A kinked pipe, a tough balloon and a contractor kept sewage at bay at the bottom of the 30-foot sinkhole at the intersection of Park Drive and 23rd Street. Floodwaters carrying debris and items such as wooden walking bridges into the La Crosse River Marsh also picked up about 150 gallons of sewage on Thursday.
That’s equal to the capacity of a large 4-foot long fish tank.
“We’re pretty fortunate compared to a lot of communities,” said Jared Greeno, wastewater treatment general superintendent, noting the severe problems in Arcadia.
“The marsh is what saves the city of La Crosse,” he said, explaining that it acts like a large retention pond during flood events.
The blow out of a retention pond at the back of the Forest Hills Golf Course let loose a wall of water that washed away two bridges that were near the access to Hixon Forest, said Steve Carlyon, director of La Crosse Parks, Recreation and Forestry.
“They’re gone. They’re somewhere in the marsh,” Carlyon said.
“We’ve got crews going down to see if we can find them,” he said. “We found part of one of the bridges — it didn’t make it all the way to the marsh, so we’re pulling that stuff out.”
With the marsh also overflowing into the La Crosse River, Carlyon said, the bridges could be anywhere.
“Your guess as good as mine where it finally ended up,” he said.
While the parks department is dealing with major damage at the golf course and elsewhere, there are a number of much smaller sinkholes to address around town.
Greeno said the treatment plant weathered the storm well. The biggest impact at the plant on Isle la Plume was an influx of rocks washing into the sanitary sewer system. In the initial filtering stage, plant staff removed two wheelbarrows of rocks.
Because of the sewage overflow, the city was required to send out public notice. It tells the story of early Thursday morning after 6.4 inches of rain had fallen on La Crosse from 6 p.m. Wednesday to 4 a.m. Thursday. The storm water overflow at Park Drive and 23rd Street washed away a bank and under the street causing the hole and the collapse of the storm sewer, water main and sanitary sewer.
“When the sanitary sewer failed/broke off, flow was plugged off and eventually an inflatable plug was installed to stop sewage from leaving the pipe,” the report says.
The city has a collection of inflatable plugs that Greeno likened to balloons made of “real tough rubber.” They are inflated with an air compressor and come in different sizes. An 8-inch balloon was inserted into the pipe that had kinked and broke off.
“I can’t thank the contractor enough,” Greeno said. Gerke Excavation began repairing the location Thursday afternoon and by 5:30 a.m. Friday, the “new sanitary sewer main was installed flow resumed as normal.”