A rising tide may lift all boats, but how will rising sea water levels affect the redevelopment of Harborplace?
That’s one of the big issues facing city planners as they scrutinize MCB Real Estate’s recently-unveiled plans to replace the two Harborplace pavilions at Pratt and Light streets with a mixed-use development costing $500 million.
To assist the city, the Waterfront Partnership of Baltimore has hired a New York-based resiliency expert called SCAPE Landscape Architecture to provide advice regarding the rise in sea water levels that’s expected to occur at the Inner Harbor due to global warming.
Specifically, SCAPE has been asked to prepare a report to give city leaders guidance regarding how high sea water levels are likely to rise in coming decades and how frequently certain sections of the Inner Harbor promenade and adjacent land will experience flooding as a result.
SCAPE’s findings will help city planners decide how to modify Baltimore’s harbor promenade and bulkheading to keep the area accessible to the public and support redevelopment efforts along the shoreline.
The existing Inner Harbor promenade, which was completed in the mid-1970s, was designed so the public walkway would be 7.5 feet or more above Mean High Water – a method of measuring sea water levels at high tide – and not be prone to frequent flooding.
In recent years, studies have indicated that sea water levels at the Inner Harbor could rise anywhere from four to 10 feet or more, depending on the pace of global warming and how many years in the future one projects.
Portions of the city-owned promenade, especially around the Inner Harbor amphitheater between the two Harborplace pavilions, now flood on a regular basis, especially after heavy storms but at other times as well.
SCAPE is an award-winning landscape architecture and urban design practice that has worked with leaders of a number of coastal cities and states seeking advice on how to make their waterfronts more resilient in an era of rising sea water levels.
The company was founded in New York in 2007 by Kate Orff and now has offices in New Orleans and San Francisco. In 2017, Orff became the first landscape architect to receive the prestigious “Genius” Fellowship from the John D. and Catherine T. MacArthur Foundation. In April, Time magazine included her on its 2023 list of the “100 Most Influential People in the World.”
SCAPE’s clients include New York City; Boston; Jacksonville, Florida; Memphis, Tennessee; Mobile, Alabama; Hoboken, New Jersey; Auckland, New Zealand; the Louisiana Coastal Protection and Restoration Authority, and many others. Pippa Brashear is SCAPE’s Resilience Principal and Partner.
In Baltimore, the area around the Inner Harbor amphitheater and water taxi stop is particularly vulnerable to flooding because it is lower than the promenade half a block east, in front of the Pratt Street Pavilion of Harborplace. The promenade slopes downward as one walks from the World Trade Center to the amphitheater, and that’s where flooding occurs more than anywhere around the harbor basin.
One way to address flooding, planners say, is to raise the height of the promenade to keep it above rising water levels. But to what elevation should the promenade be raised? Does the city want to prevent all flooding or just most flooding? How many flooding incidents a year would be considered acceptable? One? Five? More? How far in the future should the city look – 2030? 2050? 2100? Those are the variables the resiliency consultants are exploring.
City officials say the Waterfront Partnership is involved because the city planning department is short on staff and has numerous other studies underway, including planning for the Red Line transportation route. They note that the Waterfront Partnership has led other planning efforts, including designs for West Shore Park and Phases 1 and 2 of the Rash Field Park makeover, as well as the Baltimore Blueway plan, a proposed network of eight water trails and 20 access points that will connect communities and landmarks throughout the Inner Harbor and Middle Branch of the Patapsco River.
On Thursday, the Waterfront Partnership is scheduled to unveil its 2023 “Healthy Harbor Report Card,” the latest in a series of annual reports tracking water quality, ecosystem health and restoration work affecting Baltimore’s harbor and streams.
SCAPE’s study is being funded with money that the city planning department allocated to the Waterfront Partnership more than a year ago for another study, unrelated to sea level rise. The Partnership had money left over after completing that study and is now using it to engage the resiliency expert.
The Waterfront Partnership advertised for a consultant earlier this year and received expressions of interest from two companies, SCAPE and one other firm. The second firm was deemed unqualified to provide the information the city it is seeking, and SCAPE was hired.
Laurie Schwartz, president of the Waterfront Partnership, said the consultants are working with both her organization and the planning department, and she expects to receive a report on their findings shortly.
Because the Waterfront Partnership is not a regulatory agency, she said, any decisions about raising the promenade’s height or otherwise modifying its design will be made in collaboration with the planning department and other public agencies.
In addition to the Inner Harbor study, planners say, the city needs resiliency experts to take a comprehensive look at the potential impact of sea level rise on shorelines elsewhere in Baltimore, including the stretch from the Inner Harbor out to Canton and the stretch from the Inner Harbor out to Locust Point, with special attention on areas that flood in Fells Point and other low-lying communities.
Planners say any larger study also could be carried out as a collaboration between the Planning Department and the Waterfront Partnership, but it hasn’t yet been funded and a consultant hasn’t yet been identified to lead that effort.
The Inner Harbor basin was chosen for the more focused study because that’s where MCB Real Estate wants to replace the two Harborplace pavilions with residential towers, offices, shops, restaurants and expanded public space, according to preliminary plans unveiled on Oct. 30. Before the developers can finalize their designs, planners say, they need projections about sea level rise and how it will affect the buildings MCB wants to construct and the public spaces around them.
MCB’s design team, led by Gensler, includes several firms that are working to redesign the promenade and other public spaces, including Unknown Studio, a landscape architecture and urban design firm; Biohabitats, an environmental consultant; and Moffatt & Nichol, an engineering firm that specializes in designing infrastructure improvements and other facilities that shape and serve coastlines.
During a community meeting about Harborplace in South Baltimore on Nov. 6, Baltimore City Council member Eric Costello noted recent news reports that stated the cost to taxpayers of rebuilding the promenade and completing other public infrastructure improvements related to the Harborplace project could be $400 million, over and above the $500 million in private funds MCB intends to invest. Costello said $67.5 million has been secured from the state of Maryland, including $37.5 million which is already on hand and another $30 million that has been committed.
“Those infrastructure improvements are going to go to a number of things, but mainly improvements to the promenade and traffic improvements along the Light Street and East Pratt Street corridor,” Costello said.
When the promenade was built 45 to 50 years ago, “it was federal dollars that paid for the promenade — not the City of Baltimore, not the State of Maryland — and a little over 40 years ago there were additional improvements made to the promenade, and those improvements were funded solely from federal dollars,” the councilman said. “So there is an expectation, as the federal government has always been responsible for the promenade, that we will work with our federal partners and they will step up to help support the improvements that are necessary for the promenade.”
Noting a time in early 2022 when the promenade was one and a half feet under water after a heavy snowstorm, Costello said it’s critical that any plan to reconstruct the Inner Harbor promenade address resiliency concerns.
“We are lacking significant climate resiliency in the design” of the existing promenade, he said. “That’s a problem that does need to be addressed as we think about global warming.”
“We’ve got to face facts,” added MCB managing partner P. David Bramble, at the South Baltimore meeting. “This thing floods. And it can’t continue to exist in the form that it’s in if we want to have it, so significant work has gone into dealing with the resiliency issues.”
MCB’s plan for making the area more resilient to sea level rise calls for rebuilding the Inner Harbor promenade so it has two levels, an upper promenade on land and a lower promenade that’s designed to float on the water, rising up and down with the tide.
The two levels will be connected by a ramp system and will be fully accessible to people in wheelchairs. MCB’s plan also calls for floating wetlands along with the split promenade.
According to Unknown Studio partner Claire Agre, MCB’s design calls for the width of the promenade to increase, from 30 to 45 feet at present to as much as 60 feet wide for the upper promenade and 30 feet wide for the floating lower level.
In a presentation at Coppin State University on Nov. 3, Agre said MCB’s design calls for the split promenade to stretch from the Maryland Science Center north to the Inner Harbor amphitheater and then east towards the World Trade Center.
The corner where the amphitheater is now will be raised and redesigned with a curving walkway along the water’s edge, dubbed the Crescent. The Inner Harbor water taxi step will be relocated from the amphitheater to the southern end of Pier 1, where the USS Constellation and its visitor center are relocated.
Where the promenade floats, it will always be right at water level, Agre said. “That’s part of the beauty of floating.”
Where the promenade is fixed, she said, the walking surface will be at about seven to nine feet above sea level, whereas the current promenade is about two to six feet above sea level. The lowest point of the new promenade will be at the curving Crescent area. At present, the walkway at that corner of the harbor is about two and a half feet or three feet above sea level and is “almost always flooded,” she said.
Agre said the upper promenade will be about four feet higher than the promenade is today and the design calls for no guardrails along the walkway, a characteristic that people like very much about the current design. The plans also calls for the addition of about 500 to 600 native trees to provide shade for both the upper and lower promenades.
Nod to history
Materials will go from being mostly brick at present to some variation of paving or gravel for the upper promenade and wood used for portions of the floating lower promenade, such as docks and fenders, and for the Crescent, Agre said.
The use of wood is a reference to a time before Baltimore’s Great Fire of 1904, when wood was a prevalent building material, she said.
Before the 1904 fire destroyed much of downtown, “you see the kind of knowledge and construction and the shipbuilding, all this incredible craftsmanship in Baltimore which was made with wood,” Agre said. “That all disappeared after the Great Fire. We kind of lost that part of our identity. So this is bringing back that kind of know-how, that knowledge and that identity in the lower promenade.”
Agre and Bramble said people who are in a hurry to get from one side of the harbor to another likely will use the upper promenade, while people who want to take their time and explore the waterfront will have the option of using the lower promenade.
“One of the things that we heard over and over again about the promenade is it’s beautiful, we love it, we like to go there with the family, but there’s no shade, there’s no place to sit, and we want to see that change,” Bramble said at the South Baltimore meeting.
With the new configuration, “the first level will have lots of seating and trees for shade, and the lower level floats so that you can deal with the resiliency issues,” he said. Once it’s in place, “you have two opportunities to interact with the water, one above and one below.”
Giving people more choices in the way they interact with the public realm was a key goal of the design, Agre said.
“In the footprint of today’s promenade, we made this a lot more complex,” she said. “There’s a lot more choices. There’s a lot more habitat value. There’s water quality improvements. There’s shade. There’s urban heat island mitigation. That’s really important because there’s no such thing as a one-size-fits-all public realm. This is meant to be for everybody.”
How much of the existing promenade will be torn out and rebuilt?
“It’s a little bit early to say exactly how much of the existing structure can be retained,” Agre said. “It is at the end of its functional life…I would say we are working within the existing footprint. We are pragmatic.”
Agre said the marine engineer on the team, Moffatt & Nichol, is just starting a feasibility study regarding the condition of the bulkhead and seawall at Harborplace, and that will indicate how much can be retained. For now, “there’s a lot of information to understand,” she said.
Endorsed by SCAPE
Adam Genn, vice president of MCB Harborplace, said at the South Baltimore meeting that MCB’s design team has worked closely with the city’s planning department and the Waterfront Partnership to develop its resiliency plan for Harborplace. He said MCB’s design team has shared its plan with SCAPE, and SCAPE supports its multi-pronged approach. “I think…SCAPE would say they’ve endorsed this plan based on our strategy,” he told the audience.
Genn took several minutes to explain how MCB arrived at its resiliency design.
In planning a new promenade, he said, “we look at both what we call the ‘emissions models’ as well as the climate projections from the Paris Climate Accord,” he said. “What we look at is, if emissions continue as they currently are and we don’t mitigate anything, what is the sea level rise that we’re going to project by 2100? And then we look at the probability of flooding within that time frame and we determine what is something that we as a city can be comfortable with.”
Based on feedback the planning department received from outreach efforts involving more than 23,000 people, Genn said, “what folks determined in the city of Baltimore was we’re OK with the promenade flooding once a year, having roughly a 20 percent chance of that happening. That is at the lower elevation that we’re designing to today. So the upper promenade is designed to be dry in almost every condition that we project,” other than a once-in-1000-years hurricane.
The floating wetlands and other plantings in MCB‘s design are intended to intercept pollutants that currently wash into the harbor after storms, he told the audience.
“The entirety of this area as it exists today is red brick – it’s impervious — and the water sheets directly off of that and into the harbor and pollutes the harbor,” he said. “And by the way, it goes directly from Light and Pratt streets and moves into the water as well. That has petroleum in it. That has everything that’s on our streets that we don’t want in the Chesapeake Bay. And so when you look at our plans, you see the wetlands, you see the intercepting green space along the upper promenade and the lower promenade. The goal here is to intercept stormwater before it enters our system so that we have a healthier bay, a healthier harbor, and one day we can go in there and swim.”
‘A conversation about risk’
During the presentation at Coppin State University, Genn and Agre acknowledged that cities are limited in the degree to which they can prevent sea level rise, but they said cities can still take steps to prepare for it.
“There’s a curve,” Agre said. “We know what the absolute worst projection could be and we know what the absolute rosiest projection would be, and it’s a conversation about risk — what’s our acceptable level of risk?”
MCB’s resiliency plan is not climate-proof, but it is “climate-adaptive,” she said. “The water will come, the water will go. We know that. The floods will increase. We know that. But we’re creating a place that’s very flexible and adaptive and can handle that ebb and flow.”
“We don’t know what’s coming,” Genn agreed. “But we can do our best to mitigate it.”