CHOH 326202 Repair Historic Potomac River Dams 4 a

The National Park Service is seeking market‑research responses for a design‑build contract to repair historic masonry dams 4 and 5 on the Potomac River within the C&O Canal National Historical Park. The effort will replace deteriorated concrete caps, install rock anchors, reconstruct masonry, replace sluice‑gate hardware, add an eel‑ladder habitat feature, and provide extensive environmental protection and historic‑preservation measures. The contractor must hold licenses in Maryland and West Virginia, demonstrate prior heavy‑civil construction experience, and be able to manage complex permitting, SWPPP, and quality‑control requirements. • Demolition of existing cap, masonry, timber cribs, and steel gates; installation of a new reinforced concrete cap (≥ 4000 psi) and rock‑anchor system. • Construction of a secant‑pile wall, toe‑drain replacement, eel‑ladder habitat, and new stainless‑steel sluice‑gate assembly with associated instrumentation. • Full environmental compliance (MDE, USACE, USFWS, EPA) including SWPPP, SPCC, seasonal in‑stream work restrictions, and historic‑preservation (NHPA §106) documentation.