Climate Change and Coastal Hazards: Assessment for Long-Term Master - - PowerPoint PPT Presentation

Climate Change and Coastal Hazards: Assessment for Long-Term Master Water Plan

Tampa Bay Water UF Water Institute Symposium February, 2020

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Who Is Tampa Bay Water?

Tampa New Port Richey

• St. Petersburg

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Tampa Bay Water’s System

• Integrated supply system
• 13 wellfields
• 8 groundwater treatment

facilities

• Surface Water Treatment Plant
• Desalination Treatment Plant
• 9 pump stations
• 270 miles of transmission

mains

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• Population served: 2.5 million

Population served: 2.5 million

– Regional average annual demand 220 mgd to 259 mgd Regional average annual demand 220 mgd to 259 mgd

• Supply sources

Supply sources

– Groundwater Groundwater - permitted capacity 90 mgd ( permitted capacity 90 mgd ( capacity 120 mgd capacity 120 mgd ) – Surface Water Treatment Plant Surface Water Treatment Plant – permitted capacity 120 mgd permitted capacity 120 mgd

• Sustainable capacity 99 mgd; hydrology

Sustainable capacity 99 mgd; hydrology -dependent dependent

– Seawater Desalination Treatment Plant Seawater Desalination Treatment Plant – permitted capacity 25mgd permitted capacity 25mgd

• Sustainable capacity 16 mgd; drought resistant

Sustainable capacity 16 mgd; drought resistant

• Off

Off-stream regional reservoir stream regional reservoir – 15.5 billion gallons capacity 15.5 billion gallons capacity

Regional Supply Sources

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Regional Demand Projections

Phase 1 – 10 MGD Phase 2 - 10 MGD

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Three Water Supply Projects

2018 Long-term Master Water Plan Projects Approved for Further Studies

Surface Water Treatment Plant Expansion with existing source water Desalination Facility Expansion with existing source water New Groundwater Water Treatment Plant with South-Hillsborough Aquifer Recharge Project credits

South County Projects

New Groundwater Treatment via Aquifer Recharge Credits via SHARP Pipeline from Regional SWTP to South Hillsborough County

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Addressing Climate Change and Coastal Hazards

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Water Utility Climate Alliance

Vision: Climate Vision: Climate -resilient water utilities, thriving communities resilient water utilities, thriving communities Mission: Collaboratively advance water utility climate change Mission: Collaboratively advance water utility climate change adaptation adaptation

http://www.wucaonline.org http://www.wucaonline.org

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Florida Water & Climate Alliance (Florida WCA)

A stakeholder/scientist network advancing the relevance and usability of climate information, data and tools at local scales to help improve decision-making at an operational level.

http://www.floridawca.org

Collaborative Actionable Locally Relevant

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• Surface temperatures projected to increase 4-8° F by 2100

– Tampa Bay expected to see 2’-8.5’ sea level rise by 2100

• Vulnerability to heat waves and days with max temp exceeding 95°

projected to increase

• Health effects on vulnerable population projected to worsen
• Disruption in essential services projected to increase
• Urban areas experiencing shorter, intense wet seasons relative to rural areas

– Wet season length decreased by ~3.5 hours in the last 40-60 years

Climate Change Effects on Florida

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• Vulnerability Assessment:

– Flooding and storm surge from hurricanes – Sea level rise – Short and long- term water quality impacts

• Assessment performed on potential future projects

– Some project concepts evaluated have not moved forward

Long-term Master Water Plan – Vulnerability Assessment

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• SLOSH (Sea, Lake, and Overland Surge from Hurricanes) NOAA

model used

• Model results indicate:

– Surge increased as the speed of advance increased for storms moving E and NE – Surge levels related to tide stage – Surge increased as the hurricane category increased – Worst-case hurricane approach moving ENE

Storm Surge Analysis

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Storm Surge Analysis

Category 4 Category 5

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FACILITY FACILITY

Approximate Low Approximate Low Ground Elevation Ground Elevation (NAVD88) (NAVD88) Surge Elevation Surge Elevation Category 4 Category 4 Hurricane Hurricane (Feet, NAVD88) (Feet, NAVD88) Surge Elevation Surge Elevation Category 5 Category 5 Hurricane Hurricane (Feet, NAVD88) (Feet, NAVD88) Regional Surface Water Treatment Plant Regional Surface Water Treatment Plant 34 Adjacent to 25.2 Adjacent to 29.6 Seawater Desalination Plant Seawater Desalination Plant 9.5 22.7 27.1 New Gulf Coast Desalination Facility New Gulf Coast Desalination Facility 1 9 21.6 25.6 New South Hillsborough Wellfield and Groundwater WTP New South Hillsborough Wellfield and Groundwater WTP

1

100 NA NA New Tampa Augmentation Project Wellfield New Tampa Augmentation Project Wellfield

1

43 NA NA New Advanced WTP (at Regional Facilities Site) New Advanced WTP (at Regional Facilities Site)

1

34 Adjacent to 25.2 Adjacent to 29.6 New Treated Reclaimed Water Recharge & Recovery Wellfield and WTP New Treated Reclaimed Water Recharge & Recovery Wellfield and WTP1 100 NA NA Hillsborough Co. SHARP Recharge Wellfield Hillsborough Co. SHARP Recharge Wellfield 2 6 22.8 to 23.5 27.2 to 28.4 Hillsborough County South County AWTP Hillsborough County South County AWTP 2 38 NA NA City of Tampa H. F. City of Tampa H. F. Curren Curren AWTP AWTP

2

9 23.5 27.8

Facilities Affected by Storm Surge

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• 2ft – 8.5ft of SLR by 2100
• High uncertainty in future

projections

Sea Level Rise in Tampa Bay

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Facilities Affected by Sea Level Rise

FACILITY FACILITY

Approximate Low Ground Approximate Low Ground Elevation Elevation (NAVD88) (NAVD88) Surge Elevation Surge Elevation Plus Intermediate Low SLR Plus Intermediate Low SLR Projection Projection (Feet, NAVD88) (Feet, NAVD88) Surge Elevation Surge Elevation Plus Intermediate High SLR Plus Intermediate High SLR Projection Projection (Feet, NAVD88) (Feet, NAVD88) Seawater Desalination Plant Seawater Desalination Plant 9.5 23.8 24.8 New Gulf Coast Desalination Facility New Gulf Coast Desalination Facility 1 9 22.7 23.8 New Tampa Augmentation Project Wellfield New Tampa Augmentation Project Wellfield

1

22 25.2 26.2 Hillsborough Co. SHARP Recharge WF Hillsborough Co. SHARP Recharge WF

1

6 23.9 to 24.6 25.0 to 26.8 Hillsborough County South County AWTP Hillsborough County South County AWTP 2 38 23.1 24.1 City of Tampa H. F. Curren AWTP City of Tampa H. F. Curren AWTP

2

9 24.6 25.6

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• Hazards considered for overall analysis:

– Flooding 25%

• 5=within inundation area; 3=marginal/adjacent; 1= outside of flood area

– Storm Surge 35%

• 5=within surge area; 3=marginal/adjacent; 1= outside surge area

– Sea Level Rise 15%

• 5=within surge area Cat 4+1.7ft; 3=marginal/adjacent +1.7ft; 1=outside flood area

– Changes in Water Quality and Availability 25%

• 5=significant changes in quality/availability; 3=minor changes in quality/availability; 1=impact unlikely

Overall Vulnerability Assessment

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Results of Vulnerability Assessment

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• All plans must consider multiple

futures

• Robust plans for multi -scenario

future better than an optimal plan for a single-scenario future.

• Plans must be flexible and

adaptive

• Each scenario offers options for

adaptation

Climate Change Plan

Credit: DMDU Society; deepuncertainty.org

Decision Points Present Future Near-term strategy

C A D B

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• Engaging the public is crucial and

challenging

– Human lifespans vs. climate timescale – Psychological barriers (i.e. “the

• strich effect”)

– Uncertainty often equated to complete lack of knowledge (i.e. “throwing the baby with the bathwater effect”) – How are we going to pay for it?

Communication and Public Engagement

Credit: Water Utility Climate Alliance

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Ivana Kajtezovic, Planning Program Manager, Tampa Bay Water Tirusew Asefa, Ph.D., P.E., Planning & Decision Support Manager, Tampa Bay Water Ken Herd, Chief Technical Officer, Tampa Bay Water Andre Dieffenthaller, Vice President, Hazen & Sawyer Stephanie Ishii, Principal Scientist, Hazen & Sawyer

Authors’ Credit

Questions