Like a scene from “Dune,” a crater of sand and rubble appeared to be devouring a sewer manhole on a screen behind Waco City Council members last week.
“This is a bad day in a civil engineer’s life,” said Charles Leist, Waco infrastructure services director, presenting the latest sinkhole on an East Waco sewer main plagued by collapses.
The 42-inch sewer main runs the length of Martin Luther King Jr. Boulevard and past Highway 77 to Waco’s treatment plant. The portion currently under repair collapsed July 2025, 20 feet from the Union Pacific railroad. Since 2007, the line has collapsed three times, costing the city more than $6 million.
City workers got a clearer view of the damaged portion this month after gaining access through the damaged manhole. The results were not encouraging.
“It’s in terrible condition,” Leist said, and Lake Brazos may have to be drained to thoroughly inspect the rest of the main.
Repairs for the most recent failure are expected to cost $3 million to $3.5 million and wrap up in November. For now, sewage is being pumped around the affected section with an above-ground pipe snaking along MLK Jr. Boulevard.
The city offered businesses along the bypass pipe up to a $100,000 in compensation in June because of a fecal aroma emanating from it. The challenges of the current repair underscore the complexity of a long-term solution for the nearly 60-year-old sewer.
But the alternative, deferring maintenance on the rest of the main, could mean sewage in the Brazos River and disruptions to a main serving East Waco, China Spring and Bellmead.
“You got probably 30% of the flow that goes to the treatment plant coming down (the sewer) on that side of the river, and if that line fails, guess where it goes? It goes into the river,” said Wiley Stem, a former Waco city manager who oversaw repairs on the East Bank line during previous failures.
Because of the proximity of the collapse to the railroad, Union Pacific must grant permission for every phase of work, which began in March, Leist said.
That work is taking place in a pit 25 feet underground and less than 1,000 feet from Lake Brazos. The groundwater pressure from the impounded river is immense, constantly threatening to flood the pit with water, as it did during a repair on the same line in 2010.
Meanwhile, a tangle of existing utility lines around the collapse means heavy earthwork must be carried out with surgical precision. Fiber optic cable, power lines, TV and telecom cables criss-cross the area. “It’s like pickup sticks, I can’t move that stuff,” Leist said.
Complicating the work further, a portion of the line runs through storm drain culverts near Elm Avenue and Taylor Street.
The repair involves a new resin liner inserted into the existing main beneath the railroad. However, the liners will shrink the diameter of the pipe, reducing its capacity and adding yet another complication.
During high-use times, the change in diameter could cause a sewage backup. Preventing backups will mean constructing a separate relief line attached to the main, Leist said.
Union Pacific will not entertain discussion on the relief line until the city has engineering plans. Leist encouraged council members to support a full inspection of the sewer main from the collapsed section up to Brazos Park East, about 2.3 miles.
So far, inspections have been performed with remote cameras and sewer divers. That might not be adequate for fuller inspection of the main and the adjacent storm drains.
“Lowering (Lake Brazos) may be a sincere possibility to get all of those lines inspected in a timely fashion,” Leist said. “It’s very different with a diver looking through a mask … you can barely understand him, versus a group of engineers making safe entry into a structure like that.”
Within the next five to 10 years, depending on how much Waco grows, council members will need to consider redeveloping capacity along the entire main, he said, adding that the intersecting metal storm drains should be replaced as well.
Waco Mayor Jim Holmes hoped the city could avoid the nearly four-year repair sagas that attended both the previous sewer line collapses.
“We certainly don’t want that to be the case here, but we’re dealing with so many (complications),” Holmes said.
