Recent heavy rains have some residents sounding alarm bells about stormwater runoff from construction sites polluting Lake Lanier coves around Gainesville. “Sediment-laden stormwater flowing from poorly planned developments is one of the leading sources of water pollution in Georgia,” said Jason Ulseth, spokesman for the Chattahoochee Riverkeeper, a lead environmental advocacy group. “It clogs pipes and culverts, destroys aquatic ecosystems and fills in lakes and reservoirs.”