"As Above, So Below. As Within, So Without."

There are miles of old abandoned water tunnels directly under a lot of Alefantis's properties of interest. The picture above is of workmen in one of the tunnels circa 1900s.
First off there is a bit of background on the tunnels then there's a map outlining all the properties of interest in relation to the tunnel network. I've also included examples of some of the tunnels discovered.

 

The Washington Aqueduct

The Washington Aqueduct, managed by the U.S. Army Corps of Engineers, provides wholesale water treatment services to DC Water and its partners in Northern Virginia, Arlington County and Falls Church. - DC Water

The Origin of Washington's Water Supply ? Architect of the Capital

• Built in 1864 by Montgomery Meigs and the Army Corps of Engineers.
• The Washington Aqueduct forms the central node in DC's water infrastructure.
• Water splits into a set of parallel conduits and is gravity fed 9 miles from Great Falls, Maryland to Dalecarlia Reservoir.

1864 | Reference | Original

Precast conduit segments for the Washington Aqueduct.

• Water continues under Reservoir Road near Georgetown Reservoir and Glover Archibald Park.

• The aqueduct crosses Rock Creek Valley inside the Pennsylvania Avenue Bridge structurally supported by two 48-inch (122cm) arching water pipes.
  

  

• The conduits then begin to branch out in a network of smaller and smaller pipes that eventually connect with individual houses.

• In total 12 miles of conduit, 11 tunnels, 6 bridges, pump stations, pipelines, and 2 reservoirs were built. - National Park Service

Note that just before the aqueduct crosses Rock Creek it branches off left into Georgetown.

1864 | Reference

A close up of the Washington Aqueduct tunnels in downtown Washington. Note they pass straight through the White House.

1865 | Reference | Original1 | Original2

• In the mid-1920's a second conduit was added to increase the capacity of the system - National Park Service

The conduit is the largest structure of the water system. It stretches almost 12 miles downriver from the intake at Great Falls to the Georgetown Reservoir. The circular tube, built of brick, stone and mortar, is 9 feet in diameter. It was constructed by tunneling and by deep rock cuts. A road was built parallel to the conduit to facilitate cleaning repairs and inspections. The road was originally named Conduit Road, today it is MacArthur Boulevard.

1920s | Reference | Original1 | Original2

Route of the Washington Aqueduct conduit.

 

The Washington Aqueduct | YouTube

This short documentary talks about only 1 conduit used at a time. We only see the conduit down as far as Georgetown Reservoir.

Cities of the Underworld - Washington DC: Seat of Power | YouTube

This documentary give a good insight into the what the tunnels look like under DC.

 

 

The Washington City (Lydecker) Tunnel

 
The Washington (Lydecker) Tunnel, completed in 1901 by the Army Corps of Engineers, is up to 10 meters in diameter and runs 4 miles from Georgetown Reservoir to McMillain Reservoir. Shortly after in 1926 a second tunnel was dug beside it.

The Lydecker Tunnel Fiasco | Architect of the Capital

• Within a decade the District’s population had increased by 75% and it was clear that a larger system was necessary.
• The Army Corps of Engineers’ proposed the McMillan reservoir NE Washington
• In 1882 Major Garret Lydecker started building a 4 mile long tunnel connecting the new McMillan Reservoir (east) with the existing Georgetown Reservoir (west).
• The project was marred in corruption. Eventually Lydecker received a court-martialed for his role in the fiasco and was banished to the Rocky Mountains.

The Washington Post describes the reality: “A committee of experts went through the tunnel and found that instead of a solid lining, thousands and thousands of feet of the tunnel contained nothing more than a brick arch, with spaces between the sides and the top of the arch and the original rock large enough to drive a coach through.”

• The Army Corps of Engineers finished the tunnel by 1901

This map shows the proposed route of the Washington Tunnel.

1883 | Reference | Original

This map shows the water distribution network for Washington DC. The Washington Tunnel is the red broken line running left across the map from McMillan Reservoir. The old Washington Aqueduct conduit is also shown in solid red lines.

1900 | Reference | Original

 

A Brief History of Bloomingdale | Bloomingdale DC

The Army Corps added the McMillan Park Reservoir and the Washington City Tunnel (10 meters in diameter and 4 miles long) between 1882 and 1902.

Bryant Street pumping station Final Seminar Project | By Justin Kockritz

A second tunnel paralleling the original was completed in 1926 which allowed the Lydecker Tunnel to be periodically closed for routine maintenance without noticeably interrupting water service.

Configuration of the Bedrock Surface of the District of Columbia and Vicinity | usgs.gov

The diagram below shows a cross section of the tunnel. There are several vertical air shafts.

Original, p.31 | Reference

In the Widows Mite air shaft just north of Wyoming Avenue, near the line of Twenty-second Street, the official section shows a capping of "clay and sand 30 feet thick" underlain by 35 feet of "clay," but this is undoubtedly a mistake, as the gneiss has been revealed by many cellars in this vicinity under only a few feet of terrace gravel and sand. In the air shaft on the highest part of the ridge near the corner of Sand Thirty-fifth Streets the blueprint of the tunnel section shows 42 feet of "clay" lying on "soft rock" at a depth of 158.7 feet, but in fact the rotted bedrock out-cropping extensively in that area is overlain by very thin remnants of terrace gravel at 195 feet above sea level. Probably the clay referred to is mostly rctten rock.

 

Merging the two maps produced this.

 

Properties of Interest

 

Click here for full resolution

 

1. Alefantis

• 3334 N St NW, Washington, DC 20007
• Reference

2. Alefantis (Metro Interiors)

• 2605 P St, NW, Washington, DC 20007
• Reference
• Current business: Midtown Cleaners, Dry Cleaner / Press Associates Inc, Newspaper Publisher

3. Alefantis

• 1526 Wisconsin Ave, Nw, Washington, DC 20007
• Reference
• Current business: Little Birdies, children clothes shop. www.shoplittlebirdies.com

4. Alefantis

• 1531 33rd St, NW, Washington DC
• Reference
• Business: The Strand at Voltra

5. Alefantis

• 1536 Swann St, NW, Washington DC, 20009
• Reference

6. Alefantis

• 2022 Columbia Rd, NW, Washington DC, 20009
• Reference

7. Alefantis/Brock

• 2310 California St, NW, Washington DC, 20008
• Reference

8. Alefantis

• 455 Massachusetts Ave, NW, Washington DC, 20001
• Reference

9. Alefantis

• 3516 Rear, 11th St NW, Washington, DC 20010

10. Alefantis

• Transformer Gallery, 1404 P St, NW, Washington, DC 20005

11. Clinton

• 3067 Whitehaven St, NW, Washington DC, 20008
• Reference

12. Podesta

• 2438 Belmont Rd, NW, Washington DC, 20008
• Reference

 

The Washington (Lydecker) Tunnel - Air Shafts

These are approximated positions based on the maps.

A. S St & 35 St

• 3509 S St, NW, Washington, DC 20007

B. Widows mite Shaft

• 2215 Wyoming Ave, NW, Washington, DC 20008

C. Champain avenue Shaft

• Champlain St, NW, Washington DC, 20009

D. 13th street shaft. 200ft North of Florida Avenue

• 1300 Belmont St, NW, Washington DC, 20009

 

Harrison G. Dyar (Mole Man) 1900 - 1916

I've included Harrison Dyar to show some example of the tunnels in central Washingtpn DC. This is a tunnel we know about on P Street, NW. This tunnel is highlighted in green on the map above.

Smithsonian Bug Expert By Day; Eccentric Tunnel Digger By Night | Architect of the Capital

1510 P 21st St - Reference

804 B St Independence Avenue - Reference

 
2 newspapers refer to 2 different addresses below:

1 - 1510 P 21st Street - Greater greater Washington

2 - 1512 P 21st St - Washington Post

 
In the articles they talk about these various locations:

• 05/1917
  2115 P St, NW

Workmen found a tunnel on P Street when digging foundations for Pelham Courts Luxury Appartment block Now Hotel Palomar

Pelham Courts Apartment block/Hotel Palomar 2121 P St, NW

while working on the foundation for the luxurious Pelham Courts apartments in Dupont Circle, workers made an unusual discovery: "Workmen find tunnel The passage is more than 100 feet long. (Washington Post, 5/19/1917)"
So do the tunnels themselves, which fan out as far as 200 feet behind his old Dupont Circle home, though they're now sealed with concrete.
The Pelham Courts of Dupont Circle are long gone, and the property now houses the Hotel Palomar. Reference

• 09/1924
  Tunnel appeared Behind Pelham Courts

“Washington was alive with stories of mystery, intrigue, romance, and adventure.” (Post, 3/4/1942)
While driving behind Pelham Courts in mid-September of 1924, a truck’s tires sank into the ground, revealing the entrance to a hidden underground shaft. Reference

 

Summary

I conclude from my research there are many tunnels under Washington DC. The ones outlined above are ones we know about. Some are as old as 1850s. As demand for water increased they built new tunnels and laid new pipes. The older tunnels being left to decay.
Interestingly here are 4 properties that sit directly on top of the old aqueduct tunnels. Most of the properties in Washington sit above some form of a tunnel or another but it seemed quite a coincidence that the only map I could find of the aqueduct system of tunnels was from 1900s and Alefanis etc have properties either very close or right on top of them. The articles point out the tunnels aren't that far from the surface so digging down from any building wouldn't be a great challenge. You would just need to know where to dig.