Adaptation in a Sea of Uncertainty Sea-Level Rise Planning at the - PowerPoint PPT Presentation

Adaptation in a Sea of Uncertainty Sea-Level Rise Planning at the Local Level Jason M. Evans, Ph.D. Assistant Professor of Environmental Science Stetson University November 16, 2016 Florida Water and Climate Alliance Arcadia, FL Stormwater outfalls, Satellite Beach, FL July 19, 2016 Photo by Emily Niederman

My Past Few Years Satellite Beach, FL Public Works 2

Assertion #1 Climate change adaptation is one of the most complex and daunting challenges ever faced by human civilization. 3

Sea Level Rise is a big deal for FL… 4

News release on July 28, 2014 5

Miami Beach http://s13.thereal deal.com/trd/m/up/2013/07/Miami-flooding-4-13-13.jpg.jpg 6

Tidal flooding on Tybee Island, GA US Highway 80 October 27, 2015 http://sav-cdn.com/sites/default/files/imagecache/superphoto/14845662.j pg Third highest tide on record (since 1935) for this gauge Only exceeded by tropical storm surges 7

Nuisance Floods Per Year at Key West 35 *Nuisance flooding threshold for Monroe County, as defined by Sweet et al. (2014) 30 Sw eet, W., J. Park, J. Marra, C. Zervas, and C. Gill. 2014. Sea Level Rise and Nuisance Flood Frequency Changes around the United States. NOAA Technical Report NOS CO-OPS 073. 25 20 15 10 5 0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 8

Nuisance Floods Per Year at Vaca Key (Marathon, FL) 35 *Nuisance flooding threshold for Monroe County is 1.08 ft above MHHW, as defined by Sweet et al. (2014) 30 Sw eet, W., J. Park, J. Marra, C. Zervas, and C. Gill. 2014. Sea Level Rise and Nuisance Flood Frequency Changes around the United States. NOAA Technical Report NOS CO-OPS 073. 25 20 15 10 5 0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 9

Nuisance Floods by Year at Tybee Island, GA (Ft. Pulaski Tide Gauge) 25 20 NOAA nuisance flood threshold for Fort Pulaski: 9.2 feet above MLLW 15 10 5 0 10 Data Source: https://tidesandcurrents.noaa.gov/stationhome.htm l ?id=8670870

Assertion #2 Very few development decisions being made today in vulnerable coastal communities are considering the consequences in a worst- case scenario at 2100. 11

For example… 12

Population growth = Underestimation of problem 7,000,000 Scenario: ~2 meters of sea level rise at 2100 6,000,000 People displaced by sea level rise 5,000,000 Projected Populations 4,000,000 Current Populations 3,000,000 2,000,000 1,000,000 0 13

Credit: M.J. Hauer, J.M. Evans and D. Mishra 14

Assertion #2 Very few development decisions being made today in vulnerable coastal communities are considering the consequences in a worst- case scenario at 2100. This is understandable – even appropriate – given uncertainty about the future over such a long time-horizon. 15

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BIG difference between low and high scenario ~6.1 million people affected Statewide in FL ~1.2 million people affected 17

Garden Shed or Nuclear Power Plant? “ Risk-based” scenario planning for sea-level rise… http://www.homebase.co.uk/cmsresource/i mage/42 https://nuclear.gepower.com/content/dam/gepower- 316/landscape_rati o3x2/440/300/563f6a641d71348 nuclear/global/en_US/images/her o-images/Nine-Mile- 42bc93d991c4fa65a/zj/how-to-erect-a-shed--- Point-Nuclear-Plant-cropped.jpg header-image.jpg 18

Assertion #3 Almost all coastal communities, even those not yet seeing dramatic direct saltwater flooding from king tides, are being impacted by various stormwater drainage failures. 19

General Timeline of Sea Level Rise Impacts on the Built Environment Potential for saltwater Ground floor corrosion and flooding of intrusion of Stormwater houses and drainage underground commercial pipes issues buildings Saltwater Flooding of Flooding of flooding of ancillary high value yards and structures critical roads (pavilions, infrastructure sheds, etc.) such as wastewater facilities and electrical substations 20

XXX Figure by Emily Niederman 21

SW Tybee Island, GA: November 14, 2012 22

SW Tybee Island, GA: Local Government Action Action: Stormwater backflow preventers and pipe enlargement ~$3 Million Investment 23

St. Marys, GA: Mean Higher High Water, Today 24

St. Marys, GA: Mean Higher High Water, 1 Foot SLR 25

St. Marys, GA: Mean Higher High Water, 2 Foot SLR 26

St. Marys, GA: Mean Higher High Water, 2 Foot SLR 27

Osborne Waterfront Stormwater Drainage St. Marys, GA 28

Osborne Ave., St. Marys, GA (Facing North) 29

Osborne Ave., St. Marys, GA (Facing South) 30

What Happens When it Rains???? 31

Idealized Tidal Scenarios (24-Hour Rainfall Event) Sine Tide Cosine Tide 4 Elevation (Feet Above NAVD88) 4 Elevation (Feet Above NAVD88) 3 3 2 2 1 1 0 0 0 4 8 12 16 20 24 -1 0 4 8 12 16 20 24 -1 -2 -2 -3 -3 -4 -4 -5 -5 Time (Hours) Time (Hours) Negative Cosine Tide Negative Sine Tide 4 4 Elevation (Feet Above NAVD88) Elevation (Feet Above NAVD88) 3 3 2 2 1 1 0 0 0 4 8 12 16 20 24 -1 0 4 8 12 16 20 24 -1 -2 -2 -3 -3 -4 -4 -5 -5 Time (Hours) Time (Hours) 32

Osborne Waterfront Stormwater Drainage St. Marys, GA 25-Year Rainfall with Peak Flow at High Tide (Cosine Scenario) 33

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Assertion #4 People start to really take notice when roads start flooding on a sunny day. 35

General Timeline of Sea Level Rise Impacts on the Built Environment Potential for saltwater Ground floor corrosion and flooding of intrusion of Stormwater houses and drainage underground commercial pipes issues buildings Saltwater Flooding of Flooding of flooding of ancillary high value yards and structures critical roads (pavilions, infrastructure sheds, etc.) such as wastewater facilities and electrical substations 36

Tidal flooding on Tybee Island, GA US Highway 80 October 27, 2015 http://sav-cdn.com/sites/default/files/imagecache/superphoto/14845662.j pg Third highest tide on record (since 1935) for this gauge Only exceeded by tropical storm surges 37

“Nuisance” flooding in Big Pine Key September 29, 2015 Photo credit: Greg Corning, provided by Monroe County staff 38

* http://sls.geoplan.ufl.edu/documents-links/ *General planning assessment tool requires additional data for use in site-level decisions 39

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“Nuisance” flooding in Big Pine Key September 29, 2015 Photo credit: Greg Corning, provided by Monroe County staff 42

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Modeling: More Accurate by the Day Policy Framing: Much More Difficult What is an appropriate level of service for maintaining Tides Higher than 1.08 MHHW* at Vaca Key Tide Gauge stormwater and roads under sea level rise? 35 Cost of upgrades and maintenance for elevation of road bed, improved drainage, pumps, etc.? 30 How much are citizens willing to pay for enhanced 25 stormwater and road service? 20 What thresholds may make a public road no longer viable from an economic and/or engineering perspective? 15 When does retreat become the only option? 10 5 0 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 44

Thanks and acknowledgments Monroe County BOCC and staff Tybee Island, GA City Council and staff St. Marys City Council and staff University of Florida GeoPlan: Crystal Goodison FL Sea Grant: Thomas Ruppert, J.D. Stetson University undergraduates: Emily Niederman, Justin Baumann, Zella Conyers, Alex Clark, Enric Cordoba, George Winsten 45