On a crisp October morning, Rodney Rowland wore a thick brown jacket, its warm layers protecting him from gusts of biting wind that blew off the Piscataqua River. Rowland, director of special projects and facilities at Strawbery Banke in Portsmouth, stood on the outskirts of the museum’s 10-acre grounds, home to deep red and mustard yellow houses, the oldest of which date back to the late 17th century.
Where Rowland stood, barges once traveled a nine-foot deep canal carrying European goods to the colonists living in what is now Portsmouth, New Hampshire. More than a century ago, that canal, called Puddle Dock, was filled. But now, rising waters are reclaiming their place amid the structures of Strawbery Banke. Rowland sees the water taking the path of least resistance: the basements of Strawbery Banke’s historic homes.
“We are the ground zero for sea level rise in Portsmouth,” Rowland said.
Walking towards the Sharpley-Drisco House, one of Strawbery Banke’s 37 historic structures, Rowland whistled an unrecognizable but charismatic tune that seemed at home among the old, charming houses. From the outside, these homes look untouched by the effects of climate change that threatens to destroy the integrity and original construction of the museum structures. But in the basements that is not the case.
“As is the case with all museums, we are stewards, we are the protectors of the history that is in our houses,” Rowland said. Sea level rise and flooding are “affecting our ability to be the stewards, the protectors of that history.”
There is more carbon dioxide in the atmosphere than at any point in the past 800,000 years, triggering warming air, melting ice, and rising seas. According to the March 2016 draft of a report by the New Hampshire Coastal Risks and Hazard Commission (CRHC), sea levels have been rising at approximately 1.3 inches per decade since 1993. The draft report states that the rising base-line is caused by melting of Antarctic and Greenland ice sheets, baseline glaciers, and the rising temperature of the ocean. The current and future greenhouse gas emissions in the atmosphere will accelerate rising sea levels, according to the CRHC. This means that by 2050, the New Hampshire sea-level baseline could rise as much as two feet, and projections show by 2100 base-line levels could rise up to 6.6 feet.
According to the Sea Level Rise Vulnerability Assessment of Coastal Resilience in New Hampshire, 22 of Strawbery Banke’s historic buildings are located in inundation zones if sea levels were to rise .99 to 1.6 meters, or 3 to 5 feet; a foreseeable situation according to the CHRC 2100 predictions.
Kirsten Howard, a coastal resiliency specialist with the New Hampshire Department of Environmental Services, noted that in addition to the rising waters, between 1901 and 2012 the Granite State has seen a 50 percent increase in extreme storms, in which large volumes of precipitation fell within 24 hours, overflowing drains and other infrastructure. With the baselines rising, storms that were not a problem in the past will begin to cause flooding, which will damage the integrity of historic resources, such as Strawbery Banke.
The Sharpley-Drisco House sits on the edge of Puddle Lane, a stone’s throw from the Piscataqua River’s edge. Its well-kept white exterior gave no illusion to the damp and rotting basement within the colonial structure. The house was built in 1790, and to this point there have been no plans to change the original construction of the home.
As Rowland continued his walk toward the entrance of the frequently flooded home, just two feet under his stride the groundwater levels crept closer to the surface. According to Rowland, the drains installed to carry floodwaters away from the historic grounds are beginning to fill with salt water. With flooded systems, excess rainwater from the increasing storms has nowhere to go, except the basements of Strawbery Banke’s houses.
“The houses, they are the backbone of what makes Strawbery Banke Strawbery Banke,” Rowland said. “If you took away our houses, and the objects in the houses, you have nothing.”
Stepping inside the Sharpley-Drisco House transports Rowland back to colonial times when the large home sat on the bank of Puddle Dock. Shelves hold spices, candles, animal furs and handmade household items. Wooden dining room tables are set with handmade chairs, in the adjacent fireplace sits an unlit fire, waiting for someone to light it and warm the house after a long day of work. To a student or tourist visiting the museum, the structure would seem safe and unexposed to the changing climate around it. It was not until Rowland hunched down to squeeze through the small basement staircase that the extent of the damage was noticeable.
Portsmouth’s Environmental Planner and Sustainability Coordinator Peter Britz said the city is currently drafting a historic study pinpointing the vulnerable structures within the city. Though the process is still under way, the city will work with a local advising committee and an engineering firm to plan ways Portsmouth can protect and restore its historical district while keeping infrastructural integrity intact.
“The vision of the town is to protect that integrity,” said Britz. “This will be done by trying to keep the town looking the same, and keeping its character.”
In April, 2013, Portsmouth published a Coastal Resilience Initiative, the city’s first look at how it will be impacted by rising waters. This report highlights plans to protect Strawbery Banke, along with other sites, by raising structures, and building floodgates and walls depending on the level of sea level rise.
The CRHC states that cultural resources include historic buildings, archaeological sites, and institutions such as libraries and museums. These resources, according to the draft report, represent not only a tangible history, but also the history and culture of the people who lived there decades ago.
Sense of place is defined by the CRHC as the connection to the history of a given location demonstrated by the use of community landmarks. In Portsmouth, the use of its historical infrastructure, like the houses in Strawbery Banke, creates a strong sense of place in the city. The CHRC emphasizes the importance of such historic structures for economic, touristic and practical use; however, once a historic building is compromised, its original integrity can never be restored.
From the steep steps into the basement of the Sharpley-Drisco House, a smell of damp earth filled the stagnant air. Rowland ducked his head to avoid hitting rusty gas lines. Moss clung to the original foundation, and elevated wooden supports rotted where the water had risen above their raised base.
Rowland looked around him shaking his head. “It’s a mess,” he said.
The moisture in the basements creates rot and rust in the foundation of the houses. The space in the walls left for moisture to escape is now filled with insulation, leaving excess condensation, which bubbles the exterior paint.
Damage from the effects of global warming is occurring at 1,000 historical sites in 163 countries around the world. UNESCO’s World Heritage and Tourism in a Changing Climate report states that 29 countries, including Japan, Greenland and the United Kingdom, are already seeing these negative effects.
One of these places is Old Town Lunenburg Canada, a waterfront town rich in fisheries and tourism threatened by the inundation of water, according to UNESCO’s report. Among the vulnerable roads and infrastructure is the town’s historic waterfront museum, Fisheries Museum of the Atlantic, which pays tribute to the Canadian Atlantic fishing heritage.
Meghan Howey, associate professor of Anthropology at the University of New Hampshire, said humans and the seacoast have a historic relationship. Because of its conveniences people settled near the water, so much of New Hampshire’s cultural heritage is vulnerable to the effects of sea level rise. Howey’s research has concluded that if emission levels remain consistent in the future, by 2100 19% of New Hampshire cultural heritage sites will be inundated by water, meaning the very foundation of the seacoast is under threat.
“We live on a very large flowing river,” Rowland said. “That is going to be an issue and how to battle that issue is going to be first and foremost.”
Though it does compromise the integrity of the historic houses, Strawbery Banke is in the process of adapting their property to better withstand the flooding caused by rising sea levels.
The Lowd house sits to the left of the Sharpley-Drisco house, slightly farther away from the Piscataqua’s riverbank. The original brick foundation was replaced with granite, a less soluble rock that will absorb less water than the original brick. According to Rowland an 1810 cool cooking stove, used by colonials during hot summer days, was removed during this construction due to the extensive erosion to its base. The basement was finished last June, but despite the improvements, moss is beginning to grow on the new granite foundation.
“We don’t like taking out original material,” Rowland said. “But there is no other way to stop it.”
Along with reconstruction, Strawbery Banke is installing Disaster Preparedness kits in its houses. Rowland says these kits will give staff the tools they need to fix a broken window, or a leak during a storm that may endanger the antiques within the house, and the house itself.
Historic sites, according to Howey, are a point where people can begin grasping the severity of climate change’s impact. Unlike newer construction, mitigation and adaptation strategies chip away at the integrity of historic structures. These locations in Portsmouth and all over the world are tangible examples that once something is gone, it’s gone for good.
“Every community has distinct cultural heritage that we are attached to,” Howey said. “Cultural heritage grounds communities to their identity. If we lose that, what does it mean?”