Image credit: “Theodore Roosevelt Island Swamp” by Mr.TinDC via Flickr. Licensed under CC BY-ND 2.0.

Summers in Washington are often described as swamp-like, and politicians frequently promise to drain the swamp. Plus, with the way mosquitoes swarm the city, it certainly feels like a swamp. These common topics of discussion are all based on the long-held belief that our capital city was built on a swamp. But how much truth is there to that notion?

Was Washington, DC built on a swamp?

Contrary to popular belief, Washington was not built on a swamp. It’s a myth that has become ubiquitous among locals and tourists alike, but history doesn’t back it up. Here’s what you should know about the origins of our nation’s capital.

Debunking the myth that Washington DC was built on a swamp

The Landscape of Washington, D.C.

Unlike cities such as New Orleans and Chicago which were actually built on swamps, Washington was built on a riverbank. According to a National Park Service Ranger, the capital city is in a coastal floodplain, so it can be affected by tides, which occasionally make the ground soft and moist. In addition, parts of the city, like the National Mall, were built on low points in tidal flats near the Potomac River, the Anacostia River, and Tiber Creek. However, the majority of the city—about 98 percent—is not swampy at all.

How Our Founding Father Chose the Site for the Capital

Another common myth is that George Washington chose the location for the capital simply because he wanted it to be close to his Mount Vernon home, regardless of the climate. This isn’t true either.

It was actually a very strategic decision on the part of George Washington. He wanted the capital to be near the Potomac River and the important port city, Georgetown. He also wanted it to be far enough away from the actual swamp land surrounding the Chesapeake Bay.

So, the firm, dry riverbank of the Potomac became the site of our capital. When the plans for the city were drawn up by Pierre L’Enfant, the highest points were designated to be the White House and Capitol Hill. These focal points, along with many of the other monuments and buildings built during the 19th century, were planted on a strong foundation, allowing them to remain standing to this day.

Levees Surrounding the National Mall

In the 1800s, the National Mall was in fact prone to flooding during heavy rains, creating pond-sized puddles throughout the area and causing mosquitoes to breed there. The Washington City Canal also became clogged, exacerbating this problem. So, the Army Corps of Engineers drastically changed the landscape to create the Reflecting Pool, Tidal Basin, and beautiful parkland. Now, discreet levees protect the Mall from flooding.

Swampy Areas in Washington, D.C.

According to urban historian Don Hawkins, there are a few spots in the city that may have contributed to the swamp myth. Hawkins explains that the following areas actually were swampy in the 1970s:

  • The base of Capitol Hill occasionally flooded, and eventually the Reflecting Pool was built there
  • The Swampoodle neighborhood used to have poor drainage conditions
  • The area that is now Le Droit Park was sometimes flooded
  • The Florida Avenue sewer effluent lingered in the Anacostia River
  • Streams saturated areas near S Street in Northwest
  • Tiber Creek was turned into a sewer which flowed into the Potomac

Even though Washington may not have been built on a swamp, that doesn’t mean we are immune to swamp-like conditions in the summer, including humidity, heat, and mosquitoes! If you have pest problems in your neighborhood, contact DC Mosquito Squad today.

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