Hendrick’s Folly : Old Guilford Avenue Diversion Tunnel

In Urban Exploration - Drains/Sewers by Ronnie K0 Comments

Jones Falls Conduit Old tunnel

After leaving the Goliath Chamber : Junction Chamber II , the explorer enters into an ancient like vestibule, only seen by few.  A passage into another outset, a unseen threshold of buried time . It is as symbolic as it is literal. Because at this point of the journey, you have crossed into the original, old Guilford Avenue Diversion Tunnel.

Upon entering Hendricks Folly, the air quality almost immediately changes. Almost like 2 distinct different atmospheres or gradients. Pockets of old, un-circulated air back in there. The explorer would push forward with much caution, as the air becomes thick, heavy and humidity laden. The explorer is concerned about this. It is assessed to be old air, stagnant air. The explorer continues to carefully assess the conditions. The mission could be aborted at any time. The density of the air in this section is evident when using flash photography.
jf conduit old hendricksProceeding forward, the tunnel landscape takes a drastic change. The floor is convex and brick laden, laid hundreds of years ago. For the first time, the explorer is one with the river. They walk in the river and not separate from it like the previous sections. The brick floor, is extremely slippery and the explorer ends up embracing the river, walking straight down the center. There is too much risk and energy expended by attempting to creep the sides of the sewer. The explorer finds that convex shape of the floor coupled with the ultra slick surface is difficult to remain up right. Water is leaking from the ceilings but the drops go unheard over the resonance of the rivers hum.



“The heading of the tunnel,under Guilford avenue, has been extended from the entrance of the retaining wall between Biddle and Chase streets to a point 25o feet beyond Preston street a total distance of 8oo feet” (ref. 1)

Jones Falls Conduit tunnel 3

JF Conduit

Approximately 100 meters deep inside this section, there is a massive storm drain outfall that draining a number of large buried streams into the diversion tunnel. It is always pushing out a high volume of air. A drain within a drain. The internal outfall tube is concrete with a brick laden bottom . After some research, it is concluded that this is “Jenkins Run”. Which means this massive tunnel leads into another network of century old storm sewers. In fact, as of 1909, it was draining 900 acres of area. Another excerpt from the Sewerage Commission of Baltimore City Report dated 1912 page 12 states:

“The heading of the Jenkins tunnel has been extended through to meet the large tunnel a distance of 430 feet The rock excavated from this tunnel is being crushed and used to form the concrete conduits in the bed of the Falls below Preston street”.

Jenkins Run Storm Sewer – AVOID remains with us and reminds us of the ideal plan of action.

10 foot outfall storm sewer

approaching jenkins run

Approaching the Outfall of Jenkins Run (left side) heading south.
As soon as the explorer navigates past this massive outflow,  a strong wind is pressing on their back. Again, this is a comfort to the explorer. In contrast with the previous stagnant air pocket, this fast moving stream of air enables further penetration.  Travel past this point continues to prove slow and strenuous. The sides of the tunnel remain convexed and angled upward. What feels like an eternity, the tunnel continues straight forward. Eventually, a slight bearing to the left is noted which obscures an possibility to assess what lies ahead. The tunnel wind begins to fade. After some time, the distant sound of rushing water is heard. The explorer is apprehensive in what lies ahead as the LED’s of the explorers lamps are only piercing the darkness so far. The tunnel finally straightens out again. The explorer finds themselves in the precursors of the Original Jones Falls Conduit…Jonesy’s Last and Final Run.

Jones Falls Conduit System
Jones Falls River Infall Stage
JFX Intake/Infall Tunnels
JFX Triple Barrel Junction Chamber
JFX Diversion Tunnels
Guilford Avenue Junction Chamber
Old Guilford Avenue Diversion Tunnel
The Original JF Conduits Proper


(ref.1) Annual Report of the Sewerage Commission of Baltimore City, 1913 , page 12

Many of the environments & areas presented on this website are hazardous, and were only entered on the basis of extensive training, experience and planning. Do not try to access these sites / tunnels / storm sewers , they should not be trifled with.   The intent of these pages are to provide historical documentation.  An explorer already risked their life, so that you can explore virtually from home… so stay safe, and stay away! Consider this neither a disclaimer, nor a recommendation.

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