by Kate Feiffer
Greta Thunberg was named Time magazine’s Person of the Year a day after a torrential rainstorm, the likes of which my Vineyard-raised husband says he has never seen, washed away a swatch of land under Lambert’s Cove Road. Thunberg, as readers of this newsletter likely know, is the young climate change activist who called out world leaders during her speech at a U.N. Climate Change Conference; Lambert’s Cove Road, as we also know, is not prone to washaways.
While the media has focused more on rising sea levels than the impact of torrential rainstorms, the drenchings and the potential for destructive rainstorms are worth noting. According to a 2014 National Climate Assessment Report, “The Northeast has experienced a greater recent increase in extreme precipitation than any other region in the United States.” The study states it is challenging to predict precipitation, however, “the frequency of heavy downpours is projected to continue to increase as the century progresses.”
“I do think we are getting a lot more rain, and it’s impacting the trails, and we need to keep that in mind for how we proceed in the future,” says Bill Bridwell, SMF Property Manager.
After a fierce rain storm in November 2018, Director of Felix Neck Wildlife Sanctuary Suzan Bellincampi wrote in the Vineyard Gazette: “We all know that water at its purest is simply H2O. Rain, however, is often adulterated with different particulates present in the air. In coastal area like ours, rain can have salt content, while other gases such as carbon dioxide, nitrogen dioxide, ammonium, and other particulates may be part of each drop.”
In a recent email exchange, I asked Bellincampi about the impact of extreme rainfall on conservation properties. She wrote back explaining that rainfall can lead to erosion, washouts, and can send sediments into ponds: “Sediments can include particles which can increase turbidity, and therefore water temperatures, when particulate matter heats up, decrease oxygen as warmer water holds less oxygen, leading to a decline of species that are sensitive to temperature.”
“We are trying to incorporate the impact of rainfall in the design of the trails, so that water in controlled somewhat,” says Bridwell. “As we’re cutting, we try to minimize the grade, meaning the incline of a trail, where possible, and cut at a tilt to make it so that water will go across, not straight down. And we’re putting in water bars and water breaks on areas that the erosion is already affecting the trails.” Bridwell explains that a water bar is a structure, usually a log or stone, that is above the grade of the trail, set across a trail to drain the water off to the side. Water breaks are like a step that is used to help slow water down on places where it may be rushing.
SMF Executive Director Adam Moore adds that SMF is working on preparing properties by paying greater attention to erosion potential on trails, and the need to manage water during storm events. “In the future, we will need to place a greater emphasis on the infrastructure supporting our conservation lands. For example, we need to make sure that our culverts are adequately sized and properly sited, so that roads will not wash away in a deluge. We need to pay greater attention to the designs of footbridges, and the slopes of trails, and the increasing maintenance needs of trails and access roads. This is an opportunity for us to set a new standard for conservation design.”