Volunteers were scrambling Thursday to erect sandbag walls around downtown businesses and some homes as the rain-swollen Turkey River threatened to breach protective levees in northeast Iowa. Authorities said flooding already occurring in Clayton County’s Elkader and elsewhere is expected to worsen as the river was forecast to hit 27 feet this morning in Elkader. That’s 15 feet above flood stage and just shy of the record crest of more than 27.75 inches set in 2008. At more than 15 feet Thursday afternoon, the flooding of low-lying areas was “still manageable,” Elkader city administrator Jennifer Cowsert said. But, she added, if the level reaches the predicted 27 feet, it will flow over the levee. “When that happens, homes get water in them and the downtown businesses are affected,” Cowsert said. On Wednesday, officials scoffed at the initial prediction the river would crest at 25 feet this week, Cowsert said. When the estimate was bumped to 27 feet, Elkader’s fire chief drove upriver to inspect the conditions and came back worried, the administrator said. “He’s taking their prediction of 27 (feet) fairly seriously,” she said. After the 2008 flood, local officials launched an effort to buy up the most flood-prone property to keep homes from being built there. About 20 homes remain in the flood zone, Cowsert said. Even homes outside the zone can expect water in their basements, she said. Heavy rain Tuesday night and Wednesday morning killed at least one person and forced evacuations and school closures as it washed out roads.