Start Of North Tunnel Construction Project Prompts Closure Of Parking Lot

ELLICOTT CITY, MD — Starting Monday, parking lot B in historic Ellicott City will close so that construction on the north tunnel located near the parking lot can proceed.

The lot will close at 6 a.m. April 28. Signs will be posted in the area to alert residents and drivers of the closure. Construction work will be done weekdays from 7 a.m. to 3:30 p.m.

To accommodate for the temporary closure of parking lot B, the county will be lifting the two-hour parking restrictions along Maryland Avenue until the project wraps up sometime in mid-2027, officials said.

The north tunnel is part of the Ellicott City Safe and Sound Plan. In June 2025, officials broke ground on the Ellicott City Safe and Sound North Tunnel project. As voted on by the community, the tunnel boring machine was named Rocky.

Once complete, the 18-foot diameter, approximately one-mile-long subterranean North Tunnel will have the ability to move 26,000 gallons of water per second from the west end of Ellicott City all the way to the Patapsco River. The tunnel will reduce the risk of flash flooding by intercepting water and diverting it underground and away from Main Street.

The work will be executed primarily using a tunnel boring machine that is roughly 300 feet in length and can carve through solid granite. The TBM will be overseen by a joint venture between Kiewit and Traylor Bros., Inc. experts in the tunnel excavation field.

The extended North Tunnel is one of seven flood mitigation projects in the EC Safe and Sound Plan. Officials broke ground earlier this month on the third and largest stormwater retention pond in Ellicott City's Safe and Sound plan. The H4 dry flood mitigation pond should be completed by late September 2025. It will hold up to 5.5 million gallons, the equivalent of a football field that's 12.8 feet deep, which would otherwise flow directly into the Tiber-Hudson River and down to Main Street. The pond will be constructed along the north side of Frederick Road just west of US 29.