This article originally appeared in the latest issue of History News, AASLH’s member magazine. Members can access a digital copy of the issue for free in our Resource Center.
By Rodney Rowland, Director of Environmental Sustainability, Strawbery Banke Museum
Let’s be honest with ourselves: historic preservation has gotten harder over the last few decades. So many new and shifting challenges need to be addressed when protecting, the history of this nation for generations to come. Changes in building materials, attacks from unknown pests, paint recipes that change monthly and, a growing danger, water. We could debate for some time the reasons why, but that is not the point of this article. Winning the war on these threats to historic preservation is the goal and a major concern at my own site.
Strawbery Banke Museum is an outdoor living history site in Portsmouth, New Hampshire, consisting of nine acres and thirty-two historic buildings on their original foundations built between the seventeenth and nineteenth century. This campus is blessed with a geographic location in downtown Portsmouth that is both picturesque and a growing destination for tourists. Unfortunately, the campus is also prone to flooding from both surface water and groundwater. Tidal impacts from the nearby Piscataqua River influence groundwater levels (called upwelling) until they impact our building basements. Water-impacted basements, in turn, cause extremely high relative humidity levels for extended periods of time. This leads to more rapid decay of most building materials and damage to vital utilities. In addition, large rain events deposit stormwater on the campus, a low point in the South End neighborhood, which ponds around our buildings and blocks visitor access. The frequency of these events is increasing and recently hit a new high when a storm in January 2024 saw the highest ever recorded tides in the Piscataqua River combined with many inches of rainfall—the perfect storm for multiple building and site-wide impacts.
The center of the Strawbery Banke campus is a large field that was once a tidal inlet called Puddle Dock, a safe harbor that played a significant role in the development of this historic site and the city. The waterway was filled in by the city of Portsmouth in 1902-1903. This one action further complicates our flooding impacts since our “connection” to the river, where all our stormwater ends up, was cut off except for a single 30-inch pipe when Puddle Dock was filled in.
The question now becomes: how do we manage all this water at our site until the one pipe can send it on its way? Like most of the field, our museum staff consists of historians, fundraisers, and educators, not plumbers or water engineers. We have no backgrounds or skill sets that make us competent to answer this crucial question. So we get help, form partnerships, and build a team. Out in our communities are a growing number of experts like landscape architects, civil engineers, hydrologists, and environmental services to help us solve this challenge. Once we have defined the impacts, we can better define the people whose help we need to be successful.
More and more landscape architects are specializing in this kind of work. Strawbery Banke Museum hired one along with an architect to develop a site-wide stormwater plan in June 2023 to identify the causes of surface flooding, the impact areas, and the general “tools” we can use to mitigate these problems. Some of these tools sound like common sense. Did you ever play at the beach controlling the incoming waves or tide by building moats, canals, and walls? Same idea. With smart design, we can reduce (less water, less impact), capture (dam it up), store (hold it in a specific area), and control (move it along in safe areas) the water away from the areas that will cause damage. One, or likely more than one, of these tools will work to solve flooding impacts. As an example, the flood-prone area in our management plan known as “Area of Concern 2” is caused by city stormwater entering our site from Washington Street combined with runoff from the higher, northern boundary of Strawbery Banke. The solution involved the use of several of these “tools” through the creation of a number of landscape changes. Specifically, two rain gardens or bio-retention ponds, three drainage swales, and one sidewalk “dam.” This coupled with a regrading of the museum’s roads in this area will completely redefine how the flood waters flow through this area, keeping it away from the historic houses and into the created management areas.
In all, the museum’s campus has nine areas that will need this type of stormwater treatment. We are working on all of them to some degree, but in different phases from planning to design to implementation. As we look deeper into each impacted area, we keep in mind our main mission to teach the history of our museum’s neighborhood. Are there crossover areas where stormwater management and site history interconnect? We are finding the answer is a resounding “yes!” As the museum and the design team plan future work, we look to create a bio-retention pond that evokes the look of the old tidal inlet with wharves and native plants. We then strategically place site signage with historic images of the old inlet before it was filled in. Planning also involves the retoration of an important archaeological site which today is nothing more than sections of an old foundation in the grass. We’ll then use this foundation for storing stormwater and to tell the story of the Marshall Pottery site, which produced vital redware vessels for the local community and had three enslaved individuals laboring there.
We are storing stormwater and teaching history at the same time.
Unfortunately, surface water treatments or mitigation strategies only get Strawbery Banke part of the way to resiliency. You may recall the site is also plagued by groundwater impacts or groundwater intrusion. This has to be handled in a slightly different way and with a slightly different team of partners. One partner in finding groundwater solutions is the University of New Hampshire Geospatial Science Center.They installed and maintain for Strawbery Banke a groundwater sensor network studying how groundwater is moving on our site. This information is vital to finding the right strategy to protect our historic resources.
An important structure benefiting from this strategy is the Penhallow-Cousins House. The 1750 building was moved to the site in 1862 when it was an active, growing residential neighborhood, long before the museum was created. The chosen site was reclaimed land, part of the Puddle Dock tidal inlet, that was the out-flow to another body of water known as the South Mill Pond. In fact, archaeological investigation of this area prior to the foundation work on the house uncovered a cobble spillway feature, indicating attempts at early water management from the late eighteenth century. In 1862, the house was placed on a loose stone foundation with a dirt floor. As groundwater levels increased over the decades, the basement was plagued by high humidity levels and later impacted by standing water as well. The result was rapid decay of both brick and wood structural elements of the house. Looking at our treatment options, we chose a new wet-proof foundation that allows groundwater to drain in and out freely. The entire foundation, inside and out, has perforated pipes connected to the city storm water system to manage this groundwater. Flood vents on the rear elevation of the new foundation and a sump pump add protection from water impacting the undercarriage of the house.
The decision to remove this historic foundation was not an easy one, but we must find the balance between historic preservation and resiliency.
Each location and example of water impact must be studied and understood to determine the best course of action. Fortunately all the treatments available to us are now part of the National Park Service Guidelines on Flood Adaptation. The guidelines are flexible by design since each case will bring unique qualities needing unique solutions. Each successful adaptation will land somewhere on the line between historic preservation and resiliency. It is finding the balance that takes time and plenty of support.
The moral of this story is solutions are there to battle these new and growing threats, but success is dependent on seeking the partnerships one needs to formulate a plan. In this example, it really does take a village. Strawbery Banke is blessed with help from paid consultants, volunteers, state and city employees, and the greater community as a whole. We also seek advice from a regional group called the New Hampshire Coastal Adaptation Workgroup. This is a volunteer-run organization whose mission includes helping with the regional response to flooding. Its members represent numerous disciplines offering an incredible opportunity for those needing guidance. More and more of these types of regional groups are popping up, so find out if your community has one. A favorite partnership came from the local Piscataqua Garden Club. They awarded us a grant for the native plants that would go in our new rain gardens and then came on-site to plant them. It takes a village!
Lastly, it is important to talk about the role of museums and other publicly accessed institutions as we navigate these difficult waters (pardon the pun). We all have a unique opportunity to educate and engage the visitors to our sites. We are, in part, a stage set where we can tell many stories, offer many experiences, and create memories with them. While many of us have done this for years when it comes to history or science, it is important we consider doing this for the causes that effect all of us. Flooding is not unique to Strawbery Banke Museum. In fact, the oldest settlements around the world tend to be located on bodies of water due to the need for sources of food and modes of transportation. Many of these sites are at risk today for flooding. So do we not have an obligation to teach or inform about these impacts and the possible solutions? Should we not teach what we learn as we deal with these issues in hopes of helping others and their communities?
Strawbery Banke embraced this role in the creation of a temporary exhibit called Water Has a Memory: Preserving Strawbery Banke and the City of Portsmouth from Sea Level Rise. A partnership with the City of Portsmouth Department of Public Works (DPW), this exhibit helped both organizations communicate with the community about their important projects related to stormwater. The DPW, for example, has an ongoing project called “Think Blue! What Can You Do?” to protect and mitigate stormwater. These partnerships are critical to success and so beneficial to the larger community. Also in this exhibit was a touchscreen interactive that explores the changing landscape of the Puddle Dock tidal inlet. While demonstrating this change over time, we also included what change might occur if we are successful, or not, in becoming resilient. This interactive touchscreen was so popular it is now part of the visitor introductory experience in the museum’s visitor center. The exhibit was up for four years before being retired, but was so critical to mission and messaging that we hope to have a permanent installation in 2027. This certainly speaks to the importance of public outreach and community partnerships.
While we think about public outreach, we can explore the role of history in our current situation and the role the very objects and buildings we are tasked with preserving might have played in the development of threats we are seeing today.
Many years ago, I was the object conservator for the Abbott Grocery Store Project at Strawbery Banke. We were restoring a circa-1720 house as a well-loved community mom and pop grocery store from 1943. This store was in existence from 1919 to 1952, but we targeted the World War II era to talk about life on the American homefront. I was responsible for preparing the 2,500 objects that would go on the store shelves, everything from packs of cigarettes to cans of Spam.
One such object was a coal bag from the Charles E. Walker Coal Company (1882-1951). Walker Coal was a large coal plant right on the banks of the Piscataqua River, within sight of where Strawbery Banke is located today. This object was an exciting and important gift to the museum as we developed the story of the Abbott store, a piece of Portsmouth’s history that played a big role during World War II (coal was the main source of heat and fuel on the homefront during the war as other fuels were sent overseas). But of late, we also begin to look at objects and their longer-term impacts. Did the mining and burning of millions of tons of coal have a longer, sustaining impact on our country’s history? On our country’s future? These are hard, thought-provoking questions. In the book White Pine by Andrew Vietze, we learn the amazing history of this country through the “eyes” of the White Pine tree. Think of the number of objects in our collections made of this valuable resource, nevermind the number of historic houses built of white pine. Vietze clearly shows us the importance of this resource to the history and development of our nation. We can tell national and even global stories from even humble artifacts, including how historic industries and practices impacted the threats we deal with today at our sites.
It is stated at many public history and museum conferences that organizations that depend on visitation as an income source need to ensure they are relevant to today’s society and that they make connections with visitors in relevant matters that are important to them. Disasters and threat mitigation are increasingly relevant to so many of our visitors’ current and future lives. Our daily lives are bombarded by stories of natural disasters of historic proportions; events that impact lives and that require a nation-wide recovery response that consumes increasingly considerable resources, including financial. Interpreting our own environmental challenges and solutions and the historic context in which they developed is a valuable point of connection and relevancy with visitors today; a connection that I would argue will matter to more and more people as time goes by.
Rodney Rowland is the Director of Environmental Sustainability at Strawbery Banke Museum in Portsmouth, New Hampshire. His 35-year career at the museum has always focused on preservation, but the current task of flood resiliency is the largest undertaking in the museum’s 73-year history. To learn more, please visit strawberybanke.org/sea-level-rise. Contact Rodney at [email protected].
