1. Water System Seismic Study and Emergency Response Planning
Cascade Water Alliance meeting
06/09/2017

2. Agenda Background Water systems and planning for seismic events
Current State
Seismic study
Emergency response
Establish “service level goals” after a major earthquake
Balance goals vs. available funding
Looking Forward
Plan short-term and long-term infrastructure seismic upgrades as part of Capital Improvements Program

3. Earthquake Hazards
Ground Shaking
Fault Rupture

4. Earthquake Hazards
Liquefaction

5. Earthquake Hazards
Landslide
Tsunami

6. Importance of Water Post-EQ
Fire fighting
Sanitation
Consumption
Water is an essential lifeline

7. Some Recent Earthquakes and Water System Impacts
Year
Magnitude
Impacts
Loma Prieta, Bay Area
1989
6.9
Northridge, So. Cal
1994
6.7
Kobe, Japan
1995
Christchurch, NZ
2011
6.2
Tohoku, Japan
9.0

8. Nisqually Earthquake - 2001
Magnitude 6.8, centered near Olympia, 32 miles deep
Minimal effect on SPU functionality
Approximately $4 million in earthquake related costs
Masonry Pool Engineered Fill Failure
12 Pipe breaks and 7 pipe leaks
500 Ft. Long, ½-Inch wide crack in Cascades Dam

9. Nisqually 2001 (con’t)
Tolt East Side Supply Line Junction Valve Station damage
SPU Admin Bldg (Dexter Horton) nonstructural damage
Eastside Reservoir floor cracks and roof damage
Operations and Control Center Damage

10. SPU History of Seismic Work
Working on seismic issues for several decades
Various studies
Seismic retrofits
Incorporation of then-current seismic standards into new facilities

11. SPU History of Seismic Work
Regional collaboration with other water utilities

12. Better Understanding of Seismic Risks in Puget Sound – 1990 vs. 2015

13. Better Understanding of Seismic Risks in Puget Sound – 1990 vs. 2015

14. Emergency Response Response depends on type of emergency
Can vary widely
Water system redundancies can help with response times
Triage based on available data
SCADA
Rapid post-disaster assessment from SPU crews, engineers
Calls from other utilities, customers
Other?

15. Pacific Northwest Earthquake Sources (Washington State Department of Natural Resources and USGS)

16. SPU Water System Seismic Study
Establish post-earthquake water system performance goals
Seismic vulnerability assessments of facilities and pipes
Balance performance goals against cost of upgrades
Develop short-term (20 year) and long-term (50+ year) plans
Integrate plans into Capital Improvement Program

17. Balancing Performance Goals and Seismic Improvement Needs
Consultant Recommendations
Cost Considerations
This approach is typical of other water utilities
Post-Earthquake Performance Goals
Cost to Achieve Performance Goals

18. Stakeholder Input is Critical to Developing Performance Goals
Public/Direct Service Customers
Water System Advisory Committee
Customer Review Panel
Surveys
Wholesale Customers (Operating Board, Cascade Water Alliance)
City Leadership
Mayor/Council
Fire Department
SPU
Emergency Executive Board
SPU Staff

19. Draft Performance Goals
Water supply for fire fighting
Water supply for critical facilities like hospitals
Water supply for retail customers
Water supply for wholesale customers
How long should it take to achieve these goals for what % of the water system?

20. What Kinds of Upgrades Will Be Needed?

21. Next Steps Proposed mitigation options
Review cost of options and see if performance goals need to be changed
Study complete in 2017
Use results to develop short-term and long-term seismic recommendations
Fold into rest of Capital Improvement Program

22. Questions/Discussion

23. Extra Slides to Follow

24. Loma Prieta (San Francisco) - 1989
M6.9 (epicenter 60 miles south/southeast of San Francisco)
Approximately 1000 watermain breaks
Water system damage mostly in areas of poor soils
Water outage durations usually less than a few days
Fire suppression water was an issue in Marina District
Marina District 1912

25. Northridge - 1994 M6.7 (previously unknown fault)
Over 1000 watermain breaks
Over 100 fires
Water system damage mostly in areas of poor soils
Outage durations over 8 to 13 plus days

26. Kobe (Hyogo-Ken Nanbu) – 1995 (M6.9)
Over 1700 Pipe Breaks Just in Kobe
109 Kobe Fire Ignitions Immediately After Earthquake (Another 88 in Surrounding Cities)
60 Days Plus for Restoration of Service
Earthquake
(January 17)
“Substantial” Restoration (March 18)

27. 2011 Christchurch Earthquake (M6.2)
1645 Watermain Breaks (February 2011 Earthquake) in Christchurch
Limited Number of Fire Ignitions
45 Days Plus for Restoration of Service
Most of pipeline system restored (end of March)
FEB 22
(Earthquake)
Water Treatment Restored (mid April)

28. Tohoku (East Japan) – 2011 (M9.0)
Water Systems of Over 180 Municipalities Affected
345 Fire Ignitions
45 Days Plus for Substantial Restoration of Service
Houses Restored
“Substantial” Restoration (74,000 Houses Without Water) – May 1
Houses Without Water
Earthquake (March 11)
Sendai Pipe Breaks (red dots)

29. SPU Seismic Mitigation Program History
Seismic Reliability Study of the Seattle Water Departments Water Supply System (Cygna Energy Services, 1990)
Earthquake Loss Modeling of the Seattle Water System (Kennedy Jenks Chilton/USGS, 1990)

30. SPU Seismic Mitigation Program History (continued)
SPU Seismic Upgrade Program (e.g., OCC, Myrtle Elevated Tanks, Barton Standpipe, etc.)
Performance of Water Supply Systems in the February 28, Nisqually Earthquake (system post-earthquake hydraulic modeling, Water Research Foundation, 2008)
Picture of SPU upgrade such as myrtle elevated tanks goes here

31. What’s Changed (since 1990)
Active surface faults identified throughout Puget Sound region (e.g., Seattle Fault, South Whidbey Island Fault, Tacoma Fault, etc.)
Migration from 10% probability of exceedance in 50 years (475 year return interval) design earthquake to 2% probability of exceedance in 50 years (2475 year return interval) design earthquake

32. What’s Changed (since 1990 - continued)
Earthquake Experience (e.g., Northridge, Japanese, Chilean and New Zealand events)
Potential for mass availability of earthquake- resistant pipe in U.S.

33. Post-Earthquake Water System Performance Goals
Define water availability and water service restoration time after an earthquake
Purposes
Establish acceptable water system post-earthquake performance
Define seismic program objectives
Provide others with expected system performance so they know what to expect and prepare for

34. SFPUC Performance Goals
“The basic “Level of Service” criterion shall be to deliver winter day demand (WDD) of 215 million gallons per day (MGD) (February 2030 demand) within 24 hours after a major earthquake.
Deliver WDD to at least 70% of SFPUC wholesale customers’ turnouts within each of the three customer groups (Santa Clara/Alameda/South San Mateo County, Northern San Mateo County, and City of San Francisco).
Achieve a 90% confidence level of meeting the above goal, given the occurrence of a major earthquake.

35. EBMUD Performance Goals

36. Oregon Resiliency Plan Performance Goals