Showing posts with label maps. Show all posts
Showing posts with label maps. Show all posts

Monday, August 3, 2015

Wareham Hurricane Primer: Inundation And Evacuation



Wareham has a long and lengthy history with ol' Mister Hurricane. Just looking at that map above without knowing what it means, you can see that trouble would be afoot for ?ham if the barometer drops too much.

Wareham has taken beatings from Hurricane Bob, the Long Island Express, and a dozen other storms, and that's just in White Guy history. If you work in the native population, the numbers become countless after an eon or ten.

The 'Ham ( I really want to write a cop show for TV, base it in Onset, and call it "The 'Ham") suffers from the same problem which places like Bangladesh have.... it exists at the tip of a funnel. The funnel is formed by Buzzards Bay. That's the body-of-water Buzzards Bay, not the village part of Bourne... those people share the same Bangladeshian funnel problem that ?ham has.

Hurricanes, with both the wind and storm surge, push water ahead of them. That's actually what the storm surge is. It's not a problem in the middle of the Atlantic, but that water has to come ashore somewhere, and that somewhere is often at what they call the head of the bay. That's Wareham.

In fact, the "where" sound in Wareham may actually refer to "where the water goes." Water cares very little about washing over roads, cars, houses, people....  once it gets off the beach, we have a natural disaster on our hands.

You have two maps here, folks... the upper one shows Inundation, and the lower one shows Evacuation Zones. The maps are from June of 2014, and- to my knowledge- are the plan du jour.

"Inundation" is a nice, painless term that means "covered in water," but you can change it to "Deathflood" or "Sea Plague" if it gets the troops moving quicker.

They (these maps are produced by the National Hurricane Center) assume that Wareham gets a direct hit at high tide, and follow the (groan) SLOSH model of seawater redistribution that MEMA and others use. They are assuming worst case everything insofar as wind direction, phase of moon (check that, they use Mean High Tide), forward speed of the storm and everything else goes.

Those pretty colors are actually differing levels of devastation. I had a map/legend thingy in the Photobucket somewhere, but I'll just say that light green is a Category 1 storm, dark green is a Category 2, yellow is a Category 3, and red is a Category 4.

For a basis of comparison, what Wareham got from Hurricane Gloria may have been a weak Category 1 storm (she came ashore in Connecticut), the Blizzard of '78 was about a strong Category 1/weak Category 2, Hurricane Bob was  moderate Category 2 ("moderate" and "Category 2 hurricane" are kind of odd words to string together), old timers may have witnessed Hurricane Carol at Category 3, and The Great New England Hurricane of 1938 was a strong Category 3 made worse (Blue Hills got a 186 mph wind gust) by her forward speed.

The colors show which sort of storm will inundate which areas. Light green means you are hurting in even a weak hurricane. Any shift in colors after light green means that the storm will have to kick it up a notch to reach that area. Red areas are places that will only suffer- but suffer they will- in a Category 4 storm, the likes of which hasn't been seen by White Men in these parts. Hurricane Bob was our 11th deadliest storm ever in Massachusetts, in case you were wondering where your memories rank all-time.

The lower map, Evacuation Zones, is a bit easier to follow. They have three zones of evacuation. The third zone is reserved for storms we don't get, because I never saw the third color, and I looked at 30 town maps. The other colors break down as red = They Have To Leave and yellow = You Have To Leave, Too.

If you stare at the top map a bit an then stare at the bottom map, you'll get the basic idea of the Hows and Whys.

This is a frightening amount of Inundation territory. Wareham is home to 21,000 people. Almost all of them would be underwater in this scenario. To make it worse, these maps only show part of the problem. There will be high winds, downed wires, falling tree limbs, river flooding, sewer overflow, road washouts... you know, the whole nine.

I can leave the worrying to you. It's my job to provide the maps and some insight. My work is done here. Godspeed.




Hurricane Inundation Maps

Evacuation Zone Maps




Sunday, August 2, 2015

Bourne Hurricane Season Primer I: Inundation

                                Run To The Hills...

We got ourselves a look at the current evacuation zone and hurricane inundation maps for Bourne, and the results are quite frightening. The Cape Cod Emergency Traffic Plan isn't exactly comforting, either.
Cape Codders often consider Bourne to be almost inland when compared to a Nantucket or even an Orleans. Heck, we're technically on two bays, we're not even open ocean. Cape Cod itself is our barrier beach, and maybe not that much will happen to us if the barometer drops hard. That is the sort of attitude that gets a man and his family killed in Bourne.
I have personally heard an 80-something year old guy talk about houses washing down the Cape Cod Canal in the 1938 storm, about people drowning in their attics as they tried to claw through the ceiling with their bare hands, about 5 feet of water rushing down Main Street, about old-school fisherman tough guys from the Great Depression getting blown off their feet and hurled down the road, and about power being off for months afterwards.

Bourne has an Achilles Heel, and it is the body of water known as Buzzards Bay. Buzzards Bay is sort of shaped like this ^ symbol, and water funnels up into it. It is a distinct geographical feature that we share with Bangladesh, and it leads to extensive flooding.
Hurricanes have storm surges, which are a wall of water that is pushed ashore ahead of/with the storm. If you were standing with your toes at the edge of the water at high tide and a ten foot storm surge suddenly appeared, you'd be under ten feet of water. Imagine how far that water would reach inland in such a situation, and mix it with 6-12" of rain, river/stream overflow and sewer backups to get an idea of what an Inundation Map represents.
We are just as vulnerable to a big storm now as we were in 1938. We are actually more vulnerable, if you think modern medicine, more accurate forecasting (Boston forecasters have blown mega-storm forecasts in 1978 and as recently as 1991's Halloween Gale and 2010's Hurricane Earl, but they didn't know the 1938 storm was happening until it hit them), and greater transportation capabilities are offset by the fact that 170,000 more people live here now and still only have two roads off of the Cape.
We'll get to all of that in a moment, but first, let me hit you up with some links. They'll help you out with the discussion.
CYA, people. We live in dangerous times, and Bourne has been God's punching bag more than once.
We intend to cover Inundation Zones and Evacuation Zones. About halfway throuh the former, we decided that this would be a two-part special. Today is Inundation, tomorrow is Evacuation. If you are a Bourne resident or visitor, this is Disaster Porn right down to your very neighborhood.
I can play with this map all day, and I already have. It tells you what sort of hurricane would flood your neighborhood. They work by Saffir-Simpson scale, a la Category 1, Category 5 and what have you.
While I get the sense that some people would disagree with their findings, few would contend with the level of detail. You can check things not only to your town, and not only to your street, but also to your side of the street.
I had some rookie trouble getting the pics from their site to the Photobucket to here, and I apologize for the blurriness. I also apologize if I cut off the map right before it got to your house, I hate when people do that to me.
You can go to this link yourself and zoom right in on your own home, and I'd recommend doing so. It's always a wise move, getting a feel for the lay of the land around you.
To assess risk in Bourne, we'll go village-by-village.
**Yes, I'm aware that the map has my boyfriend and three Hooters waitresses on it. You get used to it after a while. Sorry girls... he's taken.
Buzzards Bay has 4 borders, and only one of them isn't liquid. Buzzards Bay (water) owns their South, the Canal bisects it, and Buttermilk Bay sits on the North and West. The trouble starts at Cohasset Narrows, out where the Massachusetts Maritime Academy is. They become inundated by a Cat-1, and you might be able to sink a boat by gouging out the bottom of it on the tallest building on Taylor's Point in a bigger storm.
It wouldn't take much of a storm (note: "much of a strorm" = "Category 2 hurricane") to inundate the Belmont Circle rotary at the mainland side of the Bourne Bridge. The rotary Capeside looks a bit better suited for Hell and high water, or at least the latter.
That trouble runs pretty much all from Taylor's Point through Buzzards Bay's Main Street area down to a bit past the Bourne Bridge. A Cat-2 storm would push the flooding over Main Street into the residential neighborhoods, and would inundate the police station, the fire station, and the Veteran's Community Center, which I presume is what they would use as a shelter. A Category 3 would be all-she-wrote for the Armory, which is the last place we could put refugees.
Bournedale, which is all wooded hills, would be untouched, save for the river flooding where the Herring Run meets the Canal. They would most likely lead the Cape in fallen trees and in boulders washing into roads, however. I live along the Bournedale/Sagamore border, on a hill, and that explains the relatively light-hearted tone of the article.
Sagamore and Sagamore Beach are basically Sagamore and North Sagamore. Route 3/6 is generally considered to be the western border. Sagamore Beach benefits mightily from Cape Cod's barrier beach effect, and only the direct shoreline is in danger. That danger would be immense in a bad storm, as there is nothing but sand between Cape Cod Bay and the first houses.

Sagamore would be at the mercy of a storm large enough to overflow the Canal. A storm of Cat-3 would flood into residential neighborhoods, although 6A would be spared up until the 130 intersection. The railroad and the power station would be fish toys in this hypothetical storm. The 3A part of Sagamore would be untouched by the sea.
Scusset Beach is Sandwich, so a Category 3 storm would end Sandwich's presence on the mainland, at least in an above-water sense. A much smaller storm would swallow up all of the revenue-generating parts.
While we're on the topic, I just want it on the Internet somewhere that we should trade south-of-the-Canal Sagamore to Sandwich for Scusset Beach, and I'd throw them a chunk of Bourne Village if they insisted upon it. It makes sense with the maps, with the cops, and with me. It would tie up a lot of loose ends.
Now, this destruction I've served up is bad. However, we have only gone through the mainland, landlubbing part of Bourne. Once you cross the bridges, it gets really dangerous.
Bourne Village is easy to describe. Once the Canal overflows, they are going to lose some houses. Houses on the Cape side of the Canal by the RR bridge would suffer heavily even in a smaller storm. As 1938 showed, the Canal isn't afraid to dine upon a few waterfront homes when the barometer gets low.
Where it gets sketchy is the if/when/where part of water creeping across and blocking Sandwich Road. Sandwich Road would be the Rubicon where a storm might start trapping refugees trying to get between bridges... assuming the bridges are open, as they presently are shut down when winds hit 70 mph.
Monument Beach, Gray Gables, and Mashnee all look to be completely under water in even a Cat-1 storm, with the inundation reaching County Road. These people would have to leave if the storm was coming, and they would, to their benefit, get to the bridges first if they were ready to move quickly when the deal went down
Shore Road looks to be where a regular-bad storm would reach, while worse ones would push past it.
Mashnee shares a problem with other parts of Bourne that we'll discuss in a moment, the problem of already being out in the water before the Inundation calculations start getting calculated.
Cataumet and Pocasset also have large sections of village that are sticking out into Buzzards Bay.
Wing's Neck, Mashnee Neck and Scraggy Neck all become a series of high-ground islands in hurricanes, and those islands are divided by hills in larger storms. Anyone riding out a major storm there is beyond foolish, although I'm sure that some of the hardcore have done it.
If an area like Sagamore Beach gets catastrophic storm damage, someone will eventually get a truck full of water or an ambulance out there soon enough. If the only road to land from where you live is, say, Scraggy Neck Road, they may have to carry your people out on boats or helicopters.
Flooding looks like a sure bet to close Shore Road and Red Brook Harbor Road.
Cape Cod's other towns have similar problems. The entire coast of Cape Cod is subject to inundation. Northern Cape Cod's shoreline is especially bad at Barnstable Harbor and Yarmouth Port, while the sea's push inland against the Nantucket Sound side would move exponentially according to storm intensity.
Route 28 would be inundated from the 28/Main Street merge in Hyannis to South Harwich in a strong storm. 6A gets covered in Sandwich and again in West Barnstable. Route 6 would need a James Bond car from Provincetown to Wellfleet
Just due to the lay of the land and the lack of overflowable rivers, Cape Codders can avoid flooding by moving inland a mile or so. Duxbury or Wareham are far, far more at risk for inland inundation than Cape Cod is. Our greatest danger is the wind, but that's a whole other article.
Again, Cape Codders can generally escape the sea by moving inland, but that's starting to bleed into tomorrow's evacuation article.
Speaking of escape routes....
The South Shore can divided in half. Much of it is protected by Cape Cod, one of America's biggest barrier beaches. This southern South Shore is also a relatively straight coastline, with few Bangladeshian water funnels. From Sagamore Beach to Plymouth Harbor, areas where coastal flooding would reach more than 100 yards inland are few.
At this point, you amazingly have to look to Provincetown for a trend. Imagine that you are a big ocean wind. You are moving from east to west at 125 mph. At a certain latitude/longitude, the first thing in Massachusetts you will hit is Provincetown. Above that latitude, it becomes Duxbury and Hull. Where the wind goes across the water, the storm surge is sure to follow.
Duxbury, Kingston, Marshfield and Scituate are also estuaries, meaning that there is a lot of salt marsh behind the barrier beaches, and salt marshes flood very easily in storms. The end result is all that nor'easter flooding you see on the news. A stretch of coast from Duxbury to Scituate inundates heavily, with houses on Duxbury Beach frequently finding themselves effectively a mile out in the ocean when the marsh floods in even cupcake storms.
The North River is unique in that it would bring coastal flooding as far inland as Hanover and Pembroke. Pembroke is funny because, when you buy a house 15 miles inland, you don't really expect "pumping water from ocean storms out of your basement" to be part of the bargain. However, the South Shore doesn't play fair.
If it makes Hanover residents feel better, a storm bad enough to push water damage to you will probably have blown your house down like the Big Bad Wolf long before.... so, like, no worries. 
The South Coast is the opposite of the sheltered side of the South Shore. They get the surf pushing up from the South Atlantic, and they take the landfall in many cases. Rivers empty there, and all of the land is relatively low-lying. It is where the storm surge smashes into Massachusetts.
A swath of coastline from Mattapoisett to Marion would be soaked several miles inland in a big storm. The Sippican River confluence, the Acushnet River Valley Golf Course (which is just below New Bedfords reservoir) and Tihonet Pond would all get ocean storm water in a Katrina-style storm.
Route 195 would be submerged from about where Tabor Academy is in Marion to the Weweantic River in Wareham. This detour-by-God also occurs in what looks to me like the region that is most at risk during a large storm.
Wareham gets her own paragraph. If the storm gets bad enough, all of Wareham east of Wareham Crossing would be underwater to some extent. Route 25 would be impassable from Wal-Mart to Wareham Crossing. Water could push 3 miles inland, to the cranberry bogs off of Route 25. The entire Cranberry Highway business district would be underwater.
If the storm gets bad enough (Category 3 or higher) and made a direct hit, Wareham would suffer worse than any region of the state. It would take years to recover.
In closing, we just want to remind you that Massachusetts is a dangerous place if a hurricane is coming, Cape Cod and the South Coast are particularly dangerous spots in Massachusetts, and Bourne is a particularly dangerous spot on both the South Coast and Cape Cod.
Residents or even visitors should study those maps, learn them, know them and live them. They should check back now and then, to see if any relevant opinions have changed. This is information you should be fully aware of.
Having your house wrecked by a storm sucks pretty hard, but what sucks worse is getting killed while it happens. We need your site visits, and we care about you... so keep informed.