Tree roots caused two separate sewer overflows on Tuesday, Aug. 4, sending a combined 500 gallons of wastewater into Chattahoochee River tributaries in East Cobb. The spills mark at least the fourth and fifth root-caused overflows in the county in roughly two weeks, according to county records and our earlier reporting.

The first overflow hit at 2510 Regency Lake Drive, where the Cobb County Water System received notification at 7:09 a.m. Crews arrived to find manhole 491-E344 spilling with its lid secured, wastewater flowing into a tributary of Walden Creek. After clearing the blockage with a jet machine, workers found roots lodged in the sewer line. A CCTV inspection turned up no additional damage. The spill, estimated at 290 gallons, was stopped by 9:36 a.m.

Hours later, a second overflow surfaced at 3559 Sawmill Terrace NE. The Water System was notified at 12:53 p.m. and found manhole 101-F025 spilling across a 15-by-30-foot area before draining into a tributary of Piney Grove Creek. Crews set up a sewer bypass, then used a jet machine to remove roots and restore flow. That spill, estimated at 210 gallons, was stopped by 2:40 p.m.

Both sites are in East Cobb. Both creeks feed the Chattahoochee River watershed.

The incidents follow a pattern we reported Aug. 1: a 750-gallon root-caused spill into a Rubes Creek tributary near Bluff Stone Trace on July 30, which was itself the third such overflow in less than two weeks. The Marietta Daily Journal reported a 330-gallon overflow into a Sope Creek tributary in East Cobb on July 18.

The Cobb County Water System's CMOM press release index shows tree roots as a recurring cause of overflows across the county throughout 2025 and 2026. A prior overflow into a Piney Grove Creek tributary was recorded at 3464 Mark Hall Drive in April 2025.

Cobb County Water System Director Alicia Giddens is listed on both Aug. 4 press releases. The county has not issued a public statement addressing the pattern of root intrusions or any planned infrastructure response.

At both sites, crews applied lime to affected areas and posted spill signs. No fish kills were observed at either location.

Residents with questions can contact the Water System's System Maintenance Division at (770) 528-8731, Monday through Friday, 7 a.m. to 3:30 p.m.