Flat Creek Cove is more than a ton lighter in trash, thanks to a weekend cleanup that involved 212 volunteers. But early-week rains could create another mess for the 6-mile waterway that cuts through Gainesville and unincorporated Hall County, highlighting the creek’s ongoing stormwater problems. “We need the rain, we definitely need the water, for sure, but we don’t like the pollutants that come with it,” said Brian Wiley, Gainesville’s environmental monitoring coordinator, on Monday.