Harbin, Chris

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Old Dominion University

Old Dominion UniversityODU Digital CommonsFebruary 23, 2018: Infrastructure Resilience Hampton Roads Sea Level Rise/FloodingAdaptation Forum2-23-2018Water Infrastructure Resiliency Planning for theCity of NorfolkChris HarbinFollow this and additional works at: https://digitalcommons.odu.edu/hraforum_19Water Infrastructure Resiliency Planning for the City of NorfolkChris Harbin, Water Production Manager, Department of UtilitiesN~ RFO[K UTILITIES Agenda1. City of Norfolk Resiliency Efforts2. Norfolk’s Water System3. Resilience of Norfolk’s Water System4. Next Steps5. ConclusionsCity of Norfolk Resiliency EffortsCurrent Challenge - 90% developed area- 12 feet above MSLHighest Relative SLR on East CoastApprox. SLR = 14 inches since 1930Sewells Point, VA 2.1----------------------------------------------Source:tlOM -0.3 ...... ----------------------------------------------1 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 Resiliency Efforts• 2015 Dutch Dialogues• 100 Resilient Cities (Rockefeller Foundation)• Resilience Strategy• Vision 2100• Flood Risk Study (with USACOE)• Ohio Creek Project• Water Infrastructure Resiliency PlanningOhio Creek Conceptual DesignNorfolk’s Water System Norfolk’s Water System – the Early DaysLake Prince constructionMoores Bridges mid-1870s3Norfolk’s Water System Today• Norfolk’s raw water sources are located throughout southeast VirginiaØ 5 Reservoirs in Norfolk and Virginia BeachØ 3 Reservoirs in Suffolk and Isle of WightØ 2 River Sources on Nottoway and Blackwater Rivers Ø 4 Deep Wells in Suffolk• Norfolk operates two water treatment plants: 37th Street and Moores Bridges with a combined capacity of 136 MGDIsle of Wight County Lake Burnt Mills \ Suffolk Lake Lake Smth Virginia Beach Resilience of Norfolk’s Water System How Can We Improve Resilience of Norfolk’s Water System?For over 140 years, the City of Norfolk has consistently treated and delivered drinking water to our customers.Recent events with widespread flooding:• 2009: Tropical Depression Ida and a Nor’easter• 2011: Hurricane Irene• 2012: Hurricane Sandy• 2016: Hurricane MatthewFlood and Wind Vulnerability Assessment and Hazard Mitigation PlanEvaluate vulnerabilities to the City’s water production infrastructure and develop adaptation measures to improve resiliency• Moores Bridges Water Treatment Plant• 37th Street Water Treatment PlantN~ RFO[K UTILITIES Risk Based EvaluationPhase 1ClimateAnalysisPhase 2VulnerabilityAnalysisPhase 3AdaptationAnalysisshould Norfolk prepare for?Climate Analysis What future climate and storm surge conditions Critical Flood Elevation Infrastructure Vulnerability Analysis What assets are at risk and what are they worth? Facil ity Vulnerabil ity Analysis What are the critical flood pathways and buildings at risk? Facilities and Infrastructure Needing Protection What protective measures should be implemented to reduce risk while balancing cost? Critical , Unprotected Infrastructure Final Steps Implement robust design standards and harden infrastructure through capital projects. Benefits of Risk Management ApproachØ Provides transparent, accountable and defensible business case for resiliency implementationØ Quantifies potential risks and impactsØ Facilitates analyses of tradeoffsØ Streamlines evaluation of multiple alternativesPhase 1:  Climate AnalysisCritical Flood Elevation• Established to evaluate what is at risk• The elevation to which assets must be protected may vary depending on funding agency requirementsshould we prepare for?Climate Analysis What future climate and storm surge conditions Storm Levels Considered• 100 Year Storm Recurrence: El 7.6 ft• City of Norfolk Building Code Ordinance: El 10.6 ft• Hurricane Storm Surge –Category 3:  El 13.7 ftWater Treatment Facilities At-Risk of Storm Surge Inundation Hurricane Storm Surge t N Moores Bridges WTP~ NJ.iftollc CHLOR~E CONTACT BAS~ MOORES BRIDGES WTP FLOOD POTENTIAL MAP - Elevation at 13.0 ft (NAVO 88) - Elevation at 14.0 ft (NAVO 88) Category 3 Storm Surge at 13.7 ft • Elevations on figure reference City of Norfolk datum I L 7 J Hazen I E] 37th Street WTP...... '• - Elevation at 13.0 ft (NAVD 88) - Elevation at 14.0 ft (NAVD 88) Category 3 Storm Surge at 13. 7 ft • Elevations on fig1Ke reference City of Notfolk datum ;:::;;-\ cl11 ___ _ - ... . ' I L, ! I i I J /h--0 Phase 2:  Vulnerability AnalysisHolistic understanding of magnitude of impact• Field Survey, Facility Database, Asset Database, and Storm Surge PlacardsFacil ity Vulnerability Analysis What are the critical flood pathways and buildings at risk? Facilities and Infrastructure Needing Protection Infrastructure Vulnerability Analysis What assets are at risk and what are they worth? '-. I Critical , Unprotected .... _._ _ _._ Infrastructure Investigate Flood Pathways and Establish Threshold Flood ElevationsElectrical Conduits and ManholesGratesDoorways & Windows AreawaysRollup DoorsTunnelsOther flood pathways: open process tanks, outfalls, storm drains and plant drains, wet wells, and interconnected buildings.Facility Analysis – Flood Pathway AssessmentHigh Pressure Pump Station Loading gate below grade Loading gate below grade -~ ... Flood Pathway Key: Non-Vulnerable :::1 ===:.:.:.""~.J> Vulnerable :::1 ======~> Critical Flood ElevationFigure 3.5: Different Elevations of a Facility Analysis Facility ! Flood Pathways .-------Asset Damage Elevation Cri1ical Flood Elevation :------- Flood Pathway Eleva1ion ..t===---- Vulnerable Flood Pathway Eleva1ion Facility Analysis – Field Survey30 25 00 20 00 0 > <( z ,!:'. 15 C 0 .... ro > ~ 10 w 5 - Vulnerable Flood Pathway Elevation - 100-Year Flood 100-Year Flood +3 Feet - category 3 Hurricane Storm Surge 'T1 OQ. C: ~ tD IJJ N 'T1 0 0 C. "'tJ Ill r+ :::r ! < !!! tD < Ill r+ o· :J Ill -0 ~ :E -i "'tJ 'T1 Ill ~-a: tD Ill Phase 3:  Adaptation AnalysisØ Prioritize processes/assets for adaptation Ø Discuss stakeholder objectivesØ Evaluate alternative adaptation strategies, including feasibility, costs and levels of protection provided Adaptation Analysis What protective measures should be implemented to reduce risk while balancing cost? Recommended Adaptation Strategies Final Steps Implement robust design standards and harden infrastructure through capital projects. Asset Criticality AssessmentHigh CriticalityImpact conveyance, disinfection, or power generationE.g.: Influent Motors, Effluent Pumps, Emergency Generators, Main Plant Feed and Transformers, Chlorination or UV EquipmentModerate CriticalityReduce level of service E.g.: Collectors for Settling Tanks, Sludge Pumps, Aeration Blowers Low CriticalityMinor or no impact to processE.g.: Odor Control Blowers and Scrubbers, Maintenance EquipmentMust be ProtectedCost-Benefit Driven DecisionTable P0-2: Moores Bridges WTP Vulnerable Facilities Summary Facility Vulnerable Critical ADE Vulnerable C ritica I ity FPE (NAVD 88) Assets(s) Rating (NAVD 88) Electrical 11.04' 12.04' Electrical s Distribution Distribution System System Generators 12.03' 12.03' Electrical Equipment s High Pressure 11.54' 10.04' High Pressure s Pumping Building Pumps Lake Wright Pump 9.74' 9.74' Pumps s Station Main Plant 10.53' 10.53' Electrical Equipment s Substation Main Plant 11.50' 11.50' Electrical Equipment 5 Switchgear Sodium 13.04' 13.04' Motor Control s Hypochlorite Center Solids Handling - 10.17' 10.87' Polymer Feed 3 Centrifuge Pumps Solids Handling - 10.50' 11.33' Transfer Pumps 4 Gravity Thickening Trim Pump 12. 77' 13.02' Variable Frequency s Building Drive Wash Water 12. 74' 14.24' Pump 3 Transfer Basin Asset Level Adaptation StrategiesIndividual Asset Multiple AssetsGenerator_____ __,A.._ _____ ..,. ( ' Elevate Equipment FloodProofEquipment Install Static Barrier Provide Eme~ncy Seal Building R iliency/Effectivene Low L w Cost L w C>oes not protoot ociuipment but facilitates rapid service recovery. Low Sandbag HI l Adaptation Recommendations• Sand Bags 0 Stop Logs • Permanent Flood Wall With Removable Stop Logs 0 Temporary Flood Wal l • Flood Wall & Earthen Berm Flood Vulnerability Mitigation for Moores Bridges WTP Water Production Infrastructure -Hazen ■--=:::::1--:::::i----■ Feet 0 80 160 320 HIGH PRESSURE Stop Logs • ·'4) ·• • ' ii I , ... J • "( Moores Bridges W-TP--" . . •' , -· ·-·-·-·-· • .. , I . . ' • I • • , 1. . Proposed Berm -~ ; -ELECTRICAL DISTRIBUTION SYSTEM ·-~~ ~ . . . - ~ -- / ~ Table 4.2: Moores Bridges WTP Individual Facility Mitigation Cost Comparison Facility Mitigation Alternative Mitigation Strategy Cost Electrica I Distribution Berm with flood wall $158,000 System Generators Temporary flood barrier $20,000 High Pressure Pump Permanent flood barrier with removable $53,000 Station stop logs Lake Wright Pump Station Permanent flood barriers with removable $12,000 stop log sections. Seal old entrance. Main Plant Substation Temporary flood barrier $50,000 Main Pia nt Switchgear Flood stop plate at one door, permanent $27,000 flood barrier with stop logs on other door Sodium Hypochlori te Sand Bag at doors below flood elevation $1,000 Bu 'lding Solids Handling - Flood stop plates and permanent flood $16,000 Centrifuge Building barriers with removable stop log sections Solids Handling - Gravity Flood stop plates and permanent flood $13,000 Thickening barriers with removable stop log sections Trim Pump Building Flood stop plates and permanent flood $16,000 barriers with removable stop log sections Wash Water Transfer Concrete improvements to raise curb $5,000 Basin around grates High pressure pump station with flood wallImplementationImplementationOverall cost of implementation of protective measures at Moores Bridges: $520KStorm Surge PlacardsEmergency Preparedness:These charts allow plant staff to quickly determine vulnerability to flood from approaching storms and begin implementing temporary adaptation strategies, such as sandbags.Storm Surge Guidance: Moores Bridges WTP If a storm surge advisory Is announced as part of a weather report, locate the forecasted surge level below. Protective measures should be taken for all locations at or below that level. Storm Surge Advisory" 16' 15' 14' 13' 12' 11' 11 0' Floodplain and elevations Cat3 Hurricane 13.7' .......... 100 yr. + 3' 10.6' ·········· 100 yr. 7.6 ' · Elevations and areas to be protected NAVO 88 Datum (to convert to City of Norfolk Datum, add 101.96') 17.0' 16.0' 15.0' 14.5' Flocculation-Sedimentation Basins #5 and 6, Front Office, Filter Basins-General, Flocculabon-Sedimentat1on Basins #2, 3, 4, 7, and 8 -- Low Utt Pump Station 14.0' -- Corrosion Inhibitor Feed, Basin 1 Equalization, Chemical Feed Bui lding 13.5' 13.0' -- Water Transfer Basin, Trim Pump Building, Sodium Hypochlorite System 12.0' Generators 11.5' Main Plant Switchgear, High Pressure Pumping Building, Storage Building 11 .O' Main Distribution Switchgear 10.5' -- Solids Handling-Gravity Th ickeners 10.0' -- Lake Wright Pump Station, Solids Handling-Centrifuge 9.0' 8.0' 7.0' HAzEN AND SAWYER Environmental Engineers & Scienlisls Next StepsNew Moores Bridges WTP Emergency EntranceIntegrating Asset Management and Resiliency Planning• An Asset Management Plan was completed for Moores Bridges in 2017• Asset Management and Resiliency Planning include similar evaluations of the same assets• Combining AM and Resiliency together reduces redundancy and improves capital planning• City of Norfolk will incorporate Resiliency Planning into Asset Management Program for City sewer and water infrastructureResiliency Planning DashboardFlood Event Critical Flood Elevation (ft) 100 Year 500 Year Category 1 Storm Category 2 Storm ■ Category 3 Storm Critical Flood Elevation is based on: 7.60 8.50 10.40 12.10 13.70 121 14 9 Criticality e High • Low Moderate Base Flood Elevation + 2' Sea Level Rise (SLR) + 1' Freeboard + 0.25' Subsidence Facility Replacement Cost Adaptation Cost Mitigated Risk Dewatering Building $314,835 $75,000 $239,835 Total Replacement Cost Total Mitigated Risk Benefit Cost Ratio Emergency Electrical $2,000,000 $150,000 $1,850,000 $5,184,735 $4,459,735 6.15 Pumping Station $2,405,000 $400,000 $2,005,000 Thickening System $464,900 $100,000 $364,900 Replace I Adapt Mitigated Risk High $285.000 High $2.458.235 Low Low Moderate Moderate Hazen ConclusionsResiliency Adaptation Requires Balance.Budget     ConstraintsSchedule ConstraintsEase of MaintenanceEase of ImplementationProtect              public healthProtect                   the environmentProtect infrastructureMeet permits and regulationsConclusions• Increases water production reliability during extreme storm events for Norfolk citizens and customers• Reduces risk of flood damage and costly repair / replacement of infrastructure• Provides a cost effective solution to improve resilience to many potential storm events• Provides a framework for Department of Utility infrastructure moving forwardAcknowledgements:Dwayne Amos, Associate Vice President, Hazen and SawyerCherryl Barnett, P.E., Engineering Manager, Norfolk UtilitiesQuestions?

Water Infrastructure Resiliency Planning for the City of Norfolk

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Water Infrastructure Resiliency Planning for the City of Norfolk

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