A water main break that flooded downtown Fort Worth on Aug. 17 did more than just wreak havoc on West Lancaster Avenue. Chlorinated tap water released during the break was also responsible for a fish kill in the Trinity River. 

City workers used kayaks and nets to remove dead fish from the river Friday, focusing on the area near downtown’s Panther Island Pavilion. High concentrations of chlorine is toxic to fish and can quickly damage their sensitive gills.

Mary Gugliuzza, a spokesperson for Fort Worth’s water department, said the city discovered the fish kill Thursday and immediately reported it to the Texas Commission on Environmental Quality and Texas Parks and Wildlife, as required by law. 

Any time there’s a main break, there’s a discharge of chlorinated water because all potable water contains chlorine to make it safe for drinking, Gugliuzza said. Typically, crews throw dechlorination tablets on the ground near a main break and allow water to run over it as it enters the storm drain system, she added. 

Crews remove dead fish from the Trinity River near Panther Island Pavilion on Aug. 18, 2023. A downtown water main break led to the fish kill, city officials said. (Emily Wolf | Fort Worth Report)

“However, in this case, with the size of this break, dechlor would not have done any good,” she said. “It was moving so swiftly and there was such a volume that it would not have served a purpose. I don’t know if we would have had enough for the volume of water.” 

The 30-inch main broke in the early hours of Aug. 17 and caused road shutdowns on Lancaster Avenue throughout Thursday. After a full day of repairs, the water line is back in service. Parts of Lancaster Avenue remained closed Friday as crews fixed parts of the street damaged by the break. 

The city doesn’t yet have a count of how many fish were killed. Staff are currently picking up the fish and classifying them by species — a process that could take several days, although there is no clear timeline for completion, Gugliuzza said. Fort Worth shouldn’t face a fine from state regulatory agencies because staff reported the incident within 24 hours, she added. 

Fort Worth is facing a surge of water main breaks this summer, with crews responding to about four breaks per day over the past month. City officials blame the increase on an aging cast iron pipe system under pressure from scorching summer heat, dry ground and increased demand for water. Most main breaks are much smaller than the Lancaster break and don’t cause fish kills, Gugliuzza said. 

Because the main break occurred so close to a body of water, city staff were on the lookout for dead fish shortly after the incident, Gugliuzza said. 

“That is an unintended consequence because the water is going into the storm drain system, which drains into the nearest waterway,” she said. 

Tarrant Regional Water District staff regularly conduct water quality tests on the Trinity River, said water district spokesperson Matt Oliver. The agency’s results on Friday were consistent with previous tests and did not find anything harmful to human health or safety, he said. 

Staff at TC Paddlesports, a business that rents kayaks and canoes to visitors at Panther Island Pavilion, began spotting dead fish in the Trinity late Thursday afternoon. Teresa Patterson, who runs TC Paddlesports and serves as paddle trail manager for the nonprofit Trinity Coalition, snapped photos of fish as they rose to the surface and reported the issue to the water district. 

A downtown water main break led to a fish kill on Aug. 17, 2023, city officials said. (Emily Wolf | Fort Worth Report)

Patterson suspects more fish were killed by the main break because the Clear Fork of the Trinity River is a “low flow” part of the river, meaning that a smaller volume of water passes through it during the dry season. 

“Any large amount of chlorinated water is going to have an outsize impact on the wildlife there because there’s not as much water to dilute it,” Patterson said. “If it was in a larger water body, a bigger lake or river with more flow to it, it has a better chance of diluting.” 

Kayakers were still able to paddle on the river Friday after water district officials assured Patterson the water was safe for humans. Her staff advised customers to use a nearby shower to cool off rather than dipping into the river as they typically would, Patterson said. 

Haley Samsel is the environmental reporter for the Fort Worth Report. You can reach them at haley.samsel@fortworthreport.org.

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Haley Samsel is the environmental reporter for the Fort Worth Report. You can reach them at haley.samsel@fortworthreport.org. Her coverage is made possible by a grant from the Marilyn Brachman Hoffman...