The history of hidden hydrology isn’t just that of erasure, but of ‘made land’, significant areas that were added to cities through the process of landfilling. A June, 2017 post from National Geographic’s All Over the Map blog captures this on the east coast, telling the story of “How Boston Made Itself Bigger” illustrated with some fantastic maps.  The focal map shows the extent of landfilling throughout the span from 1630 to present, from the original shape of the downtown area (Shawmut Pennisula), and the modern shoreline in blue.  The massive extent of fill is pretty evident with significant percentage of the metro area on land that at one point in the not-so-distant past was water.

Much of Boston’s coastline is man-made land. The original shoreline, from 1630, is visible in dark green on this map. Land made between 1630 and 1995 is light green. PHOTOGRAPH COURTESY OF THE NORMAN B. LEVENTHAL MAP CENTER, BOSTON PUBLIC LIBRARY; CARTOGRAPHY BY HERB HEIDT AND ELIZA MCCLENNEN, MAPWORKS

A 1630’s map shows the Shawmut, and the narrow spit of land that connected this (for a time at least) to the mainland (rotated north to the right).


The impetus for the post on Boston was driven by lowering of the water table to levels that started to potentially reveal many of the wood piles, which stay preserved in anerobic conditions – as similar situation to a water-based city like Venice, for instance, but once water levels reveal them, makes them highly susceptible to rot.  From All Over the Map:

” A large portion of the city sits on man-made land. Structures built on the landfill are supported by dozens of 30- to 40-foot-long wood pilings, similar to telephone poles, that reach down through the landfill to a harder layer of clay. These pilings sit entirely below the water table, which protects them from microbes that would attack them in dry air, causing rot.”

The filling also was facilitated by damming, such as seen below, where what was the current Back Bay “neighborhood is marked “Receiving Basin” on this map. Boston Common is the uncolored area marked “Common.”  By damming the areas, thus separating them from the larger bodies of water and tidal changes, it was easier to then start to develop and fill in with railroads, industrial lands and more development.  The image shows expansion parcels, notably widening of the neck and further encroachment into the water.


As mentioned, it wasn’t just increased development area that was driving the land filling:  “Over the years there were many other motivations for making new land, including making harbor improvements, burying pollution from wastewater, safeguarding public health, building public parks, adding railroad tracks and depots, adding more shipping facilities to compete with other port cities, establishing appealing neighborhoods to entice Yankees to stay (and to counter Irish immigration), and creating space for the city’s airport.”  Another driver was public health, including filling in ponds and creeks, which were starting to smell.  Concurrent with filling (and a great source of fill) was removal of hillsides, another common city strategy, which provided plenty of earth to create more land while levelling, in this case, Beacon Hill. (via Wikipedia)

Cutting down Beacon Hill in 1811; a view from the north toward the Massachusetts State House

The Back Bay was a source of both significant filling due to its location as a locus of sewage (and a super complicated hydrological regime change that was involved), as mentioned in All Over the Map“…an 1849 report from a city committee that reads: “Back Bay at this hour is nothing less than a great cesspool into which is daily deposited all the filth of a large and constantly increasing population … A greenish scum, many yards wide, stretches along the shores of the Western Avenue [Mill Dam], whilst the surface of the water beyond is seen bubbling like a cauldron with the noxious gases that are exploding from the corrupting mass below.”  The area was filled with trash and other debris, as fill material was less available, along with being set on the aforementioned pilings, placing it in the awkward position of being even now “one of the city’s most desirable neighborhoods, but also among the most vulnerable to foundation rot.”

I’d be remiss as well if I didn’t mention, in the context of this, one of my favorite Olmsted projects, the Back Bay Fens, which came at the tail end of the filling, in the 1870s (via Wikipedia):  “Olmsted’s challenge was to restore the spot of marsh which was preserved into an ecologically healthy place that could also be enjoyed as a recreation area. Combining his renowned landscaping talents with state-of-the-art sanitary engineering, he turned a foul-smelling tidal creek and swamp into “scenery of a winding, brackish creek, within wooded banks; gaining interest from the meandering course of the water.”

The extent of land filling is hard to visualize, but the map that shows it most clearly in terms of downtown is a simple overlay of the original Shawmut Pennisula over the new shoreline (you can see the tip of the Back Bay Fens in the lower left hand corner).

Via Written in Stone…

And while not the most up-to-date map in terms of graphic style, a good way to illustrate the evolution of landfilling over time that is hard to capture on maps is this animation via the Boston: History of the Landfills page at Boston College.   Someone has probably updated this, so if you know of it, let me know any updated sources.

A later map in 1867 from the NOAA US Coast Survey below shows further expansions closer to the modern coast.  Although the land and coast changed less in the ensuing century and a half, the continuing legacy of the land filling continues to be costly to maintain, exacerbated especially in times of changing water levels that we are experiencing with global climate change.

The hydrology as well, although hidden, is evident in repairs for pilings and other issues of groundwater – a symptom of building and ‘making land’ on areas formally water. And as concluded in All Over the Map, “…with more than 5,000 acres of man-made land—more than any other American city (except perhaps San Francisco, where the landfill hasn’t been comprehensively totaled)—Bostonians will be living with this problem for the foreseeable future.”


Plenty of folks have covered this in Boston and the idea of land filling, with a variety of maps and imagery, such a Boston Geology, and some more context on the pilings from the Boston Groundwater Trust.  Also, this great post from the Library of Congress ‘Putting Boston on the Map: Land Reclamation and the Growth of a City’ features a few maps, including one of the earliest maps, which highlights the former tight pennisula.

William Burgis and Thomas Johnston. “To his excellency William Burnet, esqr., this plan of Boston in New England is humbly dedicated by his excellencys most obedient and humble servant Will Burgiss.” 1728. Geography & Map Division, Library of Congress.

And a fabulous birdseye from the late 1800’s showing more significant filling.

Charles R. Parsons and Lyman W. Atwater. “The city of Boston.” 1873. Geography & Map Division, Library of Congress.

See the some of the timeline of history via the USGS series of maps of Boston here, or a more interactive map via MapJunction with an array of base and historical map overlays of Boston, including a cool 4-way slider that allows you to do an overlay left-to-right and control transparency top-to-bottom.  A couple of screen shots of these.

1776 Hybrid Map (Boston and Environs – Pelham)
1917 Hybrid Map (Boston Bromley Atlas)

And an out-of-print book worth tracking down is Nancy S. Seasholes Gaining Ground: A History of Landmaking in Boston (MIT Press, 2003) where the “story of landmaking in Boston is presented geographically; each chapter traces landmaking in a different part of the city from its first permanent settlement to the present.” 

Many cities share this trait, using fill to gain area, which has been both boon and boondoggle.  Locally, a great resource worthy of a deep dive is Too High and Too Steep: Reshaping Seattle’s Topography by David B. Williams (University of Washington press, 2015), which I’ve read and re-read which explores in detail, a similar massive manipulation and use of made land here in my current particular West coast City.

HEADER:  Image via National Geographic, “A map of Boston in 1775 shows the dam that closed off Mill Pond, which was later filled in to make new land. “  PHOTOGRAPH COURTESY OF LIBRARY OF CONGRESS


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