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

Components Studied

Natural Hazards AssessedEarthquakesLandslidesFloodsTsunamisVolcanic eruptionsWatershed firesSevere weather (wind, snow, ice)Climate change

Other Significant HazardsLandslides: threats to Spada and Chaplain

reservoirs and damsFloods: potential threats to above ground

transmission lines on Ebey IslandTsunamis: conflicting study results, potential threats

to above ground transmission lines on Ebey IslandVolcanic Eruptions: ash fall hazard, potential threat

to operability of Water Filter Plant

Anthropogenic HazardsThreats from insidersExplosionsFiresSabotageArmed attacksDisruption of IT,

SCADA, or communications systems

ContaminationForced entryCivil disorderCompromise of

personnelAirplane crash in

reservoir

Improvement ProgramsIP-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

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

IP 1 IP 2 IP 30

10

20

30

40

50

60

$ (Million)

≈ $1.3

≈ $38.0

≈ $47.7

Damages and LossesMajor Categories:

o Economic impacts on customers from loss of water service: by far the largest category!

o Damage to water system infrastructureMinor/Negligible Categories

o Secondary damages from failures of water system infrastructure

o Deaths and injurieso Water Revenue Loss

Scenario Damages and Losses

Benefit-Cost Results - 1As-Is Water Supply System $10,460,872After Mitigation: IP-1 $5,181,673

Annualized Benefits $5,279,199Present Value Coefficient 25.73Net Present Value of Benefits $135,833,801Cost Estimate: IP-1 $1,318,000Benefit-Cost Ratio 103.06

As-Is Water Supply System $10,460,872After Mitigation: IP-1 and IP-2 $752,383

Annualized Benefits $9,708,489Present Value Coefficient 25.73Net Present Value of Benefits $249,799,430Cost Estimate: IP-1 and IP-2 $39,317,000Benefit-Cost Ratio 6.35

As-Is Water Supply System $10,460,872After Mitigation: IP-1 and IP-2 $203,272

Annualized Benefits $10,257,601Present Value Coefficient 25.73Net Present Value of Benefits $263,928,061Cost Estimate: IP-1 and IP-2 $87,052,000Benefit-Cost Ratio 3.03

IP-1

IP-1 and IP-2

IP-1, IP-2 and IP-3

Average Annual Damages and Losses

Average Annual Damages and Losses

Average Annual Damages and Losses

Benefit-Cost Results - 2

After Mitigation: IP-1 $5,181,673After Mitigation: IP-2 $752,383

Annualized Benefits $4,429,290Present Value Coefficient 25.73Net Present Value of Benefits $113,965,630Cost Estimate: IP-2 Only $37,999,000Benefit-Cost Ratio 3.00

After Mitigation: IP-2 $752,383After Mitigation: IP-3 $203,272

Annualized Benefits $549,111Present Value Coefficient 25.73Net Present Value of Benefits $14,128,631Cost Estimate: IP-3 Only $47,735,000Benefit-Cost Ratio 0.30

Incremental for IP-2 after IP-1Average Annual Damages and Losses

Incremental for IP-3 after IP-2Average Annual Damages and Losses

Overall findings: HazardsEarthquakes have the greatest effect:

oLikely to meet goals for probable eventsoUpgrades needed to meet goals for

maximum events, estimated at ~$40 MMinor effects of other hazards relative to

meeting goals