Sea Level Rise Information New Smyrna Beach Coastal Community Resiliency Program Environment and Cultural Resources Session February 20, 2018 Frank Marshall, PhD PE Frank Marshall Engineering, PL Cetacean Logic Foundation, Inc New Smyrna Beach, FL

What is Sea Level Rise (SLR)? SLR is an increasing trend in the average elevation of the surface of the global oceans over the past 50 years The two main mechanisms: thermal expansion of ocean water due to higher temperatures (no additional water mass) melting of major stores of land ice like glaciers and ice sheets (additional water mass, particularly Arctic and Antarctica ice) The melting rate and volume of Antarctica ice continues to increase (big time in 2017) SLR is one of several lines of evidence supporting the hypothesis that the global climate has recently warmed

Observed Data: Increase in South Florida Atlantic Ocean Level Increase = 0.61 ft since 1965 = 0.013 ft/yr = 0.15 in/yr KW = -0.31 + (0.00002529*date) Pr > |t| (both terms) = <.0001

Local Florida SLR Projections: Southeast Florida Regional Climate Change Compact (2015) 1992 = 0

For Other Basic Climate Indicators: What is Expected in the Florida Region by 2050? from SFWMD (2011) and Regional Climate Change Compact (2015) Temperature – increase of 1 – 2 degrees C Rainfall: +/- 5% (-3 to +2 inches) more heavy precipitation increase in frequency and duration of dry spells Evaporation / transpiration: +3 to +6 inches high uncertainty in evaporation changes Tropical Storms – fewer but more powerful storms Increased salinity in coastal water bodies

Case Study – 2017 Turnbull Creek Bridge Coastal Hydrology Study

Existing Data Were Available for Use USGS 8721136, adjacent to bridge, 10-12-1978 to 5-4-1979 Mean tide range = 1.15 ft USGS 02248060, adjacent to bridge, 10-1-2000 to 9-30- 2009 Daily average water elev. = -0.388 ft NAVD88 Hurricanes Frances and Jeanne (2004) are in this data FDEP – near USGS 8721136, 1983 – 2001 Mean High Water (MHW) = 0.29 ft NAVD88, diurnal range = 0.31 ft Unusual to have this much information close to project - major cost savings

Most Useful Available Data USGS 02248060 monitoring station – adjacent to existing bridge Hurricane Francis Hurricane Jeanne

Conclusions Sea level is increasing and forecast to continue doing so according to observed data Increased temperature, higher evap., fewer but more powerful tropical storms, rainfall = +/- ?? For Florida – best SLR projections for planning purposes: Southeast Florida Regional Climate Change Compact (2015) Design of Turnbull Creek Bridge (currently under construction) was subject to recent revisions to bridge design guidelines to accommodate: SLR Hurricane storm surge and waves from wind