1. How Everglades Restoration Can Mitigate Some Effects of Sea Level Rise in South Florida
By the Arthur R Marshall 2013 Interns: Sarah Denisen, Casey Hickcox, Jessica James, Tomena Scholze, and Kelsie Timpe

2. Climate Change and Sea Level Rise
May 9, 2013: Mauna Loa above 400 ppm
Pre 1870s: ppm
Greenhouse gas (GHG) emissions have grown since before the 1870s.
Over the last 150 years, carbon dioxide concentrations have increased from 280 parts per million (ppm) to more than 395 ppm
2012: Highest value measured for over the previous 800,000 years!
Today’s rate of increase is more than 100 times faster than the increase that occurred the end of the last ice age.
Fig 1: NOAA, Climate.gov

3. Climate Change and Sea Level Rise
The net effect of human activities has been one of warming with radiative forcing of +1.6 W/m^2. (IPCC 2007)
The increase in GHGs has altered the outgoing solar energy from the Earth-Atmosphere system, causing average global temperatures to increase.
Fig 2: IPCC 2007

4. Warming surface temperatures has caused sea level rise via thermal expansion of the oceans, and glacial and ice sheet melting in the poles.
Fig 3: NOAA 2012

5. Climate Change and Sea Level Rise
IPCC 2007 Report predicts a sea level rise rate of 1.9 mm/yr. However, the report doesn’t take into account the contribution from melting continental ice sheets in Greenland and Antarctica.
Predictions taking into account the melting of ice sheets range from a rate of 3 to 3.5 mm/yr of sea level rise (Rahmstorf 2007).
The US National Climate Assessment predicts with high confidence that the sea will rise at least 0.2 m (8 inches) and no more than 2 m (6.6 ft) by 2100 (NOAA 2012).
Table 1: NOAA 2012
The US National Climate Assessment predicts with high confidence that the sea will rise at least 0.2 m (8 inches) and no more than 2 m (6.6 ft) by 2100 (NOAA 2012).

6. Sea Level Rise: The Future of Florida

7. History of Everglades Restoration
1920s and 1940s: Destructive hurricanes caused massive flooding damage
1948: Central & Southern Florida Project (C&SF) was put into place
Project managed water flow by putting in system of canals and levees
Damaged overall Everglades system
2000: Central Everglades Restoration Plan (CERP) approved in Water Resources Development Act (WRDA)
Historic Flow
Current Flow
CERP Future Plan Flow

8. Outline of Sea Level Rise Threats
Threats to the urban environment
Saltwater Intrusion
Increased flooding
Infrastructure damage
Threats to the natural environment
Storm Surge
Saltwater Inundation
Mangrove Destruction
Habitat Conversion
Trophic Disruption

9. Threats to the Natural Environment: Storm Surge
Physical Erosion
Sediment removal
Mangrove destruction and removal
Soil subsidence
Chemical Erosion
Saltwater inundation
Wetland Destruction
Almost 3100 acres in S.Fla due to Hurricane Wilma
Almost 50k acres lost in Louisiana due to Hurricane Katrina
(1 acre = almost 1 football field)
Storm surges from ft were common during Hurricane Katrina

10. Healthy Ecosystems Provide Natural Protection
Mangroves - 'Natural wall'
Create peat dam
Increases drag on water motion
Absorbs wave energy
Decreases fetch in wave action
Inland plants
Prevent creation of waves
Holds sediment in place
inland “riparian” forests offer no significant storm surge protection
storm surge reduced by 4.7 cm km^-1 by marshes during Andrew - C1
Wind speed shown to increase damages while marshes shown to decrease - C1

11. Mangrove Wave Attenuation During Storm Surge:

12. Threats to the Natural Environment: Saltwater Inundation
Peat decomposition
Oxidative destruction
Nutrient Enrichment
Phosphorus
Salinity increase
24% of total global C in peat
Seawater Okeechobee Everglades Goal

13. Threats to the Natural Environment: Mangrove Destruction
Mangrove Threats
Soil Erosion
Too fine sediment
Hypersalinity
Migration Capacity Limited
SLR <9 cm/yr - Acceptable
SLR 9-12 cm/yr - Stressed
SLR >12 cm/yr - Threatened
As sea level rises, mangrove seedlings will propagate inland, thus moving the forest away from shore
Migration will only occur if sea rises slow enough
Mangrove forests will not be able to migrate if sea rises faster than 12 cm per decade

14. Mangrove Migration

15. Threats to the Natural Environment: Habitat Conversion
Salinity increases and reduced freshwater
-> vegetation community shifts
aquatic vegetation regime shifts
tidal marsh shifts and submergence
buttonwood/coastal hammock loss
Differing rates of migration
-> elimination of some habitats
1. clear water, SAV to turbid water, phytoplankton dominance 2. risk of conversion to salt marsh, loss of marsh by submergence, accelerated decomp by saltwater intrusion/innundation 3. shift from glycophytes (buttonwoods) to halophytes(mangroves); complete collapse with loss of intermediate-salinity niche
increased rates of migration due to rapidly changing environmental conditions, including stress related to saltwater inundation and drought; coastal, saline-tolerant systems such as mangroves, salt marshes, and intertidal mudflats may migrate inland faster than intermediate- and low- salinity systems such as buttonwoods, hardwood hammocks, and freshwater marshes

16. Salinity-induced vegetation shifts reduce ecosystem values
example: tidal marshes - freshwater marshes have significantly higher productivity (biomass), nitrogen accumulation rates, biodiversity, and nitrification rates than saltwater marshes (Craft et al. 2009)
example: freshwater marsh ($16,500/ac) -> saltwater marsh ($7,400/ac) -> intertidal mudflat ($5,200/ac) -> coastal Gulf of Mexico ($4600/ac)
our study: see methods
Total Ecosystem Valuation
(TEV)

17. Total Ecosystem Value (TEV) Decreases as Habitats Shift
TEV is $74 billion with no SLR effects in study area
TEV decreases to $5 billion with 5 ft. of SLR
Losses occur as ecosystems degrade to less valuable habitats through salinity changes
C sequestration values decreased from $32 million to $490 k due to mangrove loss

18. Threats to the Natural Environment: Trophic Disruption
Biological effects of physical changes caused by SLR and flow alterations
disrupted trophic interactions
productivity effects
population/community structure changes
Examples:
coastal fish nurseries
wading bird nesting/feeding
periphyton composition

19. The Urban Side
2010 population along the lower east coast was approx. 5.6 million
2010 gross water demand of 1,775,000,000 gallons per day
2030 population projected to increase by 18% to approx. 6.6 million
2030 gross water demand for all uses is projected to increase by 213 million gallons per day (12%)

20. Climate Change Threatens Water Supply
Warming will change in the rate of evapotranspiration
Unpredictable weather patterns and rising temperatures may increase water demands
Less frequent but more intense rainfall, with longer dry periods in between, may increase total annual rainfall but decrease total useable rainfall - more water may be lost to tide or runoff.
This scenario increases the necessity for long term water storage for use during dry periods.

21. Salt Water Intrusion Threatens Water Supply
The majority of public water supply is pumped from shallow wells
Salt water contaminates shallow well fields, making them unusable
Many coastal well fields are already experiencing salt water intrusion and must be abandoned
Utilities at risk - Lake Worth, Lantana, Hillsboro Beach, Dania Beach, Hallendale Beach, Miami-Dade south wellfields, Florida City, Homestead, and the Florida Keys Aqueduct Authority.

22. The Aquifer Systems under South Florida
Surficial Aquifer System (SAS)
Floridan Aquifer System (FAS)
SAS holds freshwater from surface level to about 200 ft in depth
FAS holds brackish water in several layers
Photo Credit: SFWMD

23. How Saltwater Intrusion Works
When water is withdrawn faster than it is recharged, seawater moves in
With SLR, pressure from the a growing ocean will push more saltwater inland.
Photo Credit: USGS

24. Connection between Water Supply and the Greater Everglades
Water from Lake Okeechobee, the Water Catchment Areas (WCAs) and the C&SF Canals recharge the SAS and Biscayne Aquifer
Photo Credit: SFWMD
Photo Credit: SFWMD

25. How can we meet future water supply demand?
Diversify our water sources
Increase surface water storage
Use reclaimed water and rain for non-potable uses
Increase water conservation
Restore the Everglades
Photo Credit Ken Kaye

26. Alternative Water Supply Options
Temporary fix - move Biscayne and surficial aquifer system (SAS) wells inland.
Desalinize brackish water from the Floridan Aquifer System (FAS).
Desalinize saltwater from the ocean.

27. SAS and the Biscayne Aquifer
Salt water intrusion necessitates abandoning wells or moving them further inland.
Moving wells is costly - Earl King, assistant director of utilities for the City of Hallendale Beach, estimates moving a small wellfield inland will cost $8,500,000.
Only a temporary fix.
Relying exclusively on the SAS and the Biscayne is not a viable option to meet future water demand.
Other water sources must be explored.

28. Floridan Aquifer System - FAS
FAS is brackish – requires treatment (RO)
Construction is costly.
RO highly energy intensive.
Deep injection wells (DIWs) are necessary

29. Seawater Desalinization
Unlimited, drought-proof source of water
RO is highly energy intensive and expensive
Brine byproduct of RO can be damaging to marine ecosystems.
Advances technology reducing cost
Co-location of desal facilities and coastal power plants

30. SAS

31. Supplemental Sources and Conservation Measures
Rainwater harvesting, use of reclaimed water and water conservation practices will help reduce water supply demands
Photo Credit: EPA

32. Reclaimed Water Used for irrigation, agricultural and industrial uses
Reduces pumping from groundwater
Reduces quantity of wastewater disposed of via ocean outfalls and deep injection wells
Reduces need for fertilizer
Wastewater flows predicted to increase from 636 MGD in 2010 to 832 MDG by 2030
Is no more dirty than ocean water!
Photo Credit: SunSentinel

33. Rainwater Harvesting Inexpensive Reduces stress on water supplies
Reduces stormwater runoff, pollution and flooding
Photo Credit: EcoFriend
Photo Credit: SunSentinal

34. Everglades Restoration Will:
Recharge the aquifers – extend the life of wellfields
Increase surface water storage – reduce amount of water lost to tide
Strengthen freshwater head – push back the salt water intrusion line
Secure resource and water supply – ensure a bright future for the next generation.
Photo Credit: Rodney Cammauf, USNPS

35. The Solution: Everglades Restoration
More water in the Everglades ecosystem will:
Help recharge the shallow Biscayne Aquifer
Provide more surface water storage
Prevent peat degradation
Push back saltwater intrusion
Reduce nutrient enrichment
Maintain freshwater habitats for plants and wildlife.
Maintain the coastal mangrove storm barriers

36. THANK YOU! Questions?