Learning from the Swollen Rivers of the Past

by Tom Peace on October 15, 2012

By Thomas Peace

I may be cursed. Everywhere I move flooding seems to follow.  Last fall, my family and I moved to White River Junction, Vermont. On an apartment hunt, my father and I arrived in the Green Mountain State immediately following Hurricane Irene.  Pulling into Rutland we were told that there were no roads open that crossed the state east to west. Every road had been washed out. Indeed, the devastation Irene caused was still a lead news story in the area when we left at the beginning of August, a year later. We arrived in Nova Scotia to some dry weather, but here too we’ve seen one of the wettest September’s on record.  One of these weather systems, associated with Tropical Storm Leslie, broke through a number of dykes around Truro, bringing significant flooding to Nova Scotia’s “Hub Town.”

There are a lot of differences between these two “weather events,” not the least of which was their scale and damage. What links them together, though, is that in both cases similar flooding had taken place in the past. Although these events are tragedies, much of the damage was predictable, though not always avoidable.

Often the harm that results from a flood has historical, economic and social roots. In the northeast, towns often developed around mills, bridges or rich alluvial soils that encouraged their growth onto a flood plain. As we saw during Hurricane Katrina, these low-lying areas were (and are) home to communities of less-affluent residents and industrial/commercial development. Both factors often lead to poor planning and government decision-making, another important cause of flood damage. For these reasons, we should be hesitant to call these events “natural disasters.” Even in extreme instances, much of the devastation caused by flooding is seldom unprecedented and it is often predictable.

In August 2011, Hurricane Irene brought severe flooding to the State of Vermont. Floods claimed six people’s lives. In writing this post, I don’t want to diminish the significance of this event. The flooding that struck Vermont in August 2011 was devastating. But, I think, it is also important to recognize that it was not unprecedented and that some damage was preventable.

Flooding is the most likely natural disaster to affect Vermont. Situated in a mountainous topography, heavy rainfall and snowmelt makes its way down into rivers and streams much faster than on a flatter landscape. Frozen or saturated ground enhances this problem, leading to flash flooding and swollen rivers. On an annual basis, somewhere in Vermont is visited by flood. According to one study on the state’s flood history by Leslie-Ann Dupigny-Giroux , Vermont averages over 16 million dollars in flood damage each year.

Hurricane Irene was the worst storm to hit Vermont in nearly a century. Its only rival was the Great Flood in 1927.  This flood killed 84 people and caused some of the highest water levels ever recorded. In some places the water reached as high as 40 feet above normal. Take a look at the two videos I’ve embedded below to see how these events compare.

According to Dupigny-Giroux, Irene and the Great Flood were intense versions of weather systems that periodically affect the state each decade. Autumnal flooding is relatively common in Vermont.  In fact, during two to three years each decade, the state has been hit by flooding related to a hurricane or its remnant. According to Dupigny-Giroux these events resulted in better flood control plans and wiser development on flood plains. These changes seem to have worked. Compare the number of deaths in 1927 with those from Irene. Despite a similar scale of flooding, new policies and better infrastructure, seem to have done a better job at protecting Vermonter’s lives.

But the damage from Irene demonstrates that these changes have not gone far enough and that lessons still need to be learned. One of the most shocking events during the flood was the destruction of a propane depot built on the banks of the Ottauquechee River in Woodstock. Entirely washed away, people down stream watched as large and small propane tanks floated down the river. Similarly, in nearby West Lebanon, New Hampshire, a shopping plaza located just downstream from the junction of the Connecticut and White Rivers was severely damaged. Much like the propane depot, these stores were built on a known flood plain, just a couple dozen feet from the Connecticut River’s banks.

Some infrastructure needs to be located near rivers. Indeed, Irene destroyed a number of covered bridges, century-old homes and buildings that had survived the past severe storms. Many of these buildings were located beside the river out of necessity.  Bridges were required to cross the river, homes (and even towns) needed the river for water and transportation, and mills harnessed the river’s power. These places were built near the water for a purpose.

But a propane depot and a mall are not the same as an old mill or covered bridge. The location of these late-twentieth-century developments is illustrative of a lack of adequate planning by both government and business to account for Vermont’s and New Hampshire’s climate and flooding history. Their location reflects a prioritization of business interests focused more on profits than the needs of local residents and the environment.  Indeed, the developers who own the flooded plaza in West Lebanon have sued the municipality over its desire to more tightly regulate development on the flood plain after Irene.

The storm that hit Nova Scotia was less significant than Irene. Much of the flooding is being blamed on global warming and climate change.  This explanation holds much truth.  Warmer oceans mean greater likelihood of severe storms in the northeast – much like hurricanes Juan and Irene. Glacial melting bring higher tides, expanding the extent of many flood plains.

It would be wrong, however, to suggest that this was solely the cause of the flooding in Truro. RCMP Staff Sergeant John Berry got his history right when last month he told the Halifax Chronicle Herald:  “We suffer from flooding… on a regular basis. And all those roads that are normally flooded out are, of course, the first ones to go again.” According to the CBC, this is the third time this decade that the Nova Scotia town has flooded.

Geography and town planning play an important role in Truro’s history of flooding. In Nova Scotia, almost all of the good farmland lies near (and even below) sea level, often behind dykes. Ever since the French arrived in the early seventeenth century, the European residents of Acadia and Nova Scotia have farmed land reclaimed from the sea. Before the dykes were built, this land was underwater during high tide.

Truro has a number of geographic factors that lead to flooding. Located at the top of the Bay of Fundy, Truro is confronted with a low-lying topography, extremely high tides, and two rivers flowing into the Minas Basin. In a strong northeaster, the storm surge (sea-level rise caused by low pressure) and heavy rain can prevent the rivers from draining, causing the run-off to both build-up behind the dyke and also flow over their tops.

Natural Resources Canada has used Airborne Laser Terrain Mapper (ALTM) technology to better understand Truro’s history of flooding and to predict flood patterns. The images below, taken from the project’s website demonstrate how flooding affects this Nova Scotian town. They depict Truro under normal conditions, under a perigean spring tide (the highest of possible tides), and during the Saxby Gale in 1869. The Saxby Gale brought some of the worst flooding in Nova Scotia’s history. On October 5th a storm travelled up the Bay of Fundy, hitting the top of the Bay with a two-metre storm surge. Flooding was so extensive that it nearly severed Nova Scotia from New Brunswick in the Tantramar Marshes.

Truro under Normal Conditions

Truro during Perigean Spring Tide

Truro during the Saxby Gale

Notice in these images that much like in Vermont and New Hampshire, some of Truro’s late-twentieth century development (like the malls) has been built on a known flood plain.

Floods like those brought by Irene and Leslie demonstrate the importance of understanding and learning from the past. Irene was far more damaging in Vermont than Leslie was in Nova Scotia, but each of these events teaches us important lessons.  Both events provide good examples of the needless damage that occurs when the local environment and its history is not seriously taken into consideration.

As people rebuild and reflect on these disasters, it is important to look to the past.  Not only should we ask ourselves, in what ways were these events similar to what has taken place before?  And what lessons should developers, regulators, and politicians take away from these events? But as Active Historians, policy makers and concerned members of the public, I think that we should also ask ourselves why the lessons from the past were not heeded.  Why was that propane depot built on the banks of the Ottauquechee River in Woodstock, Vermont? Why were Truro businesses built in an area prone to flooding? Who approved these developments, and why?

If we are to truly focus on the importance of the past as a tool for crafting future policies and development, we must also examine the instances when the lessons of the past have not been learned. The history of flooding, although often caused by nature, is seldom a “natural disaster.” Rather these events are caused by our failure to learn from historical precedents. With foresight, planning, and greater attention to environmental history, much of the damage brought about by floods can be mitigated.

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Author’s Note: I couldn’t fit this in but if you are interested in flood plains and municipal planning, consider consulting the Environmental History of Kentville, Nova Scotia produced in 2010 by the students taking Canadian Environmental History at Acadia University. The section on the history of the Kentville flood plain does an excellent job at encapsulating the complexities and ambiguities of flood plain management.

Thomas Peace is a SSHRC Postdoctoral Fellow in Native American Studies at Dartmouth College and a member of the ActiveHistory.ca editorial collective.

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