Our local genius of emergency preparation , Andrew (Susin Tolchin) Spano has denied that any disaster prep is needed for the Kensico dam. He also has proven that none is required for Indian Point, by pulling Westchester County out of evac drills.
I took the time to investigate, to see if Spano was right, and we should "All just float away" (Spano's words). As usual, I found he was wrong. Check it out:
South of the Kensico dam, there is no flat open plain waiting to absorb and disperse any flood resulting from a dam failure.Instead the dam sits at the head of the narrow, focused canyon of the Bronx River, stretching South from the dam,and running through the most highly populated section of the most highly populated region in America.
As residents know, out of this canyon there is truly no escape.All East to West roads in this area are small, twisting stoplight-ridden vestiges of old colonial paths.The only good roads run North to South - exactly the path of the water.
The water surface in the Kensico reservoir stands 355 feet above sea level. The dam stretches between two 400 ft hills,168 feet above the ground surface in the Kensico dam plaza. Therefore any wall of water leaving the dam will be 150+ feet high. Immediately South of the plaza,two more 400 foot hills contain this water, hemming it in at a 250' elevation, forcing it South to the North White Plains Train Yard,where it will pick up Metro North Railcars-up to 200 of them, and send them sailing like 80 ton surfboards.
These objects, and the 120'+ high wall of water will smash into the abutments of the elevated Cross-Westchester Expressway, turning it over, killing hundreds, and in addition closing a major arterial route from New England to the West. Leaping over the fallen Expressway the mighty torrent will bear itsload of railcars, 18 wheel truck bodies, propane tank trucks & passenger cars on again towards White Plains Proper.
At The White Plains Train Station the ground elevation is about 200' above sea level, so the water is dropping fast, and accellerating. At this point the Bronx River Canyon turns abruptly to the Southwest, and the crest, with its load of giant floating debris will resist the turn, and overtop the channel,obliterating both the Westchester County Center Building, and the White Plains Train Station.
South of the station, below the brow of Battle Hill is the famous hairpin turn on the Bronx River Parkway. Below this elevated span, the valley narrows and steepens. This will have the effect ofaccellerating the stream into a monstrous White Water rapid which will follow the old Bronx River Aqueduct South, uprooting the Hartsdale Train Station, and Barrelling into Garth Woods,turning its 150 year old trees into deadly missiles. It will roar into Scarsdale Station,the Garth Woods Apartment Houses and Our Lady of Fatima Church at about 300 miles per hour,easily sweeping them away.
At Crestwood, the historic Asbury church sits directly over the abandoned Bronx River Aqueduct, and so after surviving 200+ years, would finally disappear in the flood. The land surface at this point is 120 feet above sea level, so once again the water is barrelling downhill, and picking up speed.
At Tuckahoe, the channel narrows radically in the old Burroughs Wellcome Factory Sluiceway, and at this point, unfortunately,a condominium sits hard by the stream , as does the Headquarters of the Hudson Valley bank. These buildings will be overtopped by the constrained fury of thenarrowly channeled deluge, and will disintegrate, and head South.The Tuckahoe train station and town hall will be screened by theold factory buildings, but will be inundated up to the 200 foot elevation,drowning everyone in the town to a radius of 10 blocks.
Now comes a uniquely tragic episode. The mighty deluge, roaring southward at 300 miles an hour will enter Bronxville, and totally annihilate the Lawrence Hospital Complex, which sits in fact, directly on the Bronx River. None will survive. Patients, doctors,the elderly, the embattled nursing staff, xray machines , operating rooms,and 100 years of medical records will be turned into sludge,joining the rapidly solidifying debris field. (a watery debris field does not disperse as it goes, like a smoke plume. a watery debris field solidifies, and bears its contents downstream like a battering ram.)
Racing through Fleetwood and MountVernon in the tightly channeled Bronx River Parkway cut, between tall constraining concrete walls, the flood will topple the 60 year old Cross County Parkway overpass,which is some 80 feet high.It will fall spectacularly to the South,its rotten,spalling concrete legs long in need of repair, but never getting it, terrified motorists able to watch the sickening arc of its fall in their last pitiful moments of life.
At Wakefield in the Bronx, the tsunami will careen mightily into Misericordia Hospital on the East , and Woodlawn Cemetary on the West,ironically joining the newly dying with the long dead, for their last bit of camaraderie,on a 400 mile per hour slalom to the North River.Misericordia's xray machines will join Lawrence's xray machines, the Metro North railcars, the propane tankers, 18 wheelers & soccer momsas pathetic bits of dredge, shredding against the uprooted treesfrom Garth Woods, turning into a roaring, bloody, muddy stinking sludge of death.
The death-sludge, now careening forward at an incredible 400 miles per hour, roaring like a thousand freight trains will slam into Fordham University, and the Bronx Zoo, in a fraction of a second wiping out a hundred years of science and scholarship, and propelling scholars, wild beasts, and the death-sludge hard against the Cross Bronx Expressway. This is solidly built, and will not overturn. Instead the water and all its contents will rise in a mighty wall of water, overtopping the road,and spreading out in all directions into the narrow streets of the South Bronx,killing tens of thousands in a few minutes.
Finally, in the Swampy Flats between Clason Point and Hunt's Point, the torrent will lay out its creation for all to see- a railcar here, an elderly victim there, an 18-wheeler almost hidden in 7 feet of undiggable, irremedial life-sludge become death-sludge.
Gone will be two major hospitals, 3 major east-west arterials, most water into New York City, all rail traffic on the harlem line, which probably will be declared unrepairable and abandoned,all use of the Bronx River Parkway, whose pavement will have been torn out in half mile chunks and buried under yards of Mount St Helens type mud, all further use of the IRT subway, whose tranformer yards and switch houses will now lie in the North River, and up to 3 million dead. But they won't matter.
Why won't they matter?
They won't matter because they dont live in Bedford and they don't have Robert F Kennedy Jr pleading to save them, and because Andrew Spano thinks they should "Just Float Away". In point of fact, Spano is hiding just why he refuses to consider such an event. You see, the City of New York owns the dam, not Westchester County, so Spano has no budget for this disaster. So therefore it cannot happen.
When Spano answered Monique Rahaman at his "Regional Security Teach-in", telling her that dam failure was, in his words, "Not too likely", he was unaware that over 200 major dam failures had occurred in the twentieth century, making the likelihood of a dam failure a 100% certainty, once every six months on average, for a over a hundred years.
A major hurricane happens once every 30 years.
A world war happens twice in a century.
A space shuttle is lost once every 15 years,
but a dam fails once every six months, on average.
And that is without considering malicious intent.
SUMMARY OF FACTS:
With the surface of the reservoir behind Kensico standing 168 feet tall,
At 355 feet above mean sea level,
the first point of disaster analysis is to plot the 168 foot elevation line
on local topo maps, south all the way to Hunt's point.
All structures within this envelope will be destroyed, and carried south,
either polluting the North River, or piling up at some obstruction,
probably the multiple trestles of the Subway and the Cross Bronx Expressway in the
180th street area. The water would then overtop the pile of junk,
and inundate the tenemants of the East Bronx. Note that when impeded,
the water can kinetically rise ABOVE its original height, and the 200 foot
elevation would not be beyond reach. (make a swirl in your bathtub, to see what I mean).
Note also that this is not a plume, which lessens in intensity, but a solid
body of water, which will become even more solid by debris inclusion. The closest
analog to the Kensico disaster would be the Mount St Helens Pyroclastic flow,
which leveled a similar sized area, with a similar sized debris body in 1980.
The next analysis would be to use census information to count the bodies
resident inside the envelope. Certainly no less than 1.5 million, and
possibly as many as 3 million. Add to that the Real Estate Value,
and factor in the sewage treatment and garbage/chemical storage areas
which will be inundated, uprooted, and moved south at 300 miles per hour,
and it makes the World Trade Center event look like a fizzled firecracker.
No, Mr. Spano, we will not "Just Float Away"!!
To Andy Spano..
Heres what happened when the Croton Dam broke:
When the original Croton Dam was 95% completed, it was early spring after a very cold snow-laden winter, and the snow pack was high. The weather suddenly swung to warm (over 65 degrees) and after 3 days of warm weather, a thunderstorm and torrential downpour ensued, lasting most of a day. The snow melt coupled with the downpour overwhelmed the design parameters of the dam, and it washed away , with a wall of water taking houses, barns, trees, rocks, animals & people directly down to the Hudson river in about five minutes. This disaster and its debris field permanently closed the Croton river to navigation--prior to this it had been navigable up to the Quaker Bridge. The Good news in this was that the outflow path was short, before reaching sea level at the Hudson. The comparable path South from Valhalla to Hun's point is some 15 miles long, and has several million inhabitants.The wall of water would essentially follow the Bronx River Parkway, and would decimate Valhalla, North White Plains, Greenburgh (take Brodsky...please), Hartsdale, Scarsdale, Tuckahoe, Bronxville, Mount Vernon, Wakefield, Williamsbridge, Fordham, and points south directly into the head of the East River around Hunt's point. That's why you can't drive across the Kensico dam this week. Climbing the dam from the bottom, though, is real easy, especially for today's young people, with rock climbing skills. The Square white 7 foot patches visible on the front of Kensico dam are from the Fraternity brother who climbed the dam (either upward or downward) in about 1993, and painted large white frat lettrs halfway down the front, going completely from left to right-- these patches are visible today. Take a look, and good luck on your mission, Andy!!
Have many people been killed in dam collapses?
A: More than 1,350,000 people have been swept to their deaths by the roughly 200 dams outside China which have collapsed or been overtopped during the 20th century. Two large dams which burst when a massive typhoon hit the Chinese province of Henan in August 1975 left an estimated 80,000 to 230,000 dead. This disaster was kept secret by the Chinese government and was only revealed to the outside world in 1995. People have also died in earthquakes caused by the great weight of water in large reservoirs. A magnitude 6.3 earthquake caused by Koyna Dam in India in 1967 killed around 180 people. The following sites catalog dam disasters
http://www.antenna.nl/wise/uranium/mdaflf.html
http://www.ci.fort-collins.co.us/oem/dam-failure.php
http://www.abag.ca.gov/bayarea/eqmaps/damfailure/damfail.html
http://simscience.org/cracks/intermediate/death.html
http://www.geol.ucsb.edu/~arthur/Teton%20Dam/welcome_dam.html
http://www.scvhistory.com/scvhistory/stfrancis.htm
http://crunch.tec.army.mil/nid/webpages/nid.cfm
The Army Topo Engineering Center lists Kensico Dam NID No NY00051, 168 ft high
as a Category 1 or "High Hazard" dam
You may check this youself at:
Points of Contact:Technical Assistance:
U.S. Army Topographic Engineering Center CEERD-TR-A, ATTN: National Inventory of Dams7701 Telegraph Rd.Alexandria, VA 22315
rd1@tec.army.mil
General Dam Information:
Association of State Dam Safety Officials450 Old Vine Street, 2nd FloorLexington, KY 40507
info@damsafety.org
Riverkeeper said so in 1999:
The first comprehensive risk assessment of the 160-year-old water system was completed in December 1997 by Michael Collins, then head of the DEP's Police Department. The security review, developed in conjunction with the FBI, found that the entire system, which covers nearly 2,000 square miles, was vulnerable to sabotage. This report formed the substance of a 1999 report by Robert F. Kennedy of Riverkeeper, who declared our dams to be unsafe. In his 125-page report, Collins wrote that, "portions of this system are in a state of disrepair as a result of aging, maintenance neglect and security complacency." As an example, Collins cited the 900-million gallon Hillview Reservoir, which distributes drinking water to New York City and serves more people than any other reservoir in the country. Collins' study states that, "If a successful assault occurs at Hillview Reservoir, it could be a catastrophic event for the city. One could argue that it should be protected like Fort Knox but, at present, it does not even have the security of a local 7-Eleven." The analysis found so many areas of vulnerability in the water system that the consequences of sabotage range to catastrophic flooding that could destroy business and residential areas.The report particularly cites the Kensico Dam, which is 3,300 feet long, 307 feet high and holds back 30.6 billion gallons of water in a reservoir covering some 2,000 acres. The DEP rates Kensico as a critical element of the water system. According to Collins' analysis, "If Kensico Dam were to fail, the City of White Plains would encounter water depths of 70 feet within one hour of dam failure (dwindling) to 3.5 feet four hours after failure..." DEP Commissioner Christopher Ward said he did not believe the system's huge dams were targets, despite the lax security and the warnings in Collins' report, or that there was a threat of bioterrorism. A March 1997 study for the DEP by the Center for Risk Management of Engineering Systems, "Hardening Water Supply Systems to Reduce Their Vulnerability to Attack," stated that the Kensico Dam, if targeted by explosives, "would focus the force of an explosion and create more effective damage." Said Ward, "You are never going to be completely safe. There is always a scenario where something could happen.
