Michele Gammal, the owner of Keeler Bay Marina in South Hero, said her husband and co-owner Michael is building an aquatic weed harvester this year. If it’s finished in time, the machine should help remove the plants that can choke their docks in the summer.
When neighbors in the small island town heard about the project, Michele Gammal said, they asked for help clearing the shorelines of their properties, too.
“It’s impacting the whole bay,” she said of the aquatic plant growth. “It’s not just us.”
Two organizations on the Lake Champlain Islands plan to study how land use in South Hero is impacting water quality in the town’s Keeler Bay. They also plan to develop projects that could limit the amount of nutrients and sediments entering the water.
Nutrients such as nitrogen and phosphorus are needed to grow any kind of plant, but when high levels of them enter a body of water they can lead to excessive growth.
Keeler Bay forms part of South Hero’s eastern shore within the northeast arm of Lake Champlain, a segment that has seen increasing concentrations of phosphorus over the past several decades, according to data from the Lake Champlain Basin Program.
The bay, a popular place for boating, fishing and other outdoor recreation activities, is important to South Hero’s economy. It’s also the source of drinking water for some 750 residents in the town of about 1,700, including the Gammals.
But there has never been a comprehensive study of Keeler Bay and the watershed that surrounds it, said Molly Varner, project manager at the Grand Isle County Natural Resources Conservation District. Her organization is leading the study along with the South Hero Land Trust, a group that also supports local conservation efforts.
“For such an integral body of water that’s part of the Islands,” Varner said, “it was really lacking any sort of systematic analysis of water quality and habitat stressors.”
According to Varner, planners aim to come away from the study with a report similar to a Lake Watershed Action Plan, which officials have developed for other Vermont bodies of water including Lake Elmore and Lake Eden in Lamoille County.
According to the state Agency of Natural Resources, these plans answer the questions: “What issues threaten the health of our lake the most?” and “What can we do about them?” They include a list of recommended projects sorted by priority level.
Varner noted that the state’s most recent (2020) Tactical Basin Plan for northern Lake Champlain called for further study of the impacts of stormwater runoff on Keeler Bay.
As part of the latest study, Varner said planners will use maps, field surveys and existing data on water quality to paint a more complete picture of the sources of runoff into the bay. She cited small streams, wetlands and private roads as some potential sources.
Planners will then develop 20 to 30 projects that would improve the bay’s water quality, with a focus on reducing the phosphorus going into the water, she said. From those, they’ll select a handful to partially design and line up for funding opportunities.
Projects could include planting trees along streams or the lakeshore, repairing failing culverts and constructing rain gardens or bioswales, Varner said. Work is set to begin this summer, funded by a roughly $40,000 grant from the Basin Program.
South Hero is a largely agricultural community, though the town’s two designated village centers, which have relatively dense development, border Keeler Bay.
Guy Maguire, programs director at the South Hero Land Trust, said that while phosphorus has accumulated in the bay’s watershed from decades of agricultural work, study planners are not looking to only blame farmers for water quality issues.
He pointed to data from the Basin Program showing that the amount of phosphorus entering Lake Champlain per square mile from agriculture is less than half the amount per square mile that enters the lake from developed land.
Varner said the invasive plant Eurasian watermilfoil, commonly called “milfoil,” has been a nuisance for people living and recreating around Keeler Bay. The feathery weed can make it unpleasant and difficult for people to swim or boat in the water, she said.
To be sure, she noted that the amount of plant growth is related to factors besides nutrient runoff, including the lake’s temperature and water level.
“The lake is higher this year so it’s not as bad,” reported Gammal, of the marina. But she said last summer — when the lake level was frequently below average — “was awful.”
Varner said there are occasional blue-green algae blooms in Keeler Bay as well, though they’re less frequent than in other parts of the northeast arm, such as Missisquoi Bay.
The organizations leading the study have no regulatory power, she noted, so planners are relying on cooperation from local landowners. They hosted an event at a farm in town July 7 to discuss local water quality, and about two dozen people came out.
“We want the assessment to be really community driven,” she said. “As we get further in the development of this assessment, we want people to say: ‘Hey, we’d love for you to assess our shoreline.’”
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