The livelihoods of thousands of farmers would be put at risk if the four lower Snake River dams are breached, a new study says. The study from the Pacific Northwest Waterways Association examined the economic, environmental and social justice impacts associated with breaching the dams, long targeted by environmental groups and tribes seeking endangered salmon recovery. Twelve counties — six in Washington, five in Idaho and one in Oregon — would be directly impacted by removal of the dams, according to the report, issued Aug. 13. About 7,644 farms in the affected area generate approximately $2 billion in annual sales.