Before a litter trap was installed on Flat Creek in December, a cleanup of the long-troubled urban waterway meant serious work. “It used to be, after a rain you’d … almost be able to walk across (the creek) with all the floating cups, cans and garbage,” said Diane Rothberg, who lives off the creek as it empties into Lake Lanier in West Hall County. But there’s still trash, mostly lingering from before the trap was installed off Old Flowery Branch Road in Gainesville, and “all the rain we had over the winter … just washed some of the garbage farther down the creek,” she said.