Tucked away in the woods with trees overhanging it and morning sunlight peeking through the fall foliage, Flat Creek looks like it belongs in a storybook — or at least as the bubbling focal point of a pristine park. It’s hard to imagine that farther upstream the creek flows through some of Hall County’s most urbanized areas, with industries, businesses and homes crowding either side. Through the years, Flat Creek has suffered from pollution and contamination brought about by everything from litter to sewage spills, leading to a designation as an “impaired” waterway.