By Timothy B. Wheeler
With Baltimore facing increased risks of coastal flooding from storms as sea level rises, federal officials have put forward a $138 million plan aimed at protecting the interstate highway tunnels under the city’s harbor while reducing flood damage to homes and businesses in low-lying waterfront neighborhoods.
The draft plan released last month by the Baltimore District of the U.S. Army Corps of Engineers proposes to build floodwalls around the openings to the Interstate 95 and Interstate 895 tunnels that carry traffic beneath the harbor. Flood barriers would also shield the ventilation buildings that circulate fresh air into the tubes.
For the tourism-centric Inner Harbor and waterfront neighborhoods like Canton, Fells Point, Riverside and Locust Point, the plan doesn’t envision erecting any levees or other structures to hold back the water. Instead, it calls for floodproofing vulnerable buildings to the greatest extent possible, given their age and condition.
“The goal is to mitigate damage,” explained Joseph Bieberich, project manager for the Baltimore District’s coastal storm risk management feasibility study.
The draft plan is the product of a three-year study for which the Maryland Department of Transportation picked up half of the $3 million cost. It’s an outgrowth of an earlier Corps study of East Coast flood risks, which projected that sea level in the harbor could rise from 1.0 to 5.4 feet by 2100, depending on the severity of climate change.
The Baltimore metropolitan area has felt the effects of at least nine hurricanes or tropical storms since the 1950s, the Corps study noted. The most severe hit came from Tropical Storm Isabel in 2003, when storm surge and heavy rains inundated the Inner Harbor and neighborhoods in Baltimore County with up to 8 feet of water. It caused $4.8 million in property damage in the city and up to $252 million in total damages in the county. One person died in the floods, while more than 570 homes and 15 businesses were declared uninhabitable.
Even without storms, portions of the area experience tidal flooding several times a year, particularly the Inner Harbor promenade and the mix of businesses and homes in lower Fells Point. With climate change pushing the sea level higher, the National Oceanic and Atmospheric Administration predicts the city could experience anywhere from 50 to 160 nuisance flooding events by 2050, inundating a broader swath of the waterfront.
Between storms and nuisance flooding, the Corps plan says, more than 1,400 structures would be at risk by 2080.
The draft plan focuses almost exclusively on the city, although flood risks extend throughout the metropolitan area. Beyond looking at protecting a state-owned airport on Middle River, Corps planners did not address flood risks in Baltimore County, even though it bore the brunt of Isabel in 2003. Bieberich said that county officials declined to participate in the planning effort.
County officials contacted by the Bay Journal about the decision not to participate said they were unfamiliar with it and unable to explain why.
The only nonfederal partner for the study was the Maryland Department of Transportation, which runs the Martin State Airport in Baltimore County and has responsibility for the harbor tunnels.
The study originally looked at 10 options for dealing with flood risks along Baltimore’s waterfront. Two involved building storm surge gates across the Patapsco River near where it joins the Chesapeake Bay, at a projected cost of $1.3 billion to $1.4 billion. Though the gates would have provided the broadest protection from storm-driven flooding, planners ruled them out, saying that strategy would rely too much on a single control measure and could impair water quality in the harbor.
Planners winnowed their original scenarios down to five alternatives that ranged in cost from $62 million to $673 million, depending on the amount of physical flood barriers and floodproofing proposed.
Dropped along the way were proposals to build floodwalls at the Dundalk and Seagirt marine terminals, hubs of shipping and commerce for the region. The Maryland Port Administration, part of the state transportation department, is already pursuing its own flood control plans for the Dundalk facility, according to the study.
The planners also dropped proposals that would have elevated the pedestrian promenade around the Inner Harbor and built floodwalls along various waterfront neighborhoods. While 7-foot-high barriers might keep streets and buildings dry, they would restrict access to and views of the water.
“We determined the community would not support that,” Bieberich said.
The city has had its own plan since 2013 for dealing with storm and flood damage and for addressing climate change impacts, which has been periodically updated. It also has a nuisance flood plan. The Corps plan references them.
In other flood-prone areas, vulnerable homes and other structures have been physically raised above projected storm surge levels. Planners thought that wouldn’t be feasible for the historic structures in neighborhoods like Fells Point and Canton. Instead, the plan calls for installing door and window barriers, raising ventilation units and other mechanical systems off the ground, and putting water-resistant materials in flood-prone basements and ground floors.
That approach “reasonably maximizes net benefits while maintaining historic neighborhood character, access to water, and enhancing community resilience,” the study concluded.
If the plan is ultimately approved, the federal government would pick up 65% of the cost of designing and building seawalls around the harbor tunnel openings, with the state or other nonfederal partners covering the rest.
The $138 million projected cost is mainly for the physical flood barriers. Floodproofing the Inner Harbor and waterfront neighborhoods would be up to property owners. Bieberich said it’s possible that the federal government could offer financial support to encourage their voluntary participation, but that has not been decided.
The draft plan must be finalized and receive authorization and funding from Congress before preliminary engineering and design work can begin.
The Corps and state transportation department are holding two public meetings to present the plan, answer questions and take feedback.
The first meeting will be in person, 6–7:45 p.m. Monday, Aug. 1 at the Enoch Pratt Free Library, Southeast Anchor Branch, 3601 Eastern Ave. The second meeting takes place virtually, 6–8 p.m. Tuesday. To join the virtual meeting, click on this link.
Comments on the plan will be considered until Aug. 19. For information on the plan or to submit a comment, go here.