1. Goals & Objectives Objectives: Understand probable effects of natural and anthropogenic hazards Identify reliability & resilience projects Understand benefit-cost of projects Prioritize projects For Everett’s Water Supply System... Goal–Reliable water supply with resiliency

2. Components Studied

3. Natural Hazards Assessed Earthquakes Landslides Floods Tsunamis Volcanic eruptions Watershed fires Severe weather (wind, snow, ice) Climate change

4. Earthquakes Greatest threats: o Cascadia M7.5 Intraplate near Everett o Southern Whidbey Island M7.33 o Cascadia M9.0 Interplate o Duval M6.0 – for WFP

5. Other Significant Hazards Landslides: threats to Spada and Chaplain reservoirs and dams Floods: potential threats to above ground transmission lines on Ebey Island Tsunamis: conflicting study results, potential threats to above ground transmission lines on Ebey Island Volcanic Eruptions: ash fall hazard, potential threat to operability of Water Filter Plant

6. Anthropogenic Hazards Threats from insiders Explosions Fires Sabotage Armed attacks Disruption of IT, SCADA, or communications systems Contamination Forced entry Civil disorder Compromise of personnel Airplane crash in reservoir

7. Improvement Programs IP-1: enhance emergency planning, enhance mutual aid, complete additional studies to refine vulnerability assessment and finalize mitigation priorities IP-2: Upgrades for: Chaplain Reservoir and South Dam, Sultan River Diversion, Water Filter Plant, Transmission Lines 3 and 5, Reservoir 3, and other items IP-3: Upgrades for: WFP new flocculation basin, Transmission Lines 2 and 4, Reservoirs 2 & 6

8. Improvement Programs IP 1 - Emergency preparedness measures & studies to refine findings IP 2 - Upgrades to meet goals for maximum earthquake (2,475 return period) events IP 3 - Fully upgrade system for maximum earthquake (2,475 return period) events ≈ $1.3 ≈ $38.0 ≈ $47.7

9. Damages and Losses Major Categories: o Economic impacts on customers from loss of water service: by far the largest category! o Damage to water system infrastructure Minor/Negligible Categories o Secondary damages from failures of water system infrastructure o Deaths and injuries o Water Revenue Loss

10. Scenario Damages and Losses

11. Benefit-Cost Results - 1

12. Benefit-Cost Results - 2

13. Overall findings: Hazards Earthquakes have the greatest effect: o Likely to meet goals for probable events o Upgrades needed to meet goals for maximum events, estimated at ~$40 M Minor effects of other hazards relative to meeting goals