DECREASING THE THREAT OF STORM-RELATED FLOODING TO HUMAN LIFE IN SUFFOLK COUNTY,

LONG ISLAND

Storm surge is an abnormal rise in water level, over and above the regular astronomical

tide

Storm surge intensity depends on many factors including the shape of the coast, the

storm track, storm intensity, storm speed, storm size, and the slope of the sea floor.

Due to climate change, 100-year flood events can occur as often as every 3 years by the

year 2100 (Shepherd et al, Assessing Future Risk 2012).

The low elevation of the southern shores of Long Island, NY leaves it quite susceptible to

flooding.

"Risk" is the likelihood of bodily harm occurring to the people exposed to flooding, based

on factors including infrastructure condition, inundation extent, population density,

education level, and poverty rate (Shepherd et al, Assessing Future Risk 2012).

Our project focused on the 86 miles of Suffolk County, Long Island

INTRODUCTION: THE RISK

The amount of people at risk to the dangers of storm-surge-related flooding is predicted

to increase by as much as 47% along the shores of southern Long Island, NY by 2080

(see fig. 1 and 2, Shepherd et al., Assessing Future Risk 2012) .

SO WHAT’S THE PROBLEM?

To reduce the increased amount of people exposed to storm surge through sea level rise

in Suffolk County from 130,718 exposed individuals to 109,802 exposed individuals by

2080 (see table 1) .

OUR GOAL

Caitlin Corona, Zachary Frenkel, Ilanna Schuster, and Katarzyna Zajac; Macaulay Honors College at Queens College

SOURCES

STRATEGY B: UTILIZE AN EVACUATION PLAN

There is already an existing evacuation plan for Suffolk County, Long Island, NY, which

can be viewed on official Suffolk County Government website, and includes:

• Guides for creating emergency supply kits

• Map of existing evacuation routes in Suffolk County

• Map of existing emergency shelters in Suffolk County

• Link to sign up for Code Red Emergency Notifications

Purpose of plan is to get people out of zones at-risk for storm-surge-related flooding into

existing public shelters further inland before the arrival of dangerous hurricanes and

tropical storms

HOW TO IMPLEMENT STRATEGY B

Evacuation plan is already in place in Suffolk County, Long Island, NY and can

be utilized during the next category 3 or lower hurricane (out of predicted four)

Based on success of evacuation, i.e., how many people evacuate when

required, a projection can be made about success of future evacuations and

about whether or not current plan is enough to achieve overall goal

YES: If it is, can continue to be used during each of the successive storm-

surge-related flooding events predicted to occur by 2080

NO: If it is not, research must be done on how to expand and improve the

current plan (if that is even possible before the next predicted storm), and if

possible, to implement the improved strategy during all consecutive hurricanes

predicted to occur by 2080

THE COST: IS IT WORTH IT?Value of one human life: $6.9 million (U.S. News-Environment: How to Value Life,

msn.com)

Number of deaths per category 3 hurricane: 35 (Hurricane Fran) to 700 (1938

hurricane)

Cost of the four hurricanes predicted between now and 2080: $966,000,000 to

$19,320,000,000

Cost of implementation of Strategy A: between $10 billion and $17 billion (Queens

Courier: Preventing Another Sandy)

Cost of implementation of Strategy B: $344 million by 2080, with cost per evacuation

$86 million (Wolshon et al., Review of Policies and Practices for Hurricane Evacuation

2005)

Fig. 1 Overall risk from category 3 storm surge in Southern Suffolk County, NY (top: present; bottom: with .5 m sea level rise) The .5 m SLR is based on the projection of the A2 emissions scenario for the year 2080

Fig. 2 Changes in storm surge risk with a .5-m rise in sea level. (Shepherd et al, Assessing Future Risk 2012)

Table 1 Estimates of affected areas, numbers of people affected, and property loss due to storm surge (Shepherd et al, Assessing Future Risk 2012)

STRATEGY A: PROTECT COASTLINE WITH A SEA WALL

There are currently no effective barriers protecting the southern shores of Long Island,

NY from the storm-surge-related flooding of category 3 or lower hurricanes

The successful construction of a 20-foot retractable sea wall along the 86 miles of

Suffolk County’s coastline by 2080 could effectively protect the people living in this

area from the harmful effects of such flooding events

HOW TO IMPLEMENT STRATEGY A

WILL THESE IDEAS WORK?STRATEGY A: Protect Coastline with a Sea Wall

Will protect 100% of Suffolk County’s population

Will be more appealing to residents because:

• Property as well as people will be protected from flooding

• Will not affect aesthetics of coastline—wall is retractable (see fig.

3)

Is very expensive. It will be very difficult, if not impossible, to receive funding for an

expensive project that protects a very small area of Long Island (http://phys.org)

STRATEGY B: Utilize an Evacuation Plan

Is cheaper than a sea wall

Is less costly than predicted loss of human life due to storm-surge-related flooding

Will not necessarily decrease risk by half the predicted amount, because many

residents may choose to remain in evacuation zone despite the implementation of

the Evacuation Plan

• Because of experiences of harm due to flooding caused by the

recent Hurricane Sandy, many residents may be easily convinced

to evacuate

• However, if less than 50% of exposed people do evacuate, then

we have not reached our goalTHE BOTTOM LINE

Without cost being a factor, Strategy A is the preferred option

We recommend that an implementation of Strategy A be attempted

There should be an effort made to gain approval for a sea wall and raise the

necessary funds, so that construction can start by 2040

At the same time as construction is taking place, the current evacuation plan for

Suffolk County should continue to be utilized on the south shores of Long Island,

NY

If there is no way to guarantee the start of construction by 2040, Strategy A

should be rejected and Strategy B should be implemented instead

Fig. 3 Diagram of sea wall already in place in the Thames River in London, England. The retractable design allows for flood protection without interfering with industries or aesthetics of the coastline.

Shepard, Christine C., Agostini, Vera N., Gilmer, Ben., Allen, Tashya., Stone, Jeff., Brooks,

William., Beck, Michael W. (2012). Assessing future risk: quantifying the effects of sea

level rise on storm surge risk for the southern shores of Long Island, New York. Natural

Hazards, 60, 727–745.

Wolshon, B., Urbina, E., Wilmot, C., and Levitan, M. (2005). Review of Policies and

Practices for Hurricane Evacuation. I: Transportation Planning, Preparedness, and

Response. Natural Hazards Review, 6(3), 129-142.

Research is necessary to determine whether or not it is possible to construct any type of

sea barrier along the southern shores of Long Island without interfering with any natural

coastal ecosystems

• This research must be completed within the next 10 years

If it is possible that the retractable sea wall will not interfere with these ecosystems, a

blueprint for the wall should be drafted by the Army Corps of Engineers of New York by

2030

A group of lobbyists interested in reducing human exposure to storm-surge-related flooding

should be enlisted to rally the support of local and federal politicians for this design by the

year 2035

Approval from the local and federal government, in the form of legislation, permits, and at

least partial funding, should be gained for the construction of a sea wall by 2040

Construction should start immediately after approval is gained (within one year)

At least half the length of the retractable sea wall should be completed by the year 2060

The full sea wall should be completed no later than the year 2080