Full Breakdown
Massive Fish Kill on Atlanta’s Chattahoochee River Highlights Climate and Infrastructure Risks
5/26/2026, 5:01:26 AM
Event Overview
On Friday, May 22, the environmental nonprofit Chattahoochee Riverkeeper reported a massive fish die-off along a roughly 20-mile stretch of the Chattahoochee River downstream of Peachtree Creek in Fulton County. Executive Director Jason Ulseth discovered thousands of dead fish—including spotted bass, catfish, carp, shad and striped bass—some weighing 20-30 pounds, strewn on banks and caught in debris. A foul-smelling black film coated the shoreline, and litter such as condoms, menstrual products and wet wipes was observed in the water.
Contributing Factors: Drought, Stormwater, and Sewage Overflows
The die-off followed an intense thunderstorm on Wednesday, May 20 that dumped ? 3 inches of rain in an hour. Months of drought had reduced river flow to about 750 cubic feet per second, the minimum required by the U.S. Army Corps of Engineers. Warm runoff from heated pavement raised water temperature, decreasing dissolved-oxygen levels. Simultaneously, Atlanta’s combined sewer system and the eight-and-a-half-mile West Area Tunnel overflowed, releasing untreated sewage into Peachtree Creek, which then entered the river. Treated discharges from nearby wastewater facilities added further oxygen-depleting load.
Key Actors and Agencies
- Jason Ulseth – Executive Director, Chattahoochee Riverkeeper
- Lena Hardy – Spokesperson, City of Atlanta Department of Watershed Management (DWM)
- Greg Eyerly – Commissioner, Atlanta DWM
- Georgia Environmental Protection Division (EPD) and Georgia Department of Natural Resources (DNR) – State investigative partners
Data and Scale
- Fish mortality: Thousands, spanning at least 20 miles of river.
- Rainfall intensity: ~3 inches per hour on May 20.
- River flow: ~750 cfs (near-historic low).
- Species affected: Spotted bass, catfish, carp, shad, striped bass.
Ecological and Community Impact
The sudden loss of oxygen devastated aquatic life and raised concerns about downstream water quality, recreational use, and local economies that rely on the river’s natural appeal. Residents highlighted the river’s importance for tourism, especially with the upcoming World Cup, and expressed anxiety over repeated infrastructure failures.
Official Statements & Responses
City DWM spokesperson Lena Hardy emphasized that low river flow left little capacity to absorb the thermal and nutrient load from the storm, contributing to stress on aquatic organisms. Commissioner Greg Eyerly affirmed the department’s commitment to transparency and to protecting waterway health, noting that preliminary water-quality data show the tunnel operated within permitted standards, though full laboratory results remain pending. The Georgia EPD, DNR, and the Riverkeeper have launched coordinated sampling and analysis efforts.
Criticism, Legal History, & Local Concerns
Riverkeeper officials cited the presence of sewage-related litter as evidence of contamination, reviving litigation over Atlanta’s sewer overflows that dates back to the 1990s. Some community members praised past infrastructure upgrades but urged the city to “work a little harder” to prevent future incidents.
On-the-Ground Observations
Witnesses reported black, foul-smelling muck along the banks and fish floating in debris. Ulseth noted that the overflow structure associated with the West Area Tunnel directly feeds the affected river segment.
Conflicting Findings & Gaps
While Riverkeeper attributes the die-off to combined low flow, warm stormwater, and sewage overflows, DWM’s preliminary data suggest the tunnel’s discharge complied with existing permits. Comprehensive water-quality test results and a definitive attribution of each factor remain pending.
Verbatim Quotes
- “To see everything dead was just catastrophic,” — Jason Ulseth, Executive Director, Chattahoochee Riverkeeper
- “Once the heavy rainfall event hit the downtown urban core, the river had little buffer capacity to absorb nutrients and thermal loads. The flow on the Chattahoochee River was very low, while the urban streams were very high flowing into the river. The elevated temperature and time of day may have contributed to the creation of additional thermal load and stress on aquatic life,” — Lena Hardy, Spokesperson, Atlanta DWM
- “All of these combined factors just made for the perfect storm and caused the massive fish kill on the Chattahoochee,” — Jason Ulseth, Executive Director, Chattahoochee Riverkeeper
- “The problem Wednesday was that the tunnel completely filled and then overflowed directly into Peachtree Creek and the Chattahoochee River,” — Jason Ulseth, Executive Director, Chattahoochee Riverkeeper
- “All of the organic material of the river sucked it dry and essentially depleted all of the oxygen to where it looked like pretty much anything that swims was dead for well over 20 miles,” — Jason Ulseth, Executive Director, Chattahoochee Riverkeeper
- “Protecting the health of our waterways and the communities that depend on them remains one of our highest priorities,” — Greg Eyerly, Commissioner, Atlanta DWM
Next Steps
The Riverkeeper plans to meet with city officials on Thursday to discuss mitigation measures. Ongoing sampling by DWM, EPD, and DNR will inform a final report, and state regulators have indicated potential enforcement actions pending the results.
