The Cobb County Water System provides clean, safe water to residents across the county through a partnership with the Cobb County-Marietta Water Authority. The county's water originates from the Chattahoochee River and Lake Allatoona and is treated at the James E. Quarles Treatment Plant in Marietta and the Hugh Wyckoff Treatment Plant in Acworth.
The Cobb County Water System also maintains a countywide wastewater collection and treatment program and a stormwater management program.