Boston Harbor Flood Protection Projects

[JeffDowntown]

UMass Boston says spend $2b on neighborhood preparations, don't count on a Winthrop-Hull barrier ($11b) or Airport-Seaport ($8b)

http://www.wbur.org/news/2018/05/30/boston-harbor-barrier-flooding-umass-study

https://www.bostonglobe.com/metro/2...h-cost-effort/BdEjVDgNNucNM8gP1tlZ4O/amp.html

The UMass Boston study is pretty nieve about the legal reality of all those "neighborhood preparations". The experience in New Jersey, after Hurricane Sandy, is that pissy, NIMBY property owners all along the waterfront gum up the works of the local preparation (seawall in front of property, blocking part of the view, for example -- take the city to court). The neighborhood preparations get stalled in litigation that costs way more than the construction.

The neighborhood preparations will never get done, and are not effective if not near 100% coverage (gaps can cause widespread flooding).

 

[Equilibria]

The UMass Boston study is pretty nieve about the legal reality of all those "neighborhood preparations". The experience in New Jersey, after Hurricane Sandy, is that pissy, NIMBY property owners all along the waterfront gum up the works of the local preparation (seawall in front of property, blocking part of the view, for example -- take the city to court). The neighborhood preparations get stalled in litigation that costs way more than the construction.

The neighborhood preparations will never get done, and are not effective if not near 100% coverage (gaps can cause widespread flooding).

Those New Jersey property owners were beachfront vacation homes, though. I feel like that makes a difference. People are okay with their insured second house flooding in October.

 

[Ruairi]

30 years??
It could take 30 years to build a wall??
how in gods name could it take 30 years?

I know a question like this induces sniggers and talk of incompetence but I'm genuinely curious as to how building a 3 mile sea wall could take 30 years?

 

[CSTH]

UMass Boston says spend $2b on neighborhood preparations, don't count on a Winthrop-Hull barrier ($11b) or Airport-Seaport ($8b)

http://www.wbur.org/news/2018/05/30/boston-harbor-barrier-flooding-umass-study

https://www.bostonglobe.com/metro/2...h-cost-effort/BdEjVDgNNucNM8gP1tlZ4O/amp.html

Have not had a chance to read in depth yet, but based on the Exec Summary and a skim ...

... I think this study is deeply problematic. At best you could maybe say that they have failed to take their own assumptions seriously, and perhaps buried the real takeaway. A more hard-nosed evaluation would say that this is wishful thinking at it's worse.


Here's my emerging critique. I'll take a closer look this evening and try to update this. But for the moment...

- The study assumes 1 ft. of SLR by 2030, 3 ft. by 2070, and 5 ft. by 2100. This is based on IPCC scenarios. Whether or not you believe these are reasonable expectations, this is what the study assumes as the future. Those are dramatic changes, to say the least.

- Specifically, with 3-5 feet of SLR, you'd be looking at flooding on the waterfront on almost a daily basis, plus the frequent overtopping of the Charles River Dam and a frequent (multiple times per year) significant impairment of Logan Airport, Deer Island, the MBTA tunnels, and the downtown highways.

- However, the study assumes that a harbor barrier would not be used to mitigate tidal flooding - the gates would only close for storm surges. So there is no mitigation of tidal flooding assumed in the cost-benefit.

- The study also states that building a barrier would have a negative impact on coast ecosystems, shipping traffic, and water quality - but doesn't appear to recognize that the SLR that it assumes would also have those negative impacts anyway.

- And it doesn't consider that building a barrier creates options for further adaptation to SLR, especially in extreme scenarios, and that it could have additional infrastructure benefits. Specifically - the option of replacing a surge gate with a permanent lock system 50 years from now if SLR ends up being severe would be a pretty good options to have. And if you moved existing port infrastructure to new land created as part of the barrier, youd free up a lot of downtown land for development AND eliminate the need for other expensive work e.g. dredging, bridge work, etc.

tl;dr - if you are working from the assumption of 3ft SLR by 2070, the only reasonable recommendation is "Start working on small-scale local mitigation today, AND also get the process started for long-term investment in a piece of infrastructure that could literally be make-or-break for huge parts of the city.

 

[Joel N. Weber II]

Page 14 of https://www.dropbox.com/s/zwznes9jin41i5k/Feasibility of Harbor-wide Barriers Report.pdf?dl=0 near the bottom right corner claims they are assuming that present shipping should be preserved.

I think preserving access to Conley Terminal and Flynn Cruiseport (formerly known as Black Falcon Terminal) makes a lot of sense, but it's less clear that shipping further into the harbor is needed.

Do they really believe that gasoline deliveries to Chelsea Creek should continue? Is continuing to bring LNG to Everett a good idea in the long term future? If many of the current brands of internal combustion engine vehicles go out of business as electric vehicle manufacturing ramps up, will we continue to import completed automobiles at all, and if so, might building new roll on roll off infrastructure at Reserved Channel be cheaper than maintaining access to the current port facilities in Charlestown? Does exporting scrap metal instead of remanufacturing locally make sense? If Logan continues to need liquid fuel, can we relocate the dock where the fuel is received to get those boats out of Chelsea Creek?

I also don't understand the design assumption on page 17, where they argue that a 1500' wide opening is required for navigation. https://en.wikipedia.org/wiki/List_of_longest_ships seems to be saying that the longest ships currently afloat are 400m (1312') long. Perhaps 1500' would be sensible if ships normally came into port sideways, but ships don't normally come into port sideways. Rather than pedantically following rules that were written without thinking about the needs of a flood barrier, we ought figure out what ships we actually want to accommodate and how many of them are going to enter the harbor at a time, and think about a design that has multiple smaller openings that would successfully accommodate the actual boat traffic we expect, and get the legislators who are going to have to allocate money for this thing anyway to adjust the rules based on more flexible engineering thinking.

And what if the flood barrier had a set of locks where at mid to low tide the gates on both sides of the locks were left open? With enough openings at mid to low tide, could we get enough water flowing in and out of the harbor to maintain water quality? (The right design might be a mix of gates that would be open at mid to low tide and closed at high tide with no way for boats to get through at high tide, along with locks which would let boats through regardless of tide, functioning as locks at high tide and allowing water to flow freely at mid to low tide, since we probably need water flowing in and out at more places than we need navigable channels. Or maybe using the locks as locks at low tide could reduce water velocity at the locks at low tide to make navigation easier.)

Page 18-19 has some discussion that increases in water velocity from a barrier could make navigation by small boats much more challenging.

And it's certainly quite possible that shore based adapation may turn out to be a better approach than a big barrier even if their dubious assumptions about the big barrier are corrected.

 

[stellarfun]

The opening for ships at the storm surge barrier for Rotterfam (a much busier harbor than Boston) is a bit over a thousand feet.

https://en.wikipedia.org/wiki/Maeslantkering

 

[JeffDowntown]

I am always surprise as to how people view the harbor island flood barrier as super challenging.

But the Dutch have been constructing major storm surge barriers since the early 1930's. The various mechanisms needed for ship access (as above), tidal flushing, solid barriers, sluices, etc. are all worked out. We just need to be smart and hire engineers from The Netherlands to design the system.

There is a great website that profiles all the storm surge elements of the huge Deltaworks initiative (which includes the Rotterdam harbor gates above, called the Measlant Barrier).

http://www.deltawerken.com/English/10.html?setlanguage=en

One thing that often gets missed in the discussion of near coastal defenses rather than a harbor barrier is the physical length of the protection needed. Our coast line is geometrically complex. So the total coastal area in Massachusetts Bay is probably a couple hundred miles of coast line following all the inlets, peninsulas, etc., a lot to protect. A harbor barrier would only need to be something like 20 to 30 miles in length, depending on alignment. (The Dutch did that analysis in their conclusion to build the Deltaworks.)

 

[odurandina]

i offered a proletariat-friendly version of your post in the Globe a few days ago; even mentioning the Dutch have about a 1000 year head start.... and now we got the internet to learn about other places and stuff.

too bad we can't hire the Chinese, sell them some rocks, and let them supply the cheap crane operators....

 

[tangent]

Have you guys actually looked at the flood maps? We aren't talking about a huge flood risk in Boston that can't be dealt with by a few feet of fill in a few low areas and a few feet of sea wall and/or a small strip of elevated landscaping along a few areas which will do just fine for the next 30 or 40 years.

I would focus just on the shoreline of zone A where there is an insufficient seawall/landscaped barrier:
https://www.mass.gov/service-details/hurricane-evacuation-zones

Inundation Map: http://www.mass.gov/eopss/agencies/mema/emergencies/hurricanes/hurricane-inundation-maps.html

 

[odurandina]

Possibly if the Seawall can include a strip of land large enough to put up a row of HOTELS and a toll road....

a. The gate needs a better design. Not impossible. We continue to come up with better ideas.

b. Choose the Harbor Island model from Quincy to Winthrop that requires 1.8 miles of wall, getting a free ride over the Islands.... build the barrier wide enough to accommodate an electronic toll road and a row of hotels, with the islands remaining pristine. The land created would increase the cost, but could very well pay reduce the total costs.

c. One additional possibility is to make the harbor barrier more economical by having hydro-electric/ tidal power generation running some of the time, while maintaining the harbor as a port....

To get near there; the complexities of design, economic, planning & political challenges grow exponentially, and probably require politics like FLORIDA (to kick down the doors and just do it).

Perhaps it's time to get a 2nd opinion from those otherworldly brains at MIT and get moving on getting federal funding to begin this vital project.

 

[JeffDowntown]

Have you guys actually looked at the flood maps? We aren't talking about a huge flood risk in Boston that can't be dealt with by a few feet of fill in a few low areas and a few feet of sea wall and/or a small strip of elevated landscaping along a few areas which will do just fine for the next 30 or 40 years.

I would focus just on the shoreline of zone A where there is an insufficient seawall/landscaped barrier:
https://www.mass.gov/service-details/hurricane-evacuation-zones

Inundation Map: http://www.mass.gov/eopss/agencies/mema/emergencies/hurricanes/hurricane-inundation-maps.html

But we are not talking about designing for current hurricane risk (the maps you shared).

We are talking about the 30, 50, 100 year scenarios that combine storm surge and sea level rise. Future proofing the city to survive. Like these maps. Not exactly just a few low-lying areas affected.

http://seachange.sasaki.com/

We talking about protection to prevent the flooding of most of the Seaport and East Boston, all of Back Bay, South End, Fenway, and MIT/Kendall/East Cambridge... Economic devastation. And that is just for 2050, 30 years away.

 

[CSTH]

But we are not talking about designing for current hurricane risk (the maps you shared).

We are talking about the 30, 50, 100 year scenarios that combine storm surge and sea level rise. Future proofing the city to survive. Like these maps. Not exactly just a few low-lying areas affected.

http://seachange.sasaki.com/

We talking about protection to prevent the flooding of most of the Seaport and East Boston, all of Back Bay, South End, Fenway, and MIT/Kendall/East Cambridge... Economic devastation. And that is just for 2050, 30 years away.

Exactly. This isn't optional.

I frankly can't understand how and why the study screwed up as badly as it did.

It's as if I asked, "There's going to be an intense Nor'easter next week, and I need to stay warm and dry on my walk to work...what should I wear on top of my business casual: a pair of gloves, or a cotton sweatshirt?"

And this study answered: "A cotton sweatshirt will not keep you warm after it gets wet, so don't waste your money on that - just go with the gloves".

(The right answer, of course, is to ask a better question...Should I get a parka and a hat, as well as wool sweater and gloves? And take the T to work instead of walking? Or maybe work from home?)

Seriously: they specified a set of proposed solutions that would not adequately address the problems they anticipate, and then recommended against building them because they would not adequately address the problems they anticipate. Its impossible to know whether this is incompetence or a whitewash, but either way its a huge waste of time, energy, and public attention.



The reality is this: Sooner or later, we're going to have to turn the outer harbor into an artificial lake. Just like we did with the Charles Basin. Most of you probably know that ocean-going ships used to call as far up river as the Arsenal in Watertown. And the water west of Peninsula was just as much part of the harbor as that to the east.

So we should have the courage and vision to transform the existing harbor in the same way. Build a big dam from Deer Island to Hull, and put a couple of locks in it (and plug the weak points in Revere etc too). Keep the small ships and fuel barges moving through the lock, and relocate the container ships, LNG, auto ROROs, Coast Guard, and big cruiseliners to a new facility on Long Island. Then build new waterfront neighborhoods on Mystic pier, the CG station in the North End, and the Reserved Channel.

Call the enclosed body of water the Front Bay if you want to be corny. Or the New Harbor. Or Lake Menino. Or the New Boston Basin. Call the inner Harbor the Boston River.

The point is, we have to think that water differently than we have. Its not going to be part of the Atlantic anymore - just like the Charles Basin hasn't been for 150 years.

It's going to have to happen eventually. And if we do it right, we can get improved transportation infrastructure, new land for expanding the city, and extraordinary public spaces and recreational amenities at the same time, in addition to a critical piece of environmental-management infrastructure. (And we will also be able to forgo the expected costs of dredging the reserved channel, re-building the Long Island Bridge, etc. in the process.)

It's a shame that this study made all of that a little harder to get to.

 

[odurandina]

^^This.

Seems somebody agrees with you about this sham of a study....

https://www.bostonglobe.com/opinion...worth-money/pr6SK7KqmTVn68c4ctO2UM/story.html

Time for a sober discussion about how you fortify $500B of property from the North Atlantic.

 

[Ruairi]

Exactly. This isn't optional.

I frankly can't understand how and why the study screwed up as badly as it did.

It's as if I asked, "There's going to be an intense Nor'easter next week, and I need to stay warm and dry on my walk to work...what should I wear on top of my business casual: a pair of gloves, or a cotton sweatshirt?"

And this study answered: "A cotton sweatshirt will not keep you warm after it gets wet, so don't waste your money on that - just go with the gloves".

(The right answer, of course, is to ask a better question...Should I get a parka and a hat, as well as wool sweater and gloves? And take the T to work instead of walking? Or maybe work from home?)

Seriously: they specified a set of proposed solutions that would not adequately address the problems they anticipate, and then recommended against building them because they would not adequately address the problems they anticipate. Its impossible to know whether this is incompetence or a whitewash, but either way its a huge waste of time, energy, and public attention.



The reality is this: Sooner or later, we're going to have to turn the outer harbor into an artificial lake. Just like we did with the Charles Basin. Most of you probably know that ocean-going ships used to call as far up river as the Arsenal in Watertown. And the water west of Peninsula was just as much part of the harbor as that to the east.

So we should have the courage and vision to transform the existing harbor in the same way. Build a big dam from Deer Island to Hull, and put a couple of locks in it (and plug the weak points in Revere etc too). Keep the small ships and fuel barges moving through the lock, and relocate the container ships, LNG, auto ROROs, Coast Guard, and big cruiseliners to a new facility on Long Island. Then build new waterfront neighborhoods on Mystic pier, the CG station in the North End, and the Reserved Channel.

Call the enclosed body of water the Front Bay if you want to be corny. Or the New Harbor. Or Lake Menino. Or the New Boston Basin. Call the inner Harbor the Boston River.

The point is, we have to think that water differently than we have. Its not going to be part of the Atlantic anymore - just like the Charles Basin hasn't been for 150 years.

It's going to have to happen eventually. And if we do it right, we can get improved transportation infrastructure, new land for expanding the city, and extraordinary public spaces and recreational amenities at the same time, in addition to a critical piece of environmental-management infrastructure. (And we will also be able to forgo the expected costs of dredging the reserved channel, re-building the Long Island Bridge, etc. in the process.)

It's a shame that this study made all of that a little harder to get to.

Excellent post, and the bulk of this needs to be done by 2030.

 

[tangent]

But we are not talking about designing for current hurricane risk (the maps you shared).

We are talking about the 30, 50, 100 year scenarios that combine storm surge and sea level rise. Future proofing the city to survive. Like these maps. Not exactly just a few low-lying areas affected.

http://seachange.sasaki.com/

We talking about protection to prevent the flooding of most of the Seaport and East Boston, all of Back Bay, South End, Fenway, and MIT/Kendall/East Cambridge... Economic devastation. And that is just for 2050, 30 years away.

The maps are based primarily on elevation above sea level... which was the point of referencing them to identify those areas that are at risk due to sea level rise and storms surge.

The bottom line is that you can't rely on a sea barrier out at he mouth of the harbor for anything other than storm surge. You can't block off the mouth of the river very long because you have water flowing in behind it and it will fill up and cause flooding. If you want to effectively address 3 to 5 feet of sea level rise at every tide then you need to raise up the coast line at least 3 to 5 feet where that sort of surge or sea level rise would cause flooding like we saw this year or worse.

And if you leave areas just behind the coast line below sea level then you are going to be relying on pumps and levies rather than gravity to keep them from flooding. Pumps and levies are the very things that are prone to failure in a category 4/5 storm, tsunami, or the major earthquake we are over due for.

The UMass study wasn't completely discounting the idea of a Boston Harbor barrier. But it would certainly be better to focus on the shoreline and lowland area mitigations in the medium to nearer term. The cost benefit is much clearer.

 

[JeffDowntown]

The maps are based primarily on elevation above sea level... which was the point of referencing them to identify those areas that are at risk due to sea level rise and storms surge.

The bottom line is that you can't rely on a sea barrier out at he mouth of the harbor for anything other than storm surge. You can't block off the mouth of the river very long because you have water flowing in behind it and it will fill up and cause flooding. If you want to effectively address 3 to 5 feet of sea level rise at every tide then you need to raise up the coast line at least 3 to 5 feet where that sort of surge or seal level rise would cause flooding like we saw this year or worse.

And if you leave areas just behind the coast line below sea level then you are going to be relying on pumps and levies rather than gravity to keep them from flooding. Pumps and levies are the very things that are prone to failure in a category 4/5 storm, tsunami, or the major earthquake we are over due for.

The UMass study wasn't completely discounting the idea of a Boston Harbor barrier. But it would certainly be better to focus on the shoreline and lowland area mitigations in the medium to nearer term. The cost benefit is much clearer.

The harbor barrier is a long term insurance policy.

Most people never collect long term insurance, like a homeowners insurance policy. In the broadest context insurance always fails a simple cost benefit analysis.

But you cannot insure your home after it is destroyed in a flood. You can only insure it before the event.

 

[tangent]

The harbor barrier is a long term insurance policy.

Most people never collect long term insurance, like a homeowners insurance policy. In the broadest context insurance always fails a simple cost benefit analysis.

But you cannot insure your home after it is destroyed in a flood. You can only insure it before the event.

I'd rather the less expensive insurance which has more benefits than the more expensive policy that will likely never pay off and only covers one scenario.

The flood barrier isn't a replacement for shoreline protection and raising elevations in some areas prone to flooding. You need to do those things either way. The flood barrier protects against Cat 4/5 storm surge and is itself prone to catastrophic failure and the need for expensive maintenance over the decades during which it would likely never be of need. The chances of it being politically/economically supportable over the next 50 years are very unlikely. I would actually look to spec it out as a 20-30 ft tsunami barrier if you want to get bang for your buck.

 

[stellarfun]

Tide gauges at 98 coastal locations in the U.S. indicated flooding on a record-breaking six days on average, the report said. More than a quarter of these gauges tied or broke previous records for the number of days with flooding.

Topping the list of locations that set high-tide flooding records were Boston and Atlantic City, which flooded on 22 days, and Sabine Pass and Galveston, Tex., which flooded on 23 and 18 days, respectively.
.......
NOAA’s February report on high-tide flooding made even more dramatic projections for the middle and latter parts of this century, when high-tide flooding could occur every other day in many coastal locations.

https://www.washingtonpost.com/news...level-rise-and-storms/?utm_term=.e2e73168b658

 

[CSTH]

The maps are based primarily on elevation above sea level... which was the point of referencing them to identify those areas that are at risk due to sea level rise and storms surge.

The bottom line is that you can't rely on a sea barrier out at he mouth of the harbor for anything other than storm surge. You can't block off the mouth of the river very long because you have water flowing in behind it and it will fill up and cause flooding. If you want to effectively address 3 to 5 feet of sea level rise at every tide then you need to raise up the coast line at least 3 to 5 feet where that sort of surge or sea level rise would cause flooding like we saw this year or worse.

And if you leave areas just behind the coast line below sea level then you are going to be relying on pumps and levies rather than gravity to keep them from flooding. Pumps and levies are the very things that are prone to failure in a category 4/5 storm, tsunami, or the major earthquake we are over due for.

The UMass study wasn't completely discounting the idea of a Boston Harbor barrier. But it would certainly be better to focus on the shoreline and lowland area mitigations in the medium to nearer term. The cost benefit is much clearer.

The charles and Mystic rivers are ... already blocked by dams. There’s just not that much volume to deal with. We’re not talking about the Rhine here.

Yes, you’ll be pumping water out of the basin and into the ocean. We’ve been doing that with the Charles River for 40 years.

So yes, actually, we could rely on a harbor barrier for both SLR and storm surge.

Parts of holland have been below sea level for centuries. Are there risks? Of course. But there are also not a lot of alternatives.

 

[stellarfun]

Another study.

The near term forecast is less daunting, but should still serve as a wakeup call. In 2030, the study points to 3,303 properties as facing chronic flooding, with a combined value of $2 billion.

Revere is the municipality with the greatest number of homes at risk (573), followed by Hull (491), Salisbury (457), Quincy (354) and Winthrop (200). Some 6,500 people live in these “at-risk” homes, according to the study [by Union of Concerned Scientists].

http://www.wbur.org/news/2018/06/18/sea-level-rise-massachusetts-homes