The City That Plans to be Flooded
A guest post by Douglas Hill, a consulting engineer and an adjunct lecturer at the School of Marine and Atmospheric Sciences at Stony Brook University in New York.
Hurricane Irene, remember? Irene, diminished to a mere tropical storm when it struck New York City, came and went, soon disappearing from the news. But think back to August 26 when Irene, a Category 3 hurricane with winds of more than 110 miles per hour, was approaching the North Carolina coast and headed directly for New York City. Mayor Michael R. Bloomberg called a news conference to order 370,000 people to evacuate their homes. Then he stepped aside, and MTA chairman Jay Walder stepped to the microphone and announced that public transportation--buses as well as trains--was being shut down.
Figure 1. GOES-East visible satellite image of Irene taken at 7:45 am EDT on Sunday, August 28, 2011. At the time, Irene was a tropical storm with 65 mph winds, making landfall on Long Island, New York. Image credit: NOAA Environmental Visualization laboratory.
Evacuation without transportation: a novel concept that the mayor described as "preparing for the worst and hoping for the best." Fortunately, hoping for the best worked.
Unfortunately, the City is still hoping for the best, and it is not preparing for the worst. The coastal storm plan of the Office of Emergency Management (OEM) includes strategies for storm tracking, public information, evacuation procedures, people with special needs, recovery, and restoration, but nothing to prevent flooding.
In other words, New York City is planning to be flooded--and according to the National Hurricane Center, it will be. Based on the historical record, hurricanes of Categories 1, 2 and 3 will strike the New York region on an average of every 17, 39 and 68 years, respectively. The City has been overdue for a Category 1 hurricane--Irene should have been no surprise--and we may expect hurricanes of Categories 2 and 3 within the next decade or two. In testimony to a U.S. Senate committee, Max Mayfield, the former director of the National Hurricane Center, said, "It is not a question of if a major hurricane will strike the New York area, but when" (his emphasis.)
The greatest potential for loss of life from a hurricane has historically been from the storm surge. If the eye of a Category 3 hurricane crossed the New Jersey shore, the surge could reach 24 feet--compared with 4.5 feet in Hurricane Irene's--flooding the World Trade Center site and Wall Street, with City Hall resting on a separate island south of the rest of Manhattan. The ripples from a crippled financial district in lower Manhattan would be felt worldwide. In a severe hurricane, the OEM has estimated that up to three million people would have to evacuate, if that can be imagined.
Figure 2. The height above ground that a mid-strength Category 2 hurricane with 100 mph winds would push a storm surge into New York City in a worst-case scenario. The image was generated using the primary computer model used by the National Hurricane Center (NHC) to forecast storm surge--the Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model. The accuracy of the SLOSH model is advertised as plus or minus 20%. This "Maximum Water Depth" image shows the water depth at each grid cell of the SLOSH domain. Thus, if you are inland at an elevation of ten feet above mean sea level, and the combined storm surge and tide (the "storm tide") is fifteen feet at your location, the water depth image will show five feet of inundation. This Maximum of the "Maximum Envelope of Waters" (MOM) image was generated for high tide and is a composite of the maximum storm surge found for dozens of individual runs of different Category 2 storms with different tracks. Thus, no single storm will be able to cause the level of flooding depicted in this SLOSH storm surge image. Consult wunderground's Storm Surge Inundation Maps page for more storm surge images of the U.S. coast.
Other major ports have taken measures to prevent being flooded. After the 1938 hurricane, storm surge barriers were built in New England to protect New Bedford, Providence and Stamford. After a disastrous storm in the North Sea in 1953, the Thames Barrier was built to protect London, and the Delta Plan was started in the Netherlands which includes three such barriers, one protecting Rotterdam, Europe's busiest port. Following Hurricane Katrina, a long-disputed barrier was constructed at the entrance to Lake Pontchartrain along with several others, which are now considered to make New Orleans hurricane-proof to Category 3 storms. Barriers are being completed to protect St. Petersburg, Russia, and Venice, Italy.
The heart of New York City could be protected in the same way. Moveable barriers, closed only when the city is threatened with major coastal flooding, could be placed at the upper end of the East River, across the Narrows and at the mouth of the Arthur Kill. Possibly, the latter two could be replaced with a single, longer barrier extending from Sandy Hook to the Rockaway peninsula. Modeling studies have demonstrated that the barriers would work. Four major engineering firms have presented conceptual designs and cost estimates for barriers at these locations. The estimated costs for these individual barriers range from $1 billion to $4.6 billion, with the total of the two or three needed less than $10 billion, comparable to other major infrastructure projects planned or underway.
Figure 3. Proposed hurricane storm surge barrier for New York City near the Verrazano Narrows Bridge. Image credit: Arcadis, Inc.
But unlike the original, the 2010 revision of plaNYC, the City's principal planning document, makes no reference to storm surge barriers. The City's latest plans are seen in the March 2011 Vision 2020: NYC Comprehensive Waterfront Plan, which calls not for protecting the waterfront, but for climate "resilience," the ability to withstand and recover from the disaster. Unfortunately, this may be the best that can be done for those living in the coastal sections of the boroughs that face the Atlantic Ocean.
So the Great Evacuation of August 2011 is a test. In its postmortem on the storm on September 5, the New York Times concluded that "by almost any measure, the evacuation was a success," but it did not report on the principal measure. How many people were left behind? Unlike New Orleans after Katrina, we won't know by counting the bodies. Not this time, anyway.
Douglas Hill, EngScD, P.E., Stony Brook University
Other posts in this series
Storm surge barriers: the New England Experience
Hurricane Irene: New York City's close call
Reader Comments
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When New Orleans was temporarily knocked out of commission after Katrina, the financial and logistic ripples were felt worldwide--and that's when the economy was relatively stable. Imagine, then, the world's financial center being offline for many weeks or months in the aftermath of the direct hit of a major storm, especially now when both the US and global economies are in such a precarious position.
Overhyped? Really?
Did my daily update & looked the world over..Navy has dropped 99L. NOAA still has a floater on it. Looking at some of the waves out there & the amplifying, deep digging fronts coming their way..may see another invest in the next 3-5 days. There is the wave at the Windward Islands that's a little higher than expected & that decent wave riding around 10N in the Central Atlantic. I'll give the latter the best chance but either have opportunity to at least be an invest at some point.
90B is new, 05A is a naked shadow of it's former self..
99S is new..impressive enough in moisture to get a floater (up in my blog).
Other note-able extratropical lows would be the 1009mb one N of Hawaii. & the 967mb low east of Greenland..that looks tight on ASCAT..Ya'll look out for that one in the UK & Norway in a few days.
2012 is gonna be a hellava ride, buckle up. Economic disaster is on the way, storms are gonna devastate, earthquakes, floods, people WILL start thinking the end of the world is coming....and it might just be...
That economic disaster you refer to is MAN MADE....and it ain't coming from any storm or maybe it will.....WE ARE ALL SO SCREWED!!!
It'll be called "Fallout"
Same thought here. Vulnerability of NY, NY is nothing new, so what's the deal now?
Just checking news on the High winds. From the Los Angeles Times... (edit)
More than 200,000 Southland residents were without power early Friday and numerous school districts remained closed as crews worked to clean up broken windows, downed trees and scattered debris.
Sounds like Pasadena got it. Disaster declared. Picture on the news page link resembles twisted tree like you'd see with tornado damage.
Jim Cantore was in Pasadena, for heaven's sake. Probably the most wind action he's seen all year.
:)
Tropical Cyclone Outlook
15:00 PM RET December 2 2011
=================================
Two broad low pressure areas are currently present just to the south of the ITCZ.
The first one is located in our area of responsibility between 10S-20S and 65E-80E. It is stretched along a northwest/southeast axis and show a poorly organized thunderstorm activity. It appears that the low previously monitored to the southeast of Diego Garcia is now dissipated within the eastern part of this broad low pressure system.
Latest SCAT data, surface reports and satellite data show that a new LLCC is currently located in the
western part of the broad system near 12.2S 69.2E at 1000 UTC. MSLP is estimated at 1004 hPa (according buoy 14043) and winds are in the 10/20 kt range.
Due to marginal low level inflow and east northeasterly shear (although it should gradually abate along the week-end), there is a very low potential for cyclogenesis within the next three days.
However, all available NWP guidance keep this low although the forecast period as it should slowly
drift eastwards.
The second one is currently located in the Indonesian area of responsibility. It is located at 0700 UTC near 6.0S 98.2E. Some slow development is possible within the next three days as it should move generally southwestwards. Current outlook call for a possible come in our area of responsibility Sunday night or Monday morning.
For the next 48 hours, there is no potential for the development of a tropical depression. It becomes
poor Monday with the potential arrival in our area of responsibility of the low currently located in the Indonesian area of responsibility.
Yeah I'm trying to find some info about it. they said the winds where pretty bad. the winds are gonna be bad nevada,utah and some other states. Does anyone have any info about this?
For what it's worth, I posted about it three or four times since Wednesday evening, and the only response was along the lines of, "Yep, sounds bad", so I figured there wasn't much interest.
Enjoy your Friday.
does anyone know anything about this?
Neapolitan, can ya tell me what's going on out there? I'm really not good at looking it up, don't know where to start.
edit: there is a subtlety between the import of awareness and spreading fear.
HOO WEE!
It seems like this is part 2 of the previous post. I am wondering if the main threat in the immediate future might be from the winter storms, as they were mentioned earlier as being the cause of flooding recently.
If added to the projected sea level rises and the progressive sinking of the land around New York, coupled with probable increased storm strengths both winter and summer seasons, it would seem imperative to construct some protective system to at least delay the possibilities of flooding.
A similar but smaller system was built in the London, UK, Thames estuary quite some time ago and has been used to prevent storm surges from the North Sea.
..click image
A place named El Cariso is showing a 195 mph wind gust!! Hmmmm....
--Harvey's max winds were raised from 50 knots to 55 knots.
--Harvey was a tropical storm for longer than thought; in fact, after becoming a depression on 8/21, Harvey regained tropical storm status on the morning of 8/22.
--Harvey's ACE was bumped slightly, from 1.235 to 1.655. Not much, but that's enough to leapfrog the storm over both Don and Arlene to assume 14th place overall for the time being.
China will never go to war with us, we are the only reason they have an economy.
NATIONAL WEATHER SERVICE LITTLE ROCK AR
700 AM CST FRI DEC 02 2011
...HEAVY RAINFALL EXPECTED SUNDAY THROUGH TUESDAY MORNING...
SYNOPSIS...
A SLOW MOVING COLD FRONT WILL PUSH INTO ARKANSAS THIS WEEKEND. RAIN
WILL DEVELOP ALONG AND AHEAD OF THE FRONT...WITH THE HEAVIEST RAIN
EXPECTED OVER THE SOUTHEAST HALF OF THE STATE. TWO TO FOUR INCHES
WILL BE COMMON ACROSS MUCH OF THE HYDROLOGIC SERVICE AREA...WITH
FOUR TO SIX INCHES POSSIBLE SOUTH AND EAST OF THE I-30/HWY 67
CORRIDOR.
GIVEN THIS MUCH RAIN...FLASH FLOODING AND RIVER FLOODING WILL BE A
CONCERN. AREA RIVERS AND STREAMS IN THE OUACHITA...LOWER
ARKANSAS...AND LOWER WHITE RIVER BASIN WILL BE THE MOST THREATENED
DURING THIS EVENT...WITH MINOR TO MODERATE FLOODING POSSIBLE.
EMERGENCY MANAGERS...MEDIA...AND ALL PEOPLE LIVING IN OR VISITING
THE AREA SHOULD PAY CLOSE ATTENTION TO UPDATED FORECASTS FOR THE
POSSIBILITY OF HEAVY RAINFALL AND FLOODING. REMEMBER...DRIVING INTO
FLOODED AREAS CAN BE FATAL.
FOR THE LATEST RIVER STAGE INFORMATION...FORECAST...AND WARNINGS
PLEASE VISIT OUR WEBSITE AT:
HTTP://WWW.SRH.NOAA.GOV/LZK
RIVER STAGE AND FORECAST DATA CAN BE OBTAINED BY SELECTING THE
RIVERS AND LAKES AHPS LINK UNDER THE CURRENT CONDITIONS SECTION.
QUESTIONS AND COMMENTS MAY BE DIRECTED TO...
TABITHA CLARKE
SERVICE HYDROLOGIST
NWS LITTLE ROCK AR
501-834-0308
TABITHA.CLARKE@NOAA.GOV
NATIONAL WEATHER SERVICE JACKSON, MS
133 PM CST FRI DEC 2 2011
...THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A FLOOD
ADVISORY FOR THE MISSISSIPPI RIVER...
MISSISSIPPI RIVER NEAR ARKANSAS CITY AFFECTING CHICOT...DESHA...
BOLIVAR AND WASHINGTON COUNTIES
MISSISSIPPI RIVER NEAR GREENVILLE AFFECTING CHICOT...EAST
CARROLL...ISSAQUENA AND WASHINGTON COUNTIES
MISSISSIPPI RIVER AT VICKSBURG AFFECTING MADISON...TENSAS...
CLAIBORNE...JEFFERSON AND WARREN COUNTIES/PARISHES
MISSISSIPPI RIVER AT NATCHEZ AFFECTING CONCORDIA...ADAMS AND
WILKINSON COUNTIES/PARISHES
ARC017-LAC035-MSC055-151-040133-
/O.NEW.KJAN.FL.Y.0014.111202T1933Z-111215T1519Z/
/GEEM6.N.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/
133 PM CST FRI DEC 2 2011
THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A
* FLOOD ADVISORY FOR
THE MISSISSIPPI RIVER NEAR GREENVILLE.
* UNTIL THURSDAY DECEMBER 15.
* AT 1:00 PM FRIDAY THE STAGE WAS 34.9 FEET.
* FLOOD STAGE IS 48.0 FEET.
* FORECAST...THE RIVER WILL RISE TO NEAR 42.5 FEET TUESDAY DECEMBER
13.
1. NORTH INDIAN OCEAN AREA(MALAY PENINSULA WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA(135E WEST TO COAST OF AFRICA)
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA PREVIOUSLY LOCATED NEAR 4.4S 99.1E, IS NOW LOCATED NEAR 6.7S 95.8E, APPROXIMATELY 655 NM OF JAKARTA, INDONESIA. ANIMATED MULTISPECTRAL AND INFRARED IMAGERY INDICATE AN IMPROVING LOW LEVEL CIRCULATION CENTER(LLCC) OF THE COAST OF SAMATRA. A RECENT 021443Z ASCAT PASS INDICATES THE WINDS AROUND THE LLCC ARE AROUND 15 TO 20 KNOTS WITH STRONGER WINDS LOCATED ON THE WESTERN SEMI-CIRCLE. UPPER LEVEL ANALYSIS INDICATES THAT VERTICAL WIND SHEAR REMAINS HIGH 20 TO 30 KNOTS. ANIMATED ENHANCED WATER VAOPER IMAGERY INDICATES CONVECTION DEVELOPING OVER THE LLCC, BUT THE VERTICAL WIND SHEAR IS INHIBITING DEEP CONVECTION FROM PERSISTING. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. BASED ON THE IMPROVING LLCC, PERSISTENT DEVELOPMENT OF CONVECTION, BUT HIGH VERTICAL WIND SHEAR MINIMIZING DEEP CONVECTION FROM DEVELOPING, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
(2) NO OTHER SUSPECT AREAS.//
NNNN
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