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Flood control system facing costly repairs

By DAVID MELSON - dmelson@t-g.com
Posted 12/17/22

Costly but unavoidable repairs of Shelbyville’s downtown flood control system are becoming a must, City Council members were told at a study session Tuesday.

Consulting engineer Will Owen …

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Flood control system facing costly repairs

Costly but unavoidable repairs of Shelbyville’s downtown flood control system are becoming a must, City Council members were told at a study session Tuesday.
Consulting engineer Will Owen explained the basics of the system to the council and Mayor Randy Carroll.
•The flume, consisting of three tubes – 2,300, 2,700 and 3,100 feet long.
•Corrugated metal pipe cross sections.
•The levee, including the steep barrier-type hill, comprising the area including the floodgate.
•Flood pumps atop the levee.
“If there was no levee, floodwaters would cover primarily commercial properties,” Owen said. “A large part of downtown is protected by the levee.”
Part of the pumps’ purpose is to send excess water to the holding area near the North Cannon Boulevard-West Jackson Street intersection and into Duck River west of downtown, Owen said,
Aging system
The system was constructed in 1961-62 and is in need of major upgrades if not outright rebuilding, Owen said. He said visiting engineers have told him they’ve never seen a system similar to Shelbyville’s – and they weren’t being complimentary.
One concern is the size of the pumps. The early 1960s council chose to purchase pumps smaller than engineers intended for the system, Owen said. Age has taken its toll on the pumps; today one operates at 75% capacity and the others at 50%. Parts are hard to obtain as the pumps are obsolete. The council was told the pumps were manufactured by Allis Chalmers, best known for farm tractors, rather than a specialized manufacturer.
“Replacement parts are almost impossible to find,” Owen said.
Two of those pumps were completely inoperable at times during the heavy rains of September and October, Owen said.
But a even greater concern is the danger to members of Shelbyville Fire Department, which oversees and operates the pumps, and Shelbyville Public Works employees. Carroll said his main priority is safety to workers first, then the public.
The need for pump use and raising of the floodgate is determined by watching a manhole at Fisherman’s Park. When water reaches that point, the pumps are turned on manually.
The pumps are energized by 2,300 volts of electricity wired into them. Firefighters must walk across the top of the steep, narrow levee and across a catwalk to start the pumps. During one of last fall’s rains firefighters avoided electrical shock dur to visual observance during daylight, Owen said. Night use could have resulted in tragedy.
The floodgate does have a switch which sometimes doesn’t work, Fire Chief Matt Doak said. It can be manually raised.
Three flume failures have occurred in the past eight years, necessitating the replacement of approximately 1,000 feet of pipe. Owen said.
Current needs
Owen described three current primary needs:
•Replacing the three pumps and the structures they sit atop. Cost is estimated at $1 million each. The council was urged to purchase pumps with the proper capacity for a much larger city than the Shelbyville of 60 years, keeping expected high growth in mind.
•Relining the portion of the flume directly underneath the levee, utilizing much better materials than those originally used.
“If it fails, the levee fails and (flood) protection is no longer there,” Owen said.
•Upgrading the flume’s entry point at the Madison Street-North Brittain Street intersection. Owen said it’s good that the former drug store next to the flume, now occupied by a ministry for the homeless, is “sparsely” used and urged that no new development be allowed above or near the flume. He noted that the city hasn’t allowed development in those areas since the 1980s.
If possible, several other areas of the flume should be replaced or rehabilitated, Owen said.
Replacement of the pumps alone with new, larger units would cost an estimated $1 million apiece, including modern controls and automation equipment.
Much further steps, as in totally repairing the current flood control system, could cost $40 million, Feldhaus said.
“Maybe the best thing would be to let a disaster happen,” Feldhaus said. “Then FEMA (the Federal Emergency Management Agency) could come up and help us after the fact.”
“There’s a reason the system doesn’t work – because it was built on federal money.”
Feldhaus explained the original urban renewal program of the early 1960s was used to renovate what had been a large, “blighted” area of older, rundown structures just north of downtown, many which were flood-prone.
“It’s not a blighted area anymore,” Feldhaus said.
Possible goals
Feldhaus suggested a long-term goal for Shelbyville could be purchasing as much of the land as possible in areas originally threatened before the flood control system existed and dismantling any buildings in those areas.
A particular concern of Feldhaus is a project proposed just off Highway 82 Bypass downtown, which may include an underground parking garage. Feldhaus wants to ensure any garage doesn’t flood.
“What could break the system?” council member Marilyn Ewing asked.
“The levee is stable, there are no structural concerns,” Owen said. “If the Sept. 20 rain event had occurred with all the pumps inoperable, then Lane Parkway and North Cannon Boulevard would have been flooded.”
Even with pumps working, water was knee-deep on Lane Parkway in front of police headquarters and “coming in the front door” of Shelbyville Fire Department, Doak said.
The city is discussing possibly studying improving or moving city buildings. Mention was made of moving the police and fire departments to another area of the city away from the flume. A parking lot between the police and fire departments fell in when a portion of the flume collapsed, taking a police patrol car with it.
Carroll asked if engineers had looked at new ways to get water to Duck River. Public Works Director Buck Vallad said consideration was given to “opening up” the river, but it would be cost-prohibitive and involve buying properties and relocating businesses.
“All the past repairs are the result of failures,” Owen said. “The city should be proactive rather than reactive.”
Doak said one engineering firm he’s talked to told him they could work with the existing flume. An entire flume replacement can be done independently from the pumps, Owen said.
Consultants discussed several funding sources available to the city, mostly various types of federal grants.
Action urged
City Manager Scott Collins asked that discussion of the city’s drainage problems be placed on the council’s January agenda.
“I’ve been here three months and we’ve talked and talked and talked about it,” Collins said. “This could be a definitive action.”
“This has been going on for 10 to 20 years,” Carroll said. “Someone should have done something before now. I’m not going to point any fingers…It’s time to make a move.”
Vallad said he’s looked into using renting temporary portable pumps if an emergency arises. Those pumps run off diesel generators, Vallad said.

He said installing this type of generator permanently would not be cost-effective because they cost $25.000 per month even if not used.