More floods like those in 2011 are expected; preparation is urged
The extreme flooding that hit Lake Champlain twice in 2011, causing millions of dollars in damage in New York, Vermont and Quebec, will become more likely due to ongoing climate change and work must be done now to prepare, a report issued by the Vermont-based Lake Champlain Basin Program says.
“Many of the recommendations serve the dual purpose of protecting life and property along tributary corridors, the Richelieu River and Lake Champlain’s shoreline, and also limiting environmental damage from future floods,” said Bill Howland, program manager for the basin that includes the two states and the Canadian province. “We have identified critical information data gaps for the jurisdictions to consider.”
The report stems from record flooding that first hit the lake for two months in the spring of 2011, fueled by melting snows and heavy spring rains. The 125-mile lake hit an all-time record high May 6, when it covered an additional 66 square miles, inundating communities from Whitehall in northern Washington County all the way up the lake to southern Quebec. Evacuations of people who lived in flooded areas just in New York cost the federal government nearly $10 million in disaster area funding.
Then in August, Tropical Storm Irene hit parts of the region with flash flooding causing by downpours that overwhelmed rivers and streams, again washing out homes, roads and bridges. Because of the floods, farmers had reduced growing seasons, ferry traffic around the lake was disrupted and the Champlain Canal opened a month later than normal. Between both disasters, emergency aid spending totaled more than $250 million in the U.S and Canada.
More such floods — and the bills that follow — are likely as the climate continues changing in ways that make future floods more likely. “Climatologists believe increased annual precipitation and flooding will continue to be a consequence of climate change,” according to the report.
Since 1970, it has been getting more rainy around the lake, with three additional inches of rain now falling each year; consequently, the lake is about 1.5 feet higher. During that period, average temperatures have climbed by about 2.2 degrees, meaning the lake is much less likely to freeze. And tropical storms in the region are expected to become more common as storms take a more northerly route as Atlantic temperatures rise, according to the report.
Emissions of greenhouse gases from combustion of fossil fuels — which an international scientific consensus blames for ongoing man-made climate change — are not being significantly reduced, so planners around Lake Champlain must prepare ways for people to adapt their property, roads and infrastructure, like drinking water and sewage plants, to a changing environment, the report found.
Part of that adaptation, the report recommended, would be to remove development from natural floodplains — around both the lake and the rivers and streams that feed it — so those areas would function more fully in future flooding.
A scientist from Paul Smith’s College in Saranac Lake who studies Lake Champlain said the report reveals the changing future of the lake and possible steps to help protect property, people and the lake itself.
“This report essentially treats the extreme weather events of the last several years as “teachable moments.” Rather than simply enduring the recent floods, it is also important to learn as much as possible from them because the science, the models, and prudent common sense all suggest that there could well be more of this sort of thing to come in a warming future,” said Curt Stager, a professor of natural sciences.
The state Department of Environmental Conservation had no comment about the report’s findings and recommendations.
Federal flood insurance may have played a role in the amount of damage. The report said the Natural Flood Insurance Program, which provides insurance to homes and businesses for flood damage, has failed to limit development in the areas around the lake most at risk of flooding.
“Although National Flood Insurance Program guidelines are designed to reduce the costs of repairing flood damage to insured structures within the 100-year-flood zone, they are not robust enough to protect floodplains from further encroachment in these critical zones, particularly along tributaries in the upper elevations with highly erodible soils. The cost of the recent floods is evidence that the national standards are inadequate,” the report found.
The report also recommended that New York, Vermont and Quebec create flood resilience offices for the lake.