Oak Harbor Facilities PlanOak Harbor Facilities PlanOak Harbor Facilities PlanOak Harbor Facilities PlanCity Council MeetingCity Council Meeting

November 20, 2012November 20, 2012

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Tonight’s Agenda/Objectives

1. Review scope and purpose of Amendment 5 2. Present results of field work completed through

Amendment 5– Topographical SurveyTopographical Survey– Environmental Assessment– Geotechnical Boringsg

3. Summarize estimated cost impacts4. Gain direction from Council on next steps:p

– Resolution 12-33: Complete Facilities Plan for Windjammer Vicinity as defined by Resolution 12-17

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– Resolution 12-34: Expand Windjammer Vicinity to include adjacent property and complete Facilities Plan

Resolution 12-17 (August 14, 2012)

• Proceed with Facilities Plan based on Windjammer Vicinityj y• Minimize space impacts on Windjammer Park

to the extent possibleC ti bli• Continue public process:

– Define the best locationwithin the WindjammerVicinitVicinity

– Define layout and otherdesirable features basedon the final locationon the final location

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Amendment 5 Scope and Purpose

• Technical detail to help select the best locationTechnical detail to help select the best location(3 to 4 acres) for the new WWTP

• Field work including:g– Phase 1 topographical survey to establish

elevations and flood protection requirements– Environmental assessment to better define

permitting and wetland mitigation requirementsGeotechnical borings to characterize soils better– Geotechnical borings to characterize soils, better estimated design requirements and cost

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October 16, 2012 City Council Direction

• Include adjacent property (Freund property) in scope of Amendment 5

Does Freund property provide technical/cost advantages relative to Windjammer Vicinity?

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Amendment 5 Current Status

• Phase 1 survey work complete (Attachment 1)Phase 1 survey work complete (Attachment 1)• Environmental assessment completed based on

October 30, 2012 site visit (Attachment 2), ( )• Geotechnical borings completed on October 30

and 31 (Attachment 3)• Additional engineering analysis completed to

compare three sites– Windjammer Vicinity (Charrette)– Freund

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– Windjammer Vicinity (Alternate)

Field Work SummaryPhase 1 Topographical Survey

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100-Year Floodplain (El 12.5 NAVD 88)

1515

9

100-Year Fl d l iFloodplain12.5 feet

~7

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Regulations for Floodplain Development

• Orange Book (Criteria for Sewage Works Design, ’08)g ( g g , )– G2-1.5.2 Flood Protection: Locate unit processes

above the 100-year flood/wave action or adequately t t f 100 fl d/ tiprotect from 100-year flood/wave action

• Oak Harbor Municipal Code 17.2017 20 190(2) Nonresidential Construction: Locate– 17.20.190(2) Nonresidential Construction: Locate construction above the base flood elevation or floodproof structure to 1 ft above base flood elevation

– 17.20.190(3) Critical Facilities: • Construction permissible if no feasible alternative• Lowest floor > 3 feet above base flood elevation

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Lowest floor > 3 feet above base flood elevation

Summary of Flood Protection Requirements

• Portions (or all) of sites being considered lie within 100-year flood plain (12.5 NAVD 88)

R d l ti d d/ t t t 13 5– Recommend elevating grade and/or structures to 13.5– Additional protection for “critical facilities” (e.g. electrical)

• Southern portions of Windjammer Vicinity sites must be l d i l 3 f

p j yelevated approximately 3 feet

– Retaining wall or sloped fill• Existing grade at Freund property is an average of ~6.5 feetExisting grade at Freund property is an average of 6.5 feet

below 100-year flood elevation– Retaining wall/levee– Fill siteFill site– New/improved access to site is needed

• 100-year flood elevation [+12.5] more conservative than Mean Higher High Water (MHHW) + sea level rise [approx + 11 3]

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Higher High Water (MHHW) + sea level rise [approx. + 11.3]

Field Work SummaryEnvironmental Assessment

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Summary of Environmental Assessment

• Wetland ditches at both Windjammer (Charrette) and Freund sites• Federal, state, Oak Harbor permit approvals required for wetland

fill/b ff i tfill/buffer impacts• Windjammer (Charrette) Site

– Wetland ditch along southern boundary may be filled as result of projectg y y p j– Mitigation costs estimated between $150,000 and $275,000– Risk of delays and/or cost increases relatively low (limited tidal water

connection) • Freund Site

– Wetland ditches along boundaries would be filled as result of projectSite adjacent to mitigation wetland; portion may be filled for access– Site adjacent to mitigation wetland; portion may be filled for access

– Mitigation costs estimated from $400,000 to $800,000– Risk of delays and/or cost increases relatively high (tidal water

connection; impact to previous mitigation wetland)

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connection; impact to previous mitigation wetland)

Field Work SummaryGeotechnical Assessment

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Geotechnical Boring Site Plan

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Geotechnical Cross Sections

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Geotechnical Cross Sections

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Summary of Geotechnical Assessment

• Ground improvements needed at all sites• Dewatering shoring and flood protection will• Dewatering, shoring, and flood protection will

also impact cost• Sites to north, west and center of Windjammer j

Vicinity are preferred– Highest ground elevation

Sh ll t t till (25 t 30 f t)– Shallowest to till (25 to 30 feet)• Park site: deeper to till; additional flood control• Freund east sites most difficult/costly• Freund, east sites most difficult/costly

– Lowest ground elevation– Deepest to till (40+ feet)

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Deepest to till (40 feet)

Cost Comparison

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Windjammer Charrette ConceptConceptual Plan View (August 14 2012)Conceptual Plan View (August 14, 2012)

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Windjammer Charrette Concept Conceptual Site Section View (August 14 2012)Conceptual Site Section View (August 14, 2012)

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Total Project Cost ComponentsWindjammer (Charrette) Layout

$95

$100

j ( ) y

$93 5 (Total)

$7.6

$2.9

$85

$90

$93.5 (Total)

$83 0 (WWTP)

$75

$80

Cost (M

illions)

Outfall

WW Conveyance

$83.0 (WWTP)

$83.0$65

$70

Estimated

  Co eya ce

WWTP

$55

$60

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$50Windjammer (Charrette)

WWTP Project Cost ComponentsWindjammer (Charrette) Layout

$80

$90

j ( ) y

$83.0 (WWTP)

$2.1

$15.0

$60

$70$68.0 (Construction + Land)

$50

$60

Cost (M

illions)

Soft Costs (25%)

LandAcquisition

$65.9$30

$40

Estimated

  Land Acquisition

WWTP Construction

$10

$20

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$0Windjammer (Charrette)

Approximately 17% of WWTP Costs are “Variable” Based on Site

$80

$90

$5 2$60

$70$68.0 (Construction + Land)

$11.7(“Variable”) $5.2

$50

$60

d Co

st (M

illions)

Land Acquisition

Architectural Premium

Added Structural

Geotechnical Premium

$56.3 (“Fixed”)( Variable )

$56.3$30

$40

Estimated Wastewater/Effluent Piping

Sitework

Base WWTP

$10

$20

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$0Windjammer (Charrette)

Sitework is Largest Variable Cost Component

$2.1$11.0

$12.0$11.7 (“Variable”)

$1.6

$8 0

$9.0

$10.0

)

$1.7

$0.8

$6.0

$7.0

$8.0

d Co

st (M

illions)

Land Acquisition

Architectural Premium

Added Structural

$0.4

$4.0

$5.0

Estimated Geotechnical Premium

Wastewater/Effluent Piping

Sitework

$5.2

$1.0

$2.0

$3.0 44% Sitework

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$0.0

$1.0

Windjammer (Charrette)

Sitework Cost ElementsWindjammer (Charrette) Layoutj ( ) y

$6 0

$7.0

$5.0

$6.0

$5.2 Sitework$1.2 Site

$4.0

d Co

st (M

illions)

Allowance (Wetlands Mitigation)

Allowance (Flood Protection)

Allowance (Stormwater Mgmt.)

Allowances

$2.0

$3.0

Estimated

( g )

Allowance (Clear/Demo)

Base Sitework Estimate

$1.0

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$0.0Windjammer (Charrette)

Property Adjacent to Windjammer VicinityConceptual Plan ViewConceptual Plan View

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Property Adjacent to Windjammer VicinityConceptual Site Section ViewConceptual Site Section View

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Offsetting Costs for Alternate (Freund) PropertyRelative to Windjammer (Charrette) Layoutj ( ) y

Lower Cost Higher CostsLower Cost• Property acquisition

(Assessed value)

Higher Costs• Wastewater/effluent

conveyance• Demolition/clearing• Aeration basin structure

• Geotechnical• Sitework

– Flood Protection– Wetland Mitigation

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Sitework Cost Element ComparisonWindjammer (Charrette) & Freund Layouts

$6 0

$7.0

j ( ) y

Allowances increase due to

$5.0

$6.0

)

increase due to Flood Protection and Wetlands Mitigation

$4.0

d Co

st (M

illions)

Allowance (Wetlands Mitigation)

Allowance (Flood Protection)

Allowance (Stormwater Mgmt.)

$2.0

$3.0

Estimated Allowance (Clear/Demo)

Base Sitework Estimate

$1.0

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$0.0Windjammer (Charrette) Freund

Windjammer Alternate ConceptConceptual Plan and Perspective View (8/14/12)Conceptual Plan and Perspective View (8/14/12)

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Lower Costs for Windjammer (Alternate) LayoutRelative to Windjammer (Charrette) Layoutj ( ) y

Same Cost Lower CostsSame Cost• Property acquisition

(Assessed value)

Lower Costs• Aeration basin structure• Geotechnical

• Demolition/clearing• Wastewater/effluent

Geotechnical• Sitework

– Flood Controlconveyance – Wetland Mitigation

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Sitework Cost Element ComparisonWindjammer (Charrette) & Windjammer (Alternate)

$6.0

$7.0

j ( ) j ( )

Allowances decrease due to

$5.0

$6.0

ns)

decrease due to Flood Protection and Wetlands Mitigation

$

$4.0

ed Cost (Million

Allowance (Wetlands Mitigation)

Allowance (Flood Protection)

Allowance (Stormwater Mgmt.)

$2.0

$3.0

Estimate

Allowance (Clear/Demo)

Base Sitework Estimate

$1.0

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$0.0Windjammer (Charrette)

Freund Windjammer (Alternate)

“Variable” Cost Comparison for All Sites

$11.0

$12.0 $11.7$11.3

$10.1

$8.0

$9.0

$10.0

$6.0

$7.0

$8.0

Land Acquisition

Architectural Premium

Added Structural

G t h i l P i

$4.0

$5.0Geotechnical Premium

Wastewater/Effluent Piping

Sitework

$1.0

$2.0

$3.0

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$0.0

$

Windjammer (Charrette) Freund Windjammer (Alternate)

“Variable” Cost Comparison for All SitesEstimated Costs Shown in Millions ($)( )

Windjammer(Charrette) Freund

Windjammer(Alternate)

L d A i iti $2 1 $0 2 $2 1Land Acquisition $2.1 $0.2 $2.1

Architectural Premium $1.6 $1.6 $1.6

Added Structural $0.8 $0.0 $0.0

Geotechnical Premium $1.7 $2.6 $1.4

Wastewater/Effluent Piping $0.4 $0.8 $0.4

Base Sitework (Fixed) $4.0 $4.0 $4.0Base Sitework (Fixed) $4.0 $4.0 $4.0

Clearing & Demolition Allowance $0.2 $0.0 $0.2

Stormwater Management Allowance $0.4 $0.4 $0.4

Fl d P i All $ $ $Flood Protection Allowance $0.4 $1.3 $0.1

Wetlands Mitigation Allowance $0.3 $0.4 $0.0

Subtotal, Sitework $5.2 $6.1 $4.6

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Total Site Specific Items $11.7 $11.3 $10.1

Total Cost Comparison for All Sites

$90.0

$100.0$93.5 $93.1 $92.0

$70.0

$80.0

)

$11.7 $11.3 $10.1

$50.0

$60.0

d Co

st (M

illions)

Soft Costs

Outfall

Conveyance

$30.0

$40.0

Estimated Site Specific Items

Base WWTP

$10.0

$20.0

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$0.0Windjammer (Charrette) Freund Windjammer (Alternate)

Summary of Technical & Cost Differences

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Summary and Conclusions

1. Based on assessed value Freund site will likely be less costly to acquire

2. Based on technical field work, Freund site will likely have higher construction cost

Wastewater/effluent Conveyance– Wastewater/effluent Conveyance– Geotechnical– Flood Protection

W l d Mi i i– Wetland Mitigation3. Very little difference in overall cost between sites4. Means to reduce the cost of “variable” components will be4. Means to reduce the cost of variable components will be

considered regardless of tonight’s decision5. Freund site presents higher risk due to environmental

permitting and regulations for filling within the flood plain

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permitting and regulations for filling within the flood plain

Next Steps

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Paths Forward Based on Tonight’s DecisionRetain Windjammer Vicinity

Resolution 12-33

1. Complete draft technical chapters of

Expand Windjammer Vicinity (Freund)Resolution 12-34

1. Amendment 6: Collect community p pFacilities Plan

2. Develop phasing/financing plan

3. Final Public Open House/Council

yinput; compare locations using TBL+

2. Select final location/layout for WWTPwith public input (Q1, 2013)

Workshop (Early 2013)

4. Council resolution to submit draft plan(Q1 2013)

3. Complete draft technical chapters of Facilities Plan

4. Develop phasing/financing plan

Fi l P bli O H /C il(Q1, 2013)

5. Complete environmental documents for approval

6. Begin Preliminary Design

5. Final Public Open House/Council Workshop (Q2, 2013)

6. Council resolution to submit draft plan(Q2, 2013)6. Begin Preliminary Design

a. Final location & layout of WWTPwith community input

b. Equipment procurement

(Q2, 2013)

7. Complete environmental documents for approval

8. Begin Preliminary Design

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g y ga. Final layout of WWTP with community

inputb. Equipment procurement

Questions?

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