Magic Mountain Dam (2 miles from the West River in South Londonderry) was constructed in the 1980s to plug up Thompsonburg Brook and create a pond for snowmaking at Magic Mountain Ski Area. The dam was removed in 2020 thanks to the Connecticut River Conservancy and the U.S. Fish and Wildlife Service, providing fish passage in the watershed. Removal of the small dam opened up 5 miles of upland stream for trout habitat.
The benefits of dam removal for Species of Greatest Conservation Need (SGCN), in
particular brook trout, include: Improved access to available riverine aquatic habitat and food resources; avoidance of predator interactions; ability to recolonize upstream reaches after catastrophic events such as floods; ability to seek thermal refuge during warm summer months; promotion of genetic diversity; improved lotic (flowing water) habitats; and increased sediment and nutrient transport.