The Future of Farming in a Wetter Vermont
Written onDecember 01 , 2011
A sobering aspect of both the spring flooding of Lake Champlain and the devastating flood following Tropical Storm Irene is that for climate scientists working in Vermont, neither event was all that surprising.
Dr. Lesley-Ann Dupigny-Giroux is an associate professor in the geography department at the University of Vermont and serves as the state climatologist. When asked if the events of August 28 were surprising to her, she said, “No, from three perspectives.” First, Vermont has seen similar events in the past; the storms of 1927 and 1938 followed similar paths. Second, from the perspective of precipitation amounts, we have had more rain in single storms before. And finally, from a geographic point of view, because of our topography. “Whenever you get a storm track parallel to those [north/south mountain] barriers, you will get exactly what we had this time, and exactly what we had in 1938,” Dupigny-Giroux says, “so I wouldn’t be hugely surprised if something like that happened again.”
Although scientists are notoriously cautious in making predictions, there is a plethora of data available that make clear these events are consistent with climate trends. Dr. Alan Betts is an independent atmospheric researcher working in Vermont who recently wrote a paper on climate change in our state that is available on the Agency of Natural Resources website. Climate change predictions are usually expressed in terms of a “high emissions scenario,” which assumes things continue as they are now, or a “low emissions scenario,” which envisions significant progress toward reducing CO2 released through the burning of fossil fuels. Under the high emissions scenario, Betts’ report predicts that by the end of the century, we will see 15 percent more precipitation in winter, 10 percent in the spring, 5 percent in the fall, and no change in the summer. We will also see an increase in heavy precipitation, more winter rain (as opposed to snow), earlier ice breakup, early spring snow melt, and more runoff from heavier summer rainfall. (Although there will be no change in overall summer precipitation, the rains that do fall will be heavier.) These predictions reflect observed trends: over the past 50 years, the amount of rain falling during very heavy storms in the Northeast has increased 67 percent.
Although storms are likely to bring more rain, warmer temperatures will cause more evaporation, so we will also see more droughts in summer. These unpredictable swings between drought and flood conditions are perhaps the surest prediction we have for what Vermont farmers will have to contend with in the coming years.
Many Vermont farmers have already seen the impact of climate change: earlier last frosts and later first frosts (extending the growing season for frost-sensitive plants by two weeks), more severe storms, more and longer droughts, and extreme variability in terms of when and where rain will fall. “We started noticing it over the last four or five years,” says Jack Manix, a vegetable and berry farmer in Dummerston. “The trend has been for extremes. Last year was one of the driest; this year was one of the wettest. The rains seem more torrential. The highs are higher and the lows are lower.” On the upside, Manix always used to plant a few “Hail Mary” crops for fall harvest—for example, beans he’d plant in late summer with the hope of harvesting them before the first frost but never knowing if they’d make it. “Our ‘Hail Mary’ crops are becoming our regular crops,” Manix chuckles, noting that last frosts have moved from late September to around Columbus Day. In fact, most of Vermont used to be in USDA Hardiness Zone 4; now, most of the state is classed as Zone 5.
To respond to anticipated drought, Manix has put in drip irrigation systems, which he didn’t need to use this year but which might come in handy soon. He’s also invested heavily in greenhouse construction. Greenhouses can help mitigate the impact of sudden heavy rainfall on exposed crops. On the other hand, greenhouses themselves can be damaged by heavy, wet winter snow so they have to be built to withstand these conditions. If Manix knows snow is predicted, he’ll start heating the greenhouses early to help melt that snow. He also has made swales between the greenhouses to catch and channel rainfall that runs off the sides. That water is then stored in a catch basin for later irrigation needs. “I’ve been complaining for years that we don’t have a major water source nearby the farm,” Manix says, “but I’ve quit complaining now!”
The Intervale has historically flooded, at times severely. In his account of the 1927 flood, Luther B. Johnson wrote, “The Intervale lands were badly cut and strewn with wreckage, including many trees torn up. From there to the outlet and for a considerable distance onto the lake surface the debris brought down by the Winooski, which had not already lodged along its course, scattered far and wide as the force of the flood spent itself where it could no longer do harm.”
At 7:30 a.m. on August 29, 2011, Thomas Case, who farms the 20-acre Arethusa Farm in the Intervale, had been watching the online hydrological graph of the river level at Essex Junction. He had been thinking this was going to be a “regular flood” that he’d seen many times before, in which the water comes in slowly through the swampy back area of the Intervale and gradually spreads, flooding his own fields last, if at all. He and some volunteers were in the fields, trying to prioritize which crops to harvest and which equipment to move. He has some of the highest land in the Intervale but within hours that land was surrounded by water.
“At that point,” he remembers, “we made sure we got our tractors out. As we were standing there, the water started filling up around our feet. We realized, we needed to get out of there. We were driving through a foot or two of water on the tractor, making big wakes. The thing that was different was the volume of water, and the speed that it was coming over the bank. You could see the water coming; it was like rapids as it went across the land. It was the opposite of what we usually see. There were currents going around the Intervale as the water flowed in….”
When it was over, and the water finally receded, the silt that the floodwaters dumped on the fields created little dunes and ravines so that the field resembled a beach. Case and his business partner Ben Dana ended up losing almost everything. Case is currently looking for work and contemplating the future, after a summer of constantly reacting to what the weather had brought and seeing his best laid plans disappearing along with everything else that got swept away in the floods. He is considering letting go of some lower land he has in the Intervale and possibly looking for some additional land outside the flood zone but still close to Burlington, which he could use to hedge his bets against more floods like Irene.
Travis Marcotte, the Intervale’s executive director, says that as far as he knows, none of the Intervale farmers are planning to leave, although many of them have some tough decisions ahead. “This isn’t the first flood that’s weighing on their minds in terms of the viability of farming here. It’s a somewhat constrained environment to farm within, between the flood potential and the archeological issues.” (The land was farmed for centuries by the Abenaki, so care must be taken to avoid damaging potentially important archeological resources.) “But you balance that with some of the best soils in the state and the proximity to markets…. It’s an ongoing issue that you have to balance out.”
Marcotte says the organization had been working on a draft flood response plan for several years, and although this was the first year it had to be executed, in many respects it worked well. People mobilized quickly, equipment was moved, and potentially contaminating materials were safely stored. Going forward, the question is how to mitigate the risk of future floods for the farmers. “We’re not considering mechanically altering the landscape,” Marcotte says. ”Part of the benefit has been the natural movement of the river, depositing all that great soil, but we’re considering building in a little more riparian buffer.” That means increasing the size of the buffer zone between the river and cultivated fields and adding diverse plants and trees that can absorb and slow down floodwaters. The Intervale also runs a nursery growing native trees, and Marcotte would like to help get these trees planted in other riparian zones in the region that need restoration for both flood control and wildlife habitat.
He is also looking into the possibility of helping Intervale farmers buy additional land on higher ground. “It would be really cool to replicate the collective farmer model that is the Intervale…that allows the heavily used tractors and other equipment to be shared. Why not replicate that somewhere else?” Other ideas include looking carefully at insurance options that would support farming in flood plains, perhaps through an insurance pool, and helping farmers think about which crops to plant at which times to best cope with flood risks.
Elsewhere in the state, farmers with fields prone to flooding are being advised to plant hay, straw, perennials, or crops used for biofuels in those fields rather than crops for immediate human consumption. Several farmers in Vermont are also experimenting with a crop that can tolerate very wet conditions, and that may, in fact, provide a method for protecting land downstream from flood damage—paddy rice.
Over the past six years Takeshi and Linda Akaogi in Westminster have trialed more than a hundred varieties of rice selected for tolerance to cold and short growing seasons. The Akaogis report that their rice did very well this year, suffering no ill effects due to the wet spring and fall. A rice paddy is built to hold 6 to 8 inches of water during the growing season but can hold up to 12 inches in the event of a flood, without damaging the crop. A paddy-rice system also includes a holding pond, which provides a reservoir that can be 5 to 6 feet deep. In the event of an anticipated flood, the holding pond can be drained in advance so as to capture additional floodwater, which later can be used for irrigation on the farm. The Akaogis emphasize that no existing wetlands should be damaged to construct rice paddies. Instead, marginal agricultural land that is often too wet for other crops can be used.
A recent report on the likely effects of climate change on agriculture in the Northeast, by David Wolfe of the Cornell Horticulture Department, predicts “more field flooding…more soil compaction, and possible crop loss due to lack of oxygen for roots and disease problems associated with wet conditions.” This, combined with the longer growing season we are already experiencing, would suggest that rice may not only be a viable crop for the Northeast, with potential yields of approximately two tons per acre, but a means to utilize floodprone areas, particularly around Lake Champlain, where soils are rich in the clay needed to construct the ponds and paddies that will hold water. The Akaogis note that rice paddies, as “constructed wetlands,” provide some of the other ecosystem services that natural wetlands provide, such as water filtration and groundwater recharge. They also provide habitat for a wide range of wetland species, including frogs, salamanders, dragonflies, turtles, snakes, and birds, all of which have increased in numbers at the Akaogi Farm since their rice growing began.
Thomas Case of Arethusa Farm points out that in the aftermath of Irene people are talking about food and agriculture at all levels in the state. “That’s exciting, that’s one of the positive things about this flood, that these discussions are happening. I hope that momentum continues over the next couple of years and onward.” And Travis Marcotte remarks, “I think the Intervale farmers can serve almost as a working laboratory where you could bring rigorous research and scientific evidence together with the practical solutions Vermont farmers are known for…to come up with solutions that would work for us.”
If that kind of effective collaboration results, perhaps 2011 will be a watershed year not just for extreme weather events but for renewed attention to all the ways that watersheds and farmland can best be managed for resiliency and health in the years ahead.