Jenkins Run Drain

In Urban Exploration - Drains/Sewers by Ronnie K

Jenkins Run Stream is an old practically forgotten underground urban stream, covered over and buried in culvert, over a period of 30 years. Now Jenkins Run Storm sewer is responsible for draining Jenkins Run Stream, Carter Alley Stream and a large impermeable area, with many small lateral drains. A a remarkable interceptor, with a robust history that is not even touched in this writing. It is responsible for draining 2 streams (ref .). Ducks under a railway and serves its tunnel’s drainage. Traverses under the graves laid in cemetery. It is quite well preserved. Stepping into here is like stepping into time portal into the early 1900’s sewer works. An excellent preservation of the past. The upper portions being constructed in the 1880’s, more work put into it after violent flooding and shotty worksmanship in the 1890’s. The lower interceptor section,is the final re-engineering of the stream leading to its dark underground outfall was finished near 1912, during the city’s drain laying Gymboree. This is when CSO / SSO #72 was placed. It boasts a significant steep grade, staircase / drop falls, full brick tunnels, brick arch horseshoe tunnels, masonry granite, overhead flume, long curves, numerous stone granite side drains and a CSO/SSO purge discharge point. In the upper mid section of the tunnel, houses a sizable double junction chamber. The western tunnel is old granite stone construction drain, that doesn’t work well. Standing water and old air back in there . The eastern shaft is the continuation of Jenkins Run. Basically, the further you go back, the older is gets. And the Jenkins Side goes back deep.

Jenkins’s Outfall
10 foot outfall storm sewer

Exploring a massive 12 foot drain, from within another massive drain requires knowledge, planning, physical fitness and wit. Such a treacherous adventure should not be carried out by a casual urban explorer, the ill prepared or weak hands.  When this drain was discovered, research seemed to point that this tunnel was draining what was once known as “Jenkins Run”.  An ancient stream that was buried & covered over well over a century ago and is the largest buried stream outfall in the Jones Falls Conduit system. Every time this tunnel was passed, a strong curiosity beckoned for its penetration.  What lies inside was an unknown, granted its overall large size, one could only assume it was the beginning of a large storm sewer network.  If subsequent research was on point, it seemed that sizable chambers may lay within. Years later, infiltration was undertaken and the curiosity laced with patience & preparation paid off.

“The Jenkins Run Drain empties into Jonesy between Preston and Hoffman streets runs northerly via Carter alley to a point 135 feet north of Lafayette avenue and thence northeasterly to a point in Boone street north of Twentieth street For 3,270 feet to a point in Walcott street it has cross sections of from 163 to 49 square feet and is built with a segmental arch Above this it is circular and 10 feet 6 inches in diameter It drains nearly 900 acres including Homestead and that part of Waverly east of the York Road It has two principal branches

  1. In Hoffman street to Home wood avenue 4 feet in diameter
  2. In Girard avenue to Barclay street 3 feet in diameter .”

(ref. 1)

“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 250 feet beyond Preston street a total distance of 8oo feet The heading of the Jenkins Run Sewer 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 Chase street.”

(ref. 2)

The Buried Outfalls Entrance into the system

The tunnel briefly bears right before straitening out, most likely for hydrological considerations as it meets the underground Jones Falls river
jf conduit jenkins run sewer
Jenkins run and Carter Alley Junction Chamber

Looking up the stairway towards the later portion of it. 

The original Jenkins Run diversion chamber photo source (ref .2)

Jenkins Run Sewer


  1. Report of the Sewerage commission of the city of Baltimore , 1897
  2. Baltimore Sewerage Commission Annual Report, 1913