Sunday’s historic flood in Flowery Branch has produced another problem for the beleaguered South Hall city — a 200,000-gallon sewer spill into Flowery Branch Creek. City Manager Bill Andrew sent a statement this afternoon about the spill. "Due to extraordinary flooding ... the Flowery Branch Wastewater Treatment Plant was forced to shut off the pumps accepting untreated water from the sanitary sewer lines into the treatment plant," he said.