Att02_Drawings_Dam_5.pdf

This is a set of schematic construction drawings for the repair of Potomac River Dam 5 located at C&O Canal National Historical Park in Maryland, prepared by the National Park Service Denver Service Center. The project (PMIS No. 326202) addresses deterioration of the historic run-of-river masonry dam through comprehensive repairs including removal and replacement of the existing concrete cap, repointing and grouting of masonry voids and cracks, installation of vertical rock anchors, tremie concrete placement, erosion control, and site revegetation.

The work scope encompasses repair of the downstream dam face, foundation stabilization through underwater void filling, and installation of grouted anchors at 8-foot spacing along the dam crest. The contractor must design and submit detailed plans covering water diversion structures, excavation and backfill procedures, anchor installation, concrete cap replacement, and construction sequencing. Key constraints include maximum 15 mph speed limits on the towpath with 15-ton vehicle weight restrictions, floodplain operations requiring flood monitoring and mitigation plans, time-of-year restrictions on in-stream work (March 1 through June 15 per Maryland Department of Environment requirements), and tree protection protocols for vegetation greater than 3 inches diameter at breast height. The contractor must obtain a valid license in Maryland and West Virginia, coordinate with NPS on staging and laydown areas, and comply with all state and federal environmental permits including NPDES stormwater, waterway and wetland authorizations, and dam safety requirements. Construction access involves upgrades to existing roads and boat launch facilities, with temporary structures to be removed and sites restored upon project completion.