Ball kicks off stormwater project in historic Ellicott City in response to devastating floods

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Howard County Executive Calvin Ball Monday broke ground on his Ellicott City Safe and Sound plan’s North Tunnel stormwater conveyance project, the largest public works project in Howard County’s history.

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 area 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 (TBM) 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. 

Also, as is tradition and good luck to name a TBM, much like a sailing vessel, Ball hosted a naming campaign for Howard County’s TBM earlier this year, polling the public to choose from the following six names: Ellicott Drills, Ellicott Excavator, Granite, Granite Grinder, Hudson and Rocky. During today’s event, Ball announced that the public has spoken and with nearly 800 votes cast in total, the winning TBM name is “Rocky.” 

Weather permitting, Rocky is expected to have the North Tunnel excavated and substantially completed by fall 2027. 

Shortly after taking office in December of 2018, Ball unveiled his Ellicott City Safe and Sound flood mitigation plan designed to provide a comprehensive solution for flood control in historic Ellicott City, following recent catastrophic floods in 2011, 2016 and 2018. Ball tasked his administration with identifying creative funding options that leverage strong local, state, and federal partnerships.

In addition to the North Tunnel, Ball’s plan calls for five stormwater retention ponds (H-7, Quaker Mill, H-4, NC-3 and T-1), the Maryland Avenue Culverts water conveyance project, enhanced stream inspections and debris removal following storms, an Outdoor Tone Alert System, high-ground signage and access points, and drainage improvements throughout the watershed.

To date, the H-7 and Quaker Mill ponds have been completed, enhanced stream inspections and debris removal are initiated following each storm, and the Outdoor Tone Alert System and high-ground signage and access points have been installed.

Together, the H-7 and Quaker Mill ponds have the capacity to collect and control the release of seven and a half million gallons of water during a storm. Upon the completion of the H-4 Pond in fall of 2025, weather permitting, the pond will add another five and a half million gallons of water capacity. The three ponds together will have the ability to retain approximately 13 million gallons of water during severe storms, which is equivalent to a football field filled with water, 30 feet deep.

The NC-3 Pond is currently in the final design and permitting stage, the T-1 Pond is in the planning and preliminary design stage and the Maryland Avenue Culverts project is in final design.