Research Question • Background • Biscayne Bay Ecosystem • Urban Seawater Floodwater • Field Survey (October 2, 2015) • Risks to the Biscayne Bay Ecosystem Bibliography

1. Johns Hopkins Engineering
Risks to the Biscayne Bay Ecosystem
from Urban Seawater Flooding,
Southeastern Florida
Submitted in partial fulfillment of graduate course
EN.575.415 (81) Ecology
Gary D. Moore, November 30, 2015

2. Outline
• Research Question
• Background
• Biscayne Bay Ecosystem
• Urban Seawater Floodwater
• Field Survey (October 2, 2015)
• Risks to the Biscayne Bay Ecosystem
Bibliography

3. Outline
FIGURES
Figure 1 - Area of Concern
TABLES
Table 1 – Special Status Species of Biscayne Bay
Table 2 – Potential Pollutants in Urban Seawater
Runoff
Table 3 – Ecosystem Risks

4. Research Question

5. The Situation: The100 year old stormwater
drainage system for the City of Miami Beach is
routinely overwhelmed with seawater from
rising sea level, inundating urban areas. To
remove flooding, the seawater (contaminated
with urban pollutants) is pumped back into
Biscayne Bay.
5
Research Question: What are the potential risks to the
Biscayne Bay ecosystem from urban seawater
floodwater?

6. Background

7. Facts about the City of Miami Beach1:
• Barrier island located off the southeast coast of the
State of Florida mainland.
• Forms the eastern boundary of Biscayne Bay
Aquatic Preserve (Biscayne Bay), a State of Florida
protected area
• Population: 92,000 (2014)2
7
1Florida Department of Environmental Protection, ND. About the Biscayne Bay Aquatic Preserve. [website] Available
at: < http://dep.state.fl.us/coastal/sites/biscayne/info.htm > [Accessed: November 20, 2015]
2US Census Bureau, 2015. State and County Quickfacts. [website] Available at: <
http://quickfacts.census.gov/qfd/states/12/1245025.html > [Accessed: November 29, 2015]
City of
Miami Beach
Image source: Google Earth
Biscayne Bay
Image source: Google Earth
AtlanticOcean
Gulf of Mexico
Not to scale
Not to scale
Figure 1 – Area of Concern

8. Biscayne Bay Ecosystem

9. Facts about Biscayne Bay1:
• “…expectional biologic, asthetic, and scientific value...to
be preserved for future generations”.
• 67,000 acres of submerged lands
• “…supports diverse biological communities including
submerged aquatic, coastal wetland and intertidal
habitats.”
• “…seagrass habitat is especially present...”
• Coastal habitats include mangroves and salt marshes
9
1Florida Department of Environmental Protection, ND. About the Biscayne Bay Aquatic Preserve. [website] Available at: <
http://dep.state.fl.us/coastal/sites/biscayne/info.htm > [Accessed: November 20, 2015]
Biscayne Bay is a priceless natural resource. Its clear water,
abundant wildlife, and aesthetic beauty enriches the lives of
southeastern Florida residents and visitors.

10. Common Name Taxonomic Classification Special Status
Fish
common snook
smalltooth sawfish
mangrove rivulus
Centropomus undecimalis
Pista pectinatus
Rivulus marmoratus
R
R
SSC
Reptiles
Atlantic loggerhead turtle
Atlantic green turtle
Atlantic hawksbill turtle
gopher turtle
Caretta caretta caretta
Chelonia mydas mydas
Eretmochelys imbricata imbricata
Gopherus polyphemus
T
E
E
SSC
Birds
roseate spoonbill
piping plover
little blue heron
snowy egret
tricolored heron
Arctic peregrine falcon
bald eagle
wood stork
osprey
brown pelican
Ajaia ajaja
Charadrius melodus
Egretta caerulea
Egretta thula
Egretta tricolor
Falco peregrinus tundrius
Haliaeetus leucocephalus
Mycteria americana
Pandion haliaetus
Pelecanus occidentalis
SSC
T
SSC
SSC
SSC
E
E
T
SSC
SSC
Table 1. Special Status Species of Biscayne Bay1
R – Rare; SSC – Species of Special Concern; T – Threatened; E – Endangered
1Florida Department of Environmental Protection, ND. About the Biscayne Bay Aquatic Preserve. [website] Available at: < http://dep.state.fl.us/coastal/sites/biscayne/info.htm
> [Accessed: November 20, 2015] 10

11. Urban Seawater Floodwater

12. • The island City of Miami Beach lies just above sea level.
One major road intersection (Alton and 10th) is 1.27 feet above
sea level (Benchmark MDC D-150).1
• Because of this, sea water flooding occurs, impeding pedestrian
and motor vehicle traffic, and degrading utility and other
infrastructure by corrosive seawater contact.2
• Flooded urban surfaces transfer pollutants to the seawater
floodwater through physical and chemical processes.
• The expected chemical composition of urban contact seawater
(Table 2, next slide) was developed using existing knowledge
from traditional urban floodwater management, local urban
landuse patterns, and effects of seawater corrosivity.3,4
• To clear flooded areas, seawater floodwater is pumped back
into Biscayne Bay.
12
1 City of Miami Beach, 2015. Miami Beach Survey Benchmark Viewer [online] Available at: <
http://gis.miamibeachfl.gov/slsurveyviewer/ > [Accessed: Sept 30, 2015]
2 Zimmerman, R. & Faris, C., 2010. Infrastructure impacts and adaptation challenges. Annals of the New York Academy of Sciences, vol.
1196, no. 1, pp. 63-86.
3 USEPA, 2003. Protecting Water Quality from Urban Runoff. [online] EPA 841-F-03-003. Available at: <
http://water.epa.gov/polwaste/npdes/stormwater/upload/nps_urban-facts_final.pdf > [Accessed: November 17, 2015]
4 NASA, ND. Corrosion Technology Laboratory: Corrosion in Concrete. [website] Available at: <
http://corrosion.ksc.nasa.gov/corrincon.htm > [Accessed: November 17, 2015]
Islands communities are especially vulnerable to
increases in sea level. Management of the resulting
flooding is a major challenge.

13. Pollutants Groups Comments
Oil, grease, vehicle chemicals1 Sources: Motor vehicles
Trash, sediment, and other particulates2 Sources: Urban society
Nutrients, herbicide, pesticides3 Sources: Lawn and urban garden chemicals
Bacteria and viruses4 Sources: Sanitary sewer backup, and pet waste
Metals (in solution)5,6 Sources: Road surfaces, metal utility infrastructure, motor vehicles;
Seawater can accelerate the corrosion process7
Seawater can invade unprotected concrete, corroding internal steel
reinforcements and causing expansion and cracking of concrete8
Combustion by-products; fuels; commercial trash and
chemicals
Sources: urban fires; leaking underground storage tanks; improperly
disposed commercial materials.
Table 2. Potential Pollutants in Urban Seawater Runoff
1 USEPA, 2003. Protecting Water Quality from Urban Runoff. [online], EPA 841-F-03-003. Available at: <
http://water.epa.gov/polwaste/npdes/stormwater/upload/nps_urban-facts_final.pdf > [Accessed: November 17, 2015]
2 Ibid
3 Ibid
4 Ibid
5 Zimmerman, R. & Faris, C., 2010. Infrastructure impacts and adaptation challenges. Annals of the New York Academy of Sciences, vol. 1196, no. 1, pp. 63-86.
6 USEPA, 2003. Protecting Water Quality from Urban Runoff. [online] EPA 841-F-03-003. Available at: <
http://water.epa.gov/polwaste/npdes/stormwater/upload/nps_urban-facts_final.pdf > [Accessed: November 17, 2015]
7 NASA, ND. Corrosion Technology Laboratory: Corrosion in Concrete. [website] Available at: < http://corrosion.ksc.nasa.gov/corrincon.htm > [Accessed: November 17,
2015]
8 Ibid
13

14. • Currently, the City of Miami Beach is modernizing the
historical (gravity-driven) storm water management system.
The new, active system pumps the seawater floodwater back
to the sea
• To protect Biscayne Bay, the new system1 uses a three step
process to physically remove some of the urban pollutants in
the floodwater effluent (steps are summarized below):
• Step 1 – Screening of large debris
• Step 2 – Settling of particulates (e.g., sand)
• Step 3 – Skimming of oil, grease, and floating debris
• A fourth step aerates the effluent to increase the dissolved
O2 concentration
• This Youtube video < https://youtu.be/wHdRn_PF6V8 >,
produced by the City of Miami Beach, describes the four
step process2
• However, the new active pump system does not remove
dissolved chemical constituents/pollutants.
14
1 City of Miami Beach, 2015. Engineering of Floodwater Management System [personal communication with
Margarita Wells, Office of City Manager]
2 Ibid

15. Field Survey (October 2, 2015)

16. • On October 2, 2015 Gary D. Moore conducted a field survey
of selected areas experiencing seawater flooding in the City
of Miami Beach near the Bay of Biscayne.
• The following five slides document the field survey with
photographs and notes.
16

17. Biscayne Bay
Image Source: Google Earth
Miami Beach
17
Area of Field
Survey
Photograph by G. Moore, October 2, 2015
Above: City of Miami
downtown (Mainland).
Picture taken from 10th
Street, Miami Beach.
Not to Scale
Biscayne Bay

18. 18
Photograph by G. Moore, October 2, 2015
Photograph by G. Moore, October 2, 2015
Above: View looking west along
drainage canal (foreground), and
Biscayne Bay (center). Left: High
water level in drainage canal,
threatening streets and surrounding
infrastructure.

19. 19
Photograph by G. Moore, October 2, 2015
Photograph by G. Moore, October 2, 2015
Above, and Left: Street and
sidewalks flooded with seawater due
to rising sea levels.

20. 20
Photograph by G. Moore, October 2, 2015
Photograph by G. Moore, October 2, 2015
Underground parking garage
flooded with seawater, entrance
at street level
Overwhelmed stormwater drain
discharging seawater into the street

21. 21
Photograph by G. Moore, October 2, 2015
Photograph by G. Moore, October 2, 2015
Above: Biscayne Bay seawater
floodwater discharge point
(submerged, picture bottom). Floating
booms (yellow) contain floating urban
trash in floodwater effluent.
Pumping floodwater back into canal
Photograph by G. Moore, October 2, 2015

22. Risks to the Biscayne Bay
Ecosystem

23. 23
Ecosystem Risks Mechanisms Drivers
Increase species mortality
Food chain disturbance
Species displacement
Eutrophication
Toxicity
Increase concentration of
phosphorus, nutrients from
lawn and garden chemicals;
increased concentration of
dissolved inorganic and
organic pollutants
Habitat modification
Increase aquatic plant
mortality
Species displacement
Decreased light aqueous
penetration
Increase concentration of
particulates in seawater
floodwater (direct), or
disturbance of bottom
sediments from pump outlet
(indirect)
Seawater floodwater effluent has the potential to
degrade the Biscayne Bay ecosystem. Table 3,
below, lists ecosystem risks, mechanisms, and
drivers.
Table 3 – Ecosystem Risks

24. Bibliography
Browder, J.A., et al., 2005. Biscayne Bay conceptual ecological model. Wetlands, vol. 25, no. 4, pp. 854-869.
Caccia, V.G. & Boyer, J.N., 2005. Spatial patterning of water quality in Biscayne Bay, Florida as a function of
land use and water management. Marine pollution bulletin, vol. 50, no. 11, pp. 1416-1429.
de Sylva, D.P., 1984. A bibliography and index of the Biscayne Bay ecosystem. Unpublished manuscript.
Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL
Finkl, C.W. & Krupa, S.L., 2003. Environmental impacts of coastal-plain activities on sandy beach systems:
hazards, perception and mitigation. Journal of Coastal Research, pp. 132-150.
Goodell, J., 2013.Goodbye, Miami. Rolling Stone, vol. 20.
Kirwan, M.L. & Megonigal, J.P., 2013. Tidal wetland stability in the face of human impacts and sea-level rise.
Nature, vol. 504, no. 7478, pp. 53-60.
Morris, J.T., et al., 2002. Responses of coastal wetlands to rising sea level. Ecology, vol. 83, no. 10, pp.
2869-2877.
Newton, A., et al., 2014. An overview of ecological status, vulnerability and future perspectives of European
large shallow, semi-enclosed coastal systems, lagoons and transitional waters. Estuarine, Coastal and Shelf
Science, vol. 140, pp. 95-122.
Odum, E.P., 1985. Trends expected in stressed ecosystems. Bioscience, vol. 35, no. 7, pp. 419-422.
Walther, G., et al., 2002. Ecological responses to recent climate change, Nature, vol. 416, no. 6879, pp. 389-395.
Weiss, J.L., et al., 2011. Implications of recent sea level rise science for low-elevation areas in coastal cities of the
conterminous USA. Climatic Change, vol. 105, no. 3-4, pp. 635-645.
Zhang, K., 2011. Analysis of non-linear inundation from sea-level rise using LIDAR data: a case study for South
Florida. Climatic Change, vol. 106, no. 4, pp. 537-565.