Examining Wave Attenuation Devices

We're talking Wave Attenuation Devices with Fred Dorr today.

Remember, I'm a sportswriter by trade. My entire expertise on the matter we're discussing today boils down to:

1) I grew up on a beach

2) The house was on a seawall

3) I therefore have a base knowledge of waves-crashing-off-walls

4) Even with no scientific/academic training, I have more experience watching waves hit walls than many people who are authorities on the matter.

It's all downhill from there. My science is awful. I taught Science one year, and the highlight there was when I let the kids handle liquid mercury. I had to throw out and then acquire new versions of 10 school desks.

I mention all this because I'm interviewing someone who works in a field that may spark some interest among coastal residents. This is why I am, from this point on, stealing text wholesale from his website.

Also, I conducted the interview via email. It saves me from taping phone calls like a divorcing couple, and it lets Mr. Dorr speak directly to you, in a sense.

This is also why I am not challenging any of his answers. I'm just showing you some new technology, and you can decide if it will work on Duxbury/Humarock/First Cliff/Horse Neck/Scusset Beach for yourselves.

What is a WAD?

A WAD (Wave Attenuation Device) is a three sided, hollow, concrete pyramid with holes on all three sides and one on the flat top.

WADs do not come in any one size. They are designed according to the conditions at a shoreline site. If, as in the case of Scituate, "they " wanted to deploy WADs at Minot beach, Peggotty, and Humarock, then quite likely there would be three different designs and perhaps three different sizes.

The design and size depend on the conditions at the deployment site. These conditions include ocean bottom, tide heights, astronomical tide heights, storm surges, weather direction, wind speed, storm intensities/frequencies and other factors.

Scituate

The Science of a WAD:

WADs do two things.

First they knock a high wave down to virtually smooth water.

The second thing they do is to remove energy from an ocean swell. They do this much the same way that the aerator on your sink faucet does. If you didn't have that aerator on the faucet the water would come out in a big blast. The aerator only allows the water in the pipe to get to your sink via very small holes. Therefore each of the water streams contains very little energy.

On the ocean side of a WAD array, the turbulent oceanic swells have picked up some sand and carry it in suspension through the WADs.

However, because the WADs reduce the energy of the wave, the sand falls out of suspension and settles on an eroded beach. If there is sand available in the near ocean, if we have a few nor'easter and if we had an array of WADs, we could over a short period of time (1-3 years) have a new dry high tide beach.


Seafood Farming?

In the background are fish havens they resemble WADs except they do not have a flat top or a hole in it.

They are mass produced in three sizes.

They are deployed in small arrays; circles, squares, triangles, etc. They attract fish and promote organic marine growth.

From what I have read they are very effective in increasing a fisherman's catch.

Q)  What makes the WADs better than a conventional Massachusetts seawall (like the Duxbury Beach one in the picture above)?

That's a short question that has a long answer.
1.  Waves under cut the sandy edge  (TOE) of a seawall
2.  WADs knock down high/tall waves to calm water.  When I asked Scott Bartkowski if WADs could knock down a 20 foot wave his reply was we have killed 29 foot waves.
3.  If there is sand available in the near shore up to 300-500 feet then during storms that sand, with the help of WADs, will migrate to the eroded beach and replenish it.
4.  When a beach gets fully replenished, the waves will not reach the seawall.  If a wave cannot reach a seawall there can be no damage to shoreline structures.

Sandwich, MA

Q) How do the WADs not get filled up with sand and stone? Would they be more, less or equally effective when filled or partially-filled with sand and stone?

In the course of doing their work the WADs do not get filled up instead they break the wave energy down into little pieces so to speak and the sand actually moves through the WADs.  If one snap shot were taken of the entire process then you would say that the WADs were filled up with sand.  Go to WADs Work 4 Beaches on face book and look at the video I have posted you will see what I mean.
When a beach is fully replenished then the municipality should get a barge and a crane go out into the sea and move the WADs farther out  and make a larger beach.


What sort of impact-force testing did you do on the WADs, i.e. waves picking up Ottoman-sized boulders (see "Bert's, Plymouth") and throwing them off WADs?

1. When Living Shoreline Solutions does their scientific investigation, they look at what's on the ocean floor, ferocity of storms. storm surge, astronomical tide effect, beach slope and a myriad of other parameters. They design four applicable WADs for a specific beach that will do the job of attenuating "its" waves.   If there are rocks on the ocean floor then the thickness of the wall of the hollow WAD is increased.  Understand that the concrete used is marine grade and reinforced with fiberglass shreds.  As regards to the event at Bert's   I guess my only answer to that is Poo happens.

Ocean Bluff/Brant Rock

Would fish swim into the holes during high tides, get trapped there when the tide went out, and then stink like stank on a hot summer day?  Can you put fish-filters over the holes and not diminish the effectiveness of the WAD?   

There is no need for keep the fish out of the WADs.  The WADS are hollow.  Fish can swim in and out of WADs.  In the gulf coast  LSS makes a series of Fish Havens for commercial fishermen.  They have reported significant increase in their harvest due to the effectiveness of WADS.  WADs are also used to promote oyster growth.


Do you put these WADs where conventional seawalls stand in relation to the high tides, or do they go offshore some?

Duxbury Beach

Generally the WADs are put in the water perhaps fifty to 100 feet beyond the low tide line.  Exactly where depends on a number of factors that are determined by LSS's scientific investigation and the needs of the client.


Is it possible to perform patchwork repairs on WADs somehow?

I am not sure I know what you mean by patchwork repairs.  If you mean to repair a WAD that has been damaged.  I do not know the answer because there have not been any cases of WAD failure in seventeen years.  Caution must be used because the primary market for WADs is in the south and the Caribbean, where there are no rocks.  If you mean can short (25-100 feet) arrays of WADs be put in place.  The answer is yes but the  overall project must contain several arrays because of a cost/profit problem.


This might be silliest question you've ever been asked in this field, but could a town order WADs in different colors if they so desired?

No it is not the silliest but it comes close.  There have been WADs built with rocks imbedded on the top to simulate a nearby breakwater.  I suppose if someone wanted a puse colored WAD array that could be done--at a price of course.

Green Harbor

Do you take any barnacle-prevention measures?  

WADs have three purposes--Attenuate waves, replenish beaches, and provide marine habitat.  I guess that means that if barnacles are going to grow on a WAD the people will have to deal with it.


Do WADs work if the water level gets higher than them?

Extraordinary question.  A swell is essentially rotating water much like a basket ball rolling across a gym floor.  If the bottom of a swell collides with the ocean bottom the swell turns into a breaker.  When a wave breaks it begins to lose its kinetic energy.   Wave height is measured from the bottom of the trough to the top of the swell

Kingston

If an array of WADs is in 12 feet of water and a swell of 13 feet comes by, the bottom of the swell will hit the top of the WAD causing the swell to begin to break.  If the ocean bottom on the beach side of the WAD is less than 13 feet then the swell will really break and lose all its energy.

In the process of losing its energy any sand that was in suspension will be deposited on the beach.  That is like trying to stir a glass of iced tea with five teaspoons of sugar in it.   As long as the tea is being stirred the sugar will stay in suspension.  But, when the stirring is stopped the excess sugar will settle to the bottom of the glass.   That is how a beach is replenished.


What sort of aquaculture can someone perform with a WAD? 

 I know that oysters grow very well on WADs,  I have seen pictures of fish in and around WADs.  In fact two hours after a WAD array was deployed at Negril Jamaica on a barren ocean bottom there were fish "sniffing" around looking for a good place to stay for the night!  I suspect that WADs would make a good hidey place for lobsters


How large of a wave would be required to move a WAD?

The actual answer is no body knows.  In the seventeen years that WADs have been deployed all over the world not one has ever been moved from the place it was deployed.  That is because of its design.  Hollow: water goes through a WAD.  A WAD has slanted sides.  A WAD is a three sided pyramid.  So the water goes up, and through WAD, and can't push it around.

Nantasket Beach

How tall do you make the tallest of your WADs?

All WADs are site specific.  For instance in Scituate, my town.  If the town were to WAD North Scituate Beach, Peggotty and Humarock there would likely be three different designs.  So far WADs have been as short as four feet and as tall as 12 feet.  They have weighed as little as 450 lbs to as much as 21,000 lbs.  I asked Ping Wang PHD University of South Florida who has done some Attenuation testing for Living Shorelines, the following question, "Could a WAD be designed to replenish a beach and at the same time prevent any shoreline damage regardless of the height of the waves.  His very short answer was "YES".


Is one mile of conventional Massachusetts seawall more or less expensive than the same distance of WADs?

Brant Rock/Ocean Bluff

Another fabulous question.  Scituate is or will be building a seawall 700 feet long.  It is expected to cost about $4,000,000 That works out to about $5700 per linear foot.  I have to stop for a moment here.  A seawall is necessary to keep calm high water from flooding the local area.  The concerns of sea level rise can be accommodated with a seawall.  But an array of WADS attenuate the waves.  On the ocean side there might be 12 foot waves.  On the shore side of the WAD deployment the waves might be 6 inches high  The current cost of a double row deployment of WADs is approximately $1,000 per linear foot.  I think that equates to an 80% saving.



Is it possible to buy WADs for personal use like forming a semi-circle in front of your house?

s soon as you said the word "possible" the answer is yes.  BUT you would have to ship them from Florida.  You would not have a choice in shape, because they do not manufacture them in a factory and then ship them from a stock pile.  Living Shoreline Solutions designs a site specific WAD, fabricates the concrete molds in Florida then ships the forms to the site.  Once here local labor assembles the forms and a local concrete company provides the concrete.  Then someone either has to hire a barge with a crane or a very big front end loader to deploy the finished product..  In addition the state owns the water, you would have to get their permission.  From what I understand that takes at least a year.

 I have enclosed two files, which are pictures that I plan to use in the article. One picture is of a seawall in Duxbury, which is what I have in mind when I say "conventional Massachusetts seawall." The other is of the White Cliffs Country Club in the Cedarville section of Plymouth. What could WADs do to stop erosion of those sand cliffs?

I have not yet seen your pix but I know that when it comes to cliff erosion, although WADS have not been used in that particular situation.  I have to add here that no WADs have ever been deployed in the waters of Massachusetts.  I have about 20 years left on this good earth and I intend to use every one of them to get WADs into Massachusetts waters.

Back to your query.  Put WADS in the water the scientifically prescribed distance from the toe of the cliff and if there is sand in the near shore then that sand will be transported to the space between the WADs and the toe of the cliff over some reasonable short period of time.  Perhaps 1-3 years.  In that time the beach level will rise above the height of the WADs and the waves will not reach the toe of the cliff.  If the waves cannot reach the shoreline there can be no further erosion except by the rain.

Again go to WADs Work 4 Beaches in face book look at the five videos for proof that they work.

Seawall Repair In Marshfield

Marshfield fights back against Poseidon this week, as they scramble to repair ruined seawalls before nor'easter season kicks in.

They dodged a bullet last week, as a powerful storm battered the coast for several tides. It never really got biblical however, and things appear to be sailing along well enough this week.

The town is fixing 1000 feet of seawall, mostly along Foster Avenue. It is replacing a wall that has been up since 1931. Recent storms have smacked it around, with the dark spectre of Attrition also having a loud say in matters.

There's no need to fear... FEMA (or the US Army Corps of Engineers, or the DPW) is here. Your tax dollars at work, as they say.

Left without maintenance, these walls would crumble into the sea. When that happens, it opens up the houses of that part of town to direct wave impacts. It also brings about great inundation. Relocation would involve re-settling 10000 souls or so.

That also means losing valuable property tax revenue, business money, jobs, tourist loot and any other of the zillion permutations that would come with telling the Coasties to eff themselves.

It's a lot like gun control.... ideally, there would be no development in vulnerable coastal areas. However, once you have it, it's easier to try to regulate it than it is to go door-to-door seizing property.

"Easier" in this case involves millions of dollars in seawall repairs, but that's cheap when compared to worst-case scenarios.

Joe Deady took the non-blurry, useful pictures.

This wall will be two feet higher than the present wall, and 84 years younger. They'll be using that, uhm, like, modern concrete or whatever they put in that wall. Vauban, I am not.

This maritime Maginot Line is Marshfield's magic against Mean Momma Mer.

Marsh Vegas, depending on how the storm winds blow, sort of alternates the title of First Town That Atlantic Storm Waves Hit Without Breaking On Cape Cod First between themselves, Scituate and Duxbury. This means that she takes heavy shots from the storm waves, and they kinda need the 2015 version of the seawall.

The town (through a loan from a state seawall fund) will split the costs of the project with the state, which will provide half of the necessary cheddar via a grant.

Total cost? $3.94 Million.

If this wall were built by the Donald, it would be taller, thicker, and deeper in the ground... and Mexico would be paying for it.

However, Vegas was happy to pay their half of the loot. Seawalls are like divorce... they cost so much because they're friggin' worth it.

The locals allowed the town some eminent domain mojo, so they can do future repair and maintenance work. From what I saw of this in Duxbury, it may cost you a foot of the lawn if they have to dig down for some maintenance.

That's a small price to pay for a wall that I'm pretty sure is thicker and tougher than the wall in Berlin that the Soviets used to keep the eastern Nazis penned up.

The whole wall is there to protect the Port-a-Potty, which is actually a cleverly-disguised Stargate.

Hawk-eyed readers will notice the 2015 date carved into the top of the stairs. I was gonna park and get a better picture, but the locals are sort of touchy about stuff like that.

Vegas had a tough week, with murder and nor'easters dominating the local news. The people of this particular neighborhood also have had a lot of heavy equipment erecting a Soviet-style cement project just outside their windows. These are the very last beach days, and they've had a few weeks ruined by both storm prevention maintenance and the storms themselves. I didn't want to throw "some moron journalist parked in my road" onto that list.

I never went to school for Journalism, and for most of that time where real reporters were learning Ethics from some professor, I was out learning how to break into cars and stuff like that.

However, I try to be a seamless and respectful addition to any neighborhood I may be visiting.

They still have a lot of work to do for a project that is supposed to be done by December.

Today's entertainment was on 13th St, and they have to get down to 9th for this phase of the project They eventually will go down to 3rd, but I don't have an ETA for that one.

Even if you aren't from Vegas, you should pay close attention to how things go down here. Massachusetts is lined with seawalls, and they cost a lot of money to repair.

Feel free to check our very-much-relative article on seawall repairs that we posted up on the world last summer.

Marshfield is laying the blueprint that a lot of towns may be following as their ancient seawalls fail. This could be happening in your Duxbury or Falmouth beach neighborhoods soon enough.

Otherwise, this could be happening...

Coastal Storm Clean-Up Notes

Sara Flynn on the camera, Sara Flynn's dog on the stick.

This last storm was fun to take pictures of, but it was a D+ grade storm historically, maybe a generous C if you value Staying Power. The dog enjoyed it heartily.

No one, except the guy I photographed jumping the Sandwich boardwalk on a parasail, is going to look back on this storm in 20 years with anyone who will remember what he was talking about. It doesn't merit historical consideration, other than the tragedy down in the Bahamas with the MMA kid.

However, even minor storms can mess up the neighborhood pretty nasty, and things will be a bit ugly until Toil and Tide smooths everything over.

We'll try to give you an idea of how the coastal people deal with storms.

This is an old picture, from a 2006 Duxbury nor'easter, To my knowledge, there were no houses torn apart in this last storm.

If the storm is bad enough to take houses, it goes without saying that the cleanup will be lengthier and more complicated.

Some storms can even alter the look of the neighborhood forever. To keep it Duxbury, I can recall the Blizzard of '78 being the end of the road for cottages in front of the dunes. The 1991 Halloween Gale knocked over the last of the 1950s-style cottages, and future gales will put the rest of the neighborhood up on stilts.

Again, this storm wasn't a home-killer. We're just establishing one end of the spectrum for the discussion.

The next level of storm is where the houses are up, but the road is ruined. This is the Ocean Bluff/Brant Rock area, after one of last winter's blizzards. That's not a dirt road, that's heavily-used and trust-me-it's-paved Route 139.

The ocean, when it moves from shoreline to street, isn't just water. It is moving large piles of sand and stone with it, as well as anything that might be in the yard of whoever owns the land the ocean is washing through.

When I was trapped in my house for the Halloween Gale, you couldn't stand in front of a window, even on the second floor, when waves were breaking on the house. Each wave would slam a Shirley Jackson story worth of stones off of the house. That's why you board the windows up, player.

Those stones also wash past the house, and that usually puts them in the street.

Sand also shifts, remember...

This was the most damage I saw working the Sandwich-Barnstable-Yarmouth-Dennis run during the storm last weekend. Some DPW guy can sweep that ish back up onto the dune or whatever happens to it in this town.

Duxbury usually has the other sort of problem, with the ocean slicing through from ocean to bay. That makes parts of Duxbury Beach- as well as Saquish, where people live- into islands. Most of the town's effort after the 1991 storm involved making the beach whole again.

Otherwise, people get cut off, supplies get low, panic ensues, and the people from the Gurnet rise up and slaughter the people of Saquish for food and goodies.

Even tony Sandwich takes her lumps now and then.

Sammich is located on the wrong side of the Cape Cod Canal jetty, and it gets very little replenishment sand from more northern towns.

Prior to the construction of the jetty, this was the sole benefit that Sandwich gained from nor'easters. Once the jetty was up, Sammich was having sand washed down the beach from them without getting any sand washed down to them.

This eventually leads to large chunks of Sandwich being claimed by the sea. The sea then starts touching things that she isn't supposed to be touching, like highways.

It's probably not going to come to that on Route 6A, at least from what I saw this weekend. There were some houses taking shots, and I'd bet that they lost a lot of sand.

If the street an the beach got messed up, you can bet that the wall that was supposed to be protecting the street has been compromised.

Seawall repairs are ugly business, for several reasons. One, if you need them, you most likely just had a damage-doin' storm. Two, seawall repairs are costly, with coastal towns sitting on potential seawall repair bills running into the millions. Three, there will almost always be a fight between homeowners, the town, the state and the US of g*d-damned A over who will be footing the bills for the seawall repair.

I am related to at least one guy who had to run down to Town Hall and wave deeds and contracts in their face before getting off the hook for thousands of dollars worth of seawall repairs that the town was supposed to pay for.

You have to watch the towns, as they try to get off "cheap" on the repairs now and then. Duxbury, which can hardly plead poverty, had a wooden seawall until the mid-1950s.

This is more of the Brant Rock/Ocean Bluff damage from last winter. If the elements and the budget won't let you build a fancy seawall, a bunch of boulders will have to do.

You just want something tall enough to slap down even huge waves, and you want it heavy enough to not be washed away when the Atlantic Ocean leans on it. If a little bit of water gets by it... well, hey, you live at a beach, right?

If you don't build a seawall, the ocean gets to tee off on you for 5-12 waves a minute for 3 hours of nor'easter tide, twice a day, any time the pressure drops. You want to try to avoid having that happen.

Seawalls are like divorces.... they cost so much because they're worth it. The town and state will complain, but it will get fixed in the end. The alternative- again, like the divorce- is too ugly to countenance.

The seawall houses in Duxbury are known for their beautifully maintained lawns and just-like-God-planned-it soft sand yards. Oh, wait... this is a post-blizzard shot of Duxbury Beach.

I swear to God that one of those houses in this picture above (the foreground, with the ice) is owned by a golf course groundskeeper, and his lawn is kept at putting-green-trim levels all summer.

In order for that to happen, you have to shovel (or hire someone to shovel) the beach back on to the beach. My yard on Ocean Road North would pick up what I would conservatively estimate to be 1000000000 rocks every nor'easter.

Rocks are handy to have around if you, say, need to fill large holes in your lawn.

Once the yard is cleared, it must be repaired.

Even after you fill the large holes (snow doesn't count, lazybones!), you still have problems. All of your grass has been washed and soaked on salt water.

The Romans, after razing Carthage, covered the ground with salt and sea salt. They salted it down because, as Sam Kinison said, "Nothing grows in sand, nothing's gonna grow in sand!"

Grass is no exception, which is why beaches tend to be sandy. If you want the grass back after a storm ruins it, you have to skim the top layer of soil and replace it with unspoiled topsoil. Then you plant the grass, and then you see if you removed enough salty soil.

This is why some people say "Screw lawns," and just go with natural sand yards. It turns out that these also require tireless maintenance. I did that with the patio near the seawall, as we would lose the front 10-20 feet of lawn with every storm.

This wonderful beach scene, as we noted in a previous article, would be perfect sand-water-dunes-lifeguard chair Cape Cod if this were not the parking lot of Sandy Neck Beach.

It'll all wash away at some point. It's marshy over there, and the DPW can sweep up and re-deposit that sand where it belongs. A parking lot is less of a touchy maintenance job than that of a million-dollar Hyannis Port beach house. You can't just let the Kennedy Compound drain, and then hire some townie to sweep it up whenever.

This can be touchy with October storms, as no coastal resident with any brains makes yard repairs on the nor'easter damage until late April. June through October is hurricane season, but October through the Ides of April is noreaster season, and we get several storms a year.

The beach suffers during those storms. People like the natural aspect of a soft-sand beach, in theory. In reality, "natural" beaches look a lot more like the picture with the dog at the beginning of the article.

The tide will take care of the lower beach, but the upper beach can get a little bit ugly.

Anyone who lives on a seawall knows this scene, represented perfectly by Duxbury Beach.

Several somebodies let the storm sneak up on them, and didn't take their stairs up (in the local patois, stairs are taken "up" onto the seawall, as opposed to being taken "down" from the seawall) in time. The stairs bang around in the surf until there isn't a seawall to prevent them from being tossed up past the wave-wash.

Eventually, you sneak on the beach with a Jeep (the "Duxbury Cadillac" of legend, in case you heard the term and never knew the reference), tow the stairs back to your house and hopefully store them a little more securely.

Duxbury Beach gets lots of odd stuff washing up. Every now and then, a barge loses a cargo container over the side, whch busts open and disgorges her contents into the sea. They eventually wash up on the beach somewhere. One winter, it was oil filters. Another winter, it was Nikes. If they had EBay in 1980, I would have sold more sneakers than that Air Jordan motherf***er.

Lobstermen get caught slippin', too.

For reasons I don't know but that some salty dude (or dudette, the only lobsterman among my Facebook friends is a girl known to me as Tornado) could tell us, wire pots don't wash ashore as much as wooden pots do.

When I was a kid, we'd go out after every nor'easter and snag lobsters out of the wooden traaps that washed ashore. We'd get several dozen this way, as pots, buoys and so forth were all over the beach.

You never steal the pots, however, and even the buoys were a rough proposition. I don't know if lobstermen can shoot you for touching their gear, but I know that many think they can... and that's all that will matter if the heat comes out on you, friend.

This is the Mystic River, courtesy of Paul Walker... no, not THAT one.

While this isn't ocean damage, what you see here are leaves. Those leaves, still green, should be up in a tree, getting ready to be in my fall foliage shots.

If those are lily pads or something, just try to work with me here.

Massachusetts, and especially Eastern Massachusetts, doesn't really get around to fall-foliaging until late October. Some places on Cape Cod (I noticed this while bell-ringing at the Sagamore Christmas Tree Shoppe) don't even go over until mid-November.

That overlaps with the October-April nor'easter season, and is one of the many reasons why coastal Massachusetts isn't really top-notch foliage country. We rock pretty hard compared to, say, New Mexico, but New Hampshire people laugh at our foliage... they LAUGH at it.

Of course, they don't have ocean storms up there, so they can just shush now.

When The Levee Breaks...

(Editor's Note: This article is from about 5 years ago, we diggin' in the crates...)

The Boston Globe and Google Maps are doing a cool service with this map of Massachusetts seawall conditions. Clicking on the individual areas lists the location and repair costs. Every seawall pictured on that map would cost $160 million to repair.

You can see the real thing here at the Globe, but I took the liberty of pasting a few shots of local areas for educational purposes only.

The map shows who has seawalls. The color code is basically Green meaning high quality,Orange meaning poor and Red being critical/non-existent.

The Outer Cape has her own seawall, that being a mountain of dunes. They were what Massachusetts defended herself with before the people era. Anyhow, that's why there are no seawalls of any note on the outer Cape.

They didn't have any info on Nantucket and Martha's Vineyard. I'm sure there are some localized seawalls, at least.

Note that the lower Cape seawall system is designed to stop hurricanes, while the South Shore's is designed to stop nor'easters. That's not 100% exclusive, but it's a good rule of thumb.

Falmouth is heavily sea-walled, and another strip runs off and on from Yarmouth to Chatham.

Seawall repairs are costly. Provincetown alone needs $5 million in seawall repairs. We're coastal people, and we have coastal problems. Things will only get worse if that global warming/sea level stuff is true.

Barnstable is very much unprotected by seawall, so they at least may get to dodge some of this Cost Bullet. They may be penny-wise and pound-foolish, but time will tell.

I'm no expert on the Cape's specific coastal areas, so I'll leave it to you to draw your own conclusions. If you have your own observations, leave them in the comments section.

I did some zooming, and isolated the two wall-iest areas of Cape Cod.... Here's one of them, the Falmouth/Bourne/Sandwich/Onset area. Everything on the map below would cost about $50 million to repair.

Falmouth is obviously prone to terrible tides, and the extensive seawall construction speaks volumes. The areas of Bourne and Onset were devastated during Hurricane Bob, right about where that hurtin-for-certain seawall is.

Much of that seawall is in need of repair. Those repairs will be costly. $50 million dollars = costly. Those repairs are small change against what losing miles of beachfront property would mean in taxes and tourism.

Estimates include seawalls, jetties and anything else armoring the coastline.

The run of seawall that goes from Bourne Pond to Jeweler's Road in Falmouth adds up in several increments to equal $3 million in necessary repairs if you throw in the nearby Eel Pond seawall. 

The seawall on Ocean Avenue to the Great Pond area of Falmouth needs $3 million in repairs.

Falmouth Heights needs $4 million in seawall repairs.

Lewis Point in Buzzards Bay needs $500,000 in repairs.

Onset is looking at $1.5-2 million in repairs

Here's the Yarmouth-Chatham run... price tag: $36 million or so.

Red River Beach in Harwich to Cockle Cove in Chatham needs $1.5 million in repairs.

Wychmere Harbor needs almost $2 million in seawall repairs, as does West Dennis Beach.

A series of seawall repairs from Parkers River to Beachwood Avenue in Yarmouth will surge well past $2 million.

Town Fish Pier In Chatham needs $500,000.

I'm not sure if the Wampanoags built seawalls. Native Americans tended/tend to be more reasonable than Europeans, and most likely just didn't settle dangerously close to the beaches.

The picture below is my hometown, Duxbury Beach. I'll focus on it because A) I'm very familiar with it, and B) I have some pictures of it. It runs from the Gurnet Road area of Duxbury to Green Harbor.

The seawall shown via the stripes of different colors protects about 1-2000 people, depending on the time of the year. The Southern half is sparsely populated, making up maybe 3-500 of the total figure even in the summer. The seawall repairs will cost well over $6 million, mostly to the north (and some of which is off the map), in Marsh Vegas.

The red area on the map is a football field-sized gap between the Duxbury seawall and the Marshfield seawall. The Globe reported that there was wall there at some point that has disappeared, but no wall has been there since the 1960s. I'll ask around, but no one I know can remember there being seawall there.

The seawalls were put up in the 1950s, during a hurricane run that gave us Edna and Carol. The seawalls allowed coastal development in an area that was devastated during the 1938 Hurricane and the 1954 sisters.

The seawalls suffer from cracks, crumbling, collapse, erosion and other ailments. The seawall shown putting in work at bottom of the article is from this area.

The green area is where I'm from, and the seawall is just a big slab of concrete. It does the job we ask of it. The neighboring orange area was a portion of the wall (near the old Gurnet Inn) that had started to fall forward. The US Army Corps of Engineers is in charge of repairing the wall, and they dumped tons of boulders against it to arrest the Tower Of Pisa act.

The orange wall in more northern Green Harbor is much "taller" (more of it is exposed, where down-beach Duxbury gets a lot of sand washed up against it) than her sister to the south. Almost the whole length of it requires boulders be shoved against it to keep it from tipping forward. The houses are built right up to the seawall in many cases there.

The extreme top/north of the picture features two giant jetties, made out of piles of boulders, that protect Green Harbor.

Regarding the cost of seawalls, the old divorce joke works pretty well.

                                        Why do seawalls cost so much?

Because they're worth it!