 e.g., LA has been noted to restore functionality in 7 days after Northridge
earthquake (Incorrectly defined)
 This was the Delivery Service and the system was not actually fully operable until
12 days.
 Functionality per above definitions was not restored until 6 to 9 years
 This misunderstanding is also applied to all types of systems, including
building systems
 This is not just a issue of semantics
 It is a core understanding needed to help define community and system
resilience

20. WATER SYSTEM AND
COMMUNITY RESILIENCE
 Community Resilience
 Directly related to system Operability restoration
 Community recovery can accelerate once system operability is
restored (not limited to water systems)
 Even when functional recovery trails by many years and
results in periodic outages
 Water System Resilience (or other systems)
 Directly related to Functionality restoration
 Systems remain vulnerable to outage until full functional
recovery is made
 E.g. Christchurch water and sewer systems
 Functionality recovery is critical for ensuring the community
recovery is complete and sustainable

21. ACTUAL SERVICE RESTORATION AND
ASSUMED SYSTEM RESILIENCE
 Water service restoration is generally assumed to meet only one
category (incorrect), to the contrary
 Water system resilience cannot be characterized by any single
water service category
 It is dictated by all five service categories and how they interact
with the regional community
 This illustrates how water system resilience modeling is more
complex than previously recognized
 To engineer a resilient community, this complexity must be
understood and implemented into the proper models
Normal Service Level Quantity
System Operation_
100
Fire Protection
Delivery
_
Los Angeles Water Service (%)
80 Operability
Northridge Earthquake Quality
60 Functionality
40
20
0
Time
-1 t0 1 3 5 7 9 11 13
Time (days)

22. FRAMEWORK FOR WATER SYSTEM
RESILIENCE MODELING
 Assess seismic hazards
 Model system hydraulic performance
 Identify system losses
 Estimate service category restoration
 Assess community impacts
 Model community resilience
 Estimate economic Business Interruption from water system operability
loss
 Identify, prioritize, implement seismic improvement measures
 Quantify service category improvements using resilience model
 Helps to justify and prioritize mitigation measures

23. ASSESSING SHAKEOUT SCENARIO
IMPACTS TO LA WATER SUPPLY
Facility Damage GIRAFFE
Los Angeles Fault rupture and shaking;
Aqueducts 18+ months to restore Cornell
Colorado River Fault rupture and shaking;
University
Aqueduct 15 months to restore
California Fault rupture and shaking; 4 Calif ornia
California
Aqueduct months West Branch, 12 Aqueduct s
Los Angeles
months East Branch Aqueduct s
Transmission main 150 repairs Elizabet h Tunnel Color ado R.
Colorado
Aqueduct
(Trunk Line)
Distribution pipe 2,700 repairs Los Angeles

24. SHAKEOUT SCENARIO, L.A.
EXAMPLE WATER RESTORATIONS
Delivery Fire
100 Normal Service Level
ShakeOut Scenario Event
H I
Quality
(%)
Los Angeles Water Service _
80 Quantity
A
30% Rationing (11 months)
G
60 Functionality 18 MONTHS
F
50% Rationing (3 months)
C A. Immediately after event (System Serviceability (SS) = 76%)
40
B. 1-day after event SS declines from pipe leaks (SS = 34%)
B
C. 2-days after event, open emergency storage reservoirs (SS = 42%)
D. SS declines for 1-week due to pipe leaks and fire fighting demand (SS = 20%)
E E. 1 to 4-weeks: improvement from pipe repairs and ground water pumping (SS = 25-30%)
20 D F. 1-month: Regional supplies are delivered (SS = 50%)
G. 4-months: California Aqueduct West Branch returned to service (SS = 70%)
H. 15-months: Colorado RiverAqueduct returned to service (SS = 100%)
I. 18-months: Los Angeles Aqueducts returned to service
0
-1 t0 1 3 5 7 9 11 13 15 17
Time (months)

25. SHAKEOUT SCENARIO, L.A.
EXAMPLE WATER RESTORATIONS
100 ShakeOut Scenario Event Normal Service Level
Los Angeles Water Service (%)
Fire
_
Quality
80
A
3 WEEKS
60
F Quantity
C
40
Delivery
B
Functionality
E
20
D
0
-0.25 t0 0.5 1.25 2
Time (months)

26. FURTHERING MODEL
DEVELOPMENTS
 Characteristics and inter-relations of the service categories can be
used to better manage and engineer resilience
 Case studies provide valuable information useful for improving
water system and community resilience models
 Strategies used to return services
 Service loss impacts on customers
 How water systems can restore operability in advance of functionality
services
 The information will allow restoration models to be developed
that will improve predictive capabilities for water service
restorations
 Leads to improves community resilience models
 Useful for other infrastructure systems
 Further work needed to quantify this

27. PRACTICAL RESILIENCE
APPLICATIONS
 There are many practical measures that help lead to resilient
water systems.
 2 on-going programs are highlighted here.
 There are many other examples from numerous agencies
 LADWP is implementing a pilot project to implement a Japanese
designed Earthquake Resistant Joint Ductile Iron Pipe.
 LADWP is installing an HDPE pipe inside the Los Angeles
Aqueduct Tunnel where it crosses the San Andreas Fault
 These are innovative solutions that improve Community
Resilience through improved water system operability and
functionality.

28. LADWP – Kubota
Earthquake Resistant Joint Ductile
Iron Pipe
Pilot Project

29. Comparison of Joint Structure
General Joint
General Joint Earthquake-Resistant Joint
Earthquake-Resistant Joint
（ Flexible （ Chain structure
Joint ） Joint ）
Rubber Gasket
Rubber Gasket Lock Ring
Spigot Projection
T-type NS-type
Expand No Expansion if Expand / Contract
lock joint used
Deflect Deflect
Lock

30. Earthquake Resistant Ductile Iron Pipe
LADWP Installation, January 2013

31. Los Angeles Aqueduct Elizabeth Lake Tunnel
Real Time Monitoring & HDPE Pipe Installation
GPS &
Seismographs each
side SAF
Real-time information
CISN Display
Rapid assessment of
water supply damage
W = 9.5’ Enhances regional
seismic monitoring
Slip:
3.5 m = 11.5’

32. Los Angeles Aqueduct Elizabeth Lake Tunnel
HDPE Pipe Installation
 HDPE Pipe
to allow water
flow after
fault rupture

33. Questions?