1 vote

Seneca Aqueduct


Historic American Buildings Survey John O. Brostrup, Photographer September 16, 1936 11:35 A. M. View Of Aqueduct From Southeast

Photo taken for the Historic American Buildings Survey

View photos at Library of Congress

BH Photo #222653

Street View 


Canal engineers build aqueducts to bridge canal boats over rivers and large stream such as Seneca Creek. Eleven aqueducts were needed between here and the canal’s western terminus at Cumberland, Maryland; all required skilled quarrymen and stonemasons, and large outlays of scarce capital.

Seneca Aqueduct opened to traffic in 1833, and along with through-boats from the west, carried a substantial local traffic in lime, grain, fertilizer and sandstone to and from farms and industries around Seneca. Made of red sandstone from nearby bluffs, it has long been one of the most admired canal structures.

Freshets and flooding on Seneca Creek have always caused problems, and finally in September, 1971, almost 50 years after the canal closed, a violent local flood swept away one of the arches.

The last locktender at Seneca was Johnny Riley, whose former lock and lockhouse are at the east end of the aqueduct. “I don’t care what hour of the night it was,” recalled a former boatman, “any hour of the night you boat to his lock and holler . . . there was his lantern waving you ahead.”


Brick arch bridge over Seneca Creek on C&O Canal Path
Montgomery County, Maryland
Open to pedestrians
Built 1833, One span collasped after flooding in 1971
Brick arch
Eligible for the National Register of Historic Places
Approximate latitude, longitude
+39.06867, -77.34101   (decimal degrees)
39°04'07" N, 77°20'28" W   (degrees°minutes'seconds")
Approximate UTM coordinates
18/297472/4327005 (zone/easting/northing)
Quadrangle map:
Inventory number
BH 50768 (Bridgehunter.com ID)

Update Log 

  • November 1, 2016: New Street View added by Dana and Kay Klein
  • July 9, 2014: New photos from Andrew Raker
  • April 22, 2013: Updated by Craig Philpott: added engineer
  • January 7, 2012: New photos from Daniel McFarland
  • January 2, 2012: Updated by J.P.: Added category "HAER documented"


  • J.P. - wildcatjon2000 [at] gmail [dot] com
  • HABS MD-57-B - Chesapeake & Ohio Canal, Aqueduct No. 1, Riley's Lock Road Vicinity, State Route 190, Seneca, Montgomery County, MD
  • Daniel McFarland
  • Craig Philpott - craigphilpott63 [at] gmail [dot] com
  • Andrew Raker
  • Dana and Kay Klein