Monocacy Aqueduct


US Department of the Interior, National Park Service


Dickerson, Maryland

Key Challenges & Project Details

  • Stabilize the historic C & O Canal Stone Arch Aqueduct over the Monocacy River, originally constructed in 1833
  • Work included stone masonry repairs to the aqueduct using specialized cementitous pressurized grouting stabilization methods
  • Scour repair
  • Removed temporary bracing system
  • Removed prism fill and restored prism walls
  • Poured structural slab and decorative topping slab
  • Removed and replaced coping stones
  • Replaced mule rail and ornamental fencing
  • With JMT, Corman overcame grouting issues by re-designing a new grouting method involving removal of the arch fill (in sequence) and replacement with a tie rod system and flowable fill
  • Corman’s new grouting method was completed in 6 months at no extra cost to the National Park Service and afforded clear evidence of structural stability
  • Pedestrian traffic was maintained on the structure during the entire project

Design Partner

Johnson, Mirmiran and Thompson (JMT)