GREENTOWN — The massive pile of logs near Jerome probably started taking shape when the 1998 tornado ripped through eastern Howard County.

By the time contractors started attaching cables to the logs and hauling them out of the logjam with an excavator this winter, the pile of logs stretched about 50 yards, blocking the breadth of the Wildcat Creek.

“It was probably the biggest logjam in the state,” said Bill Young, construction supervisor with Larwill-based CRI Construction.

Forced wide by the logjam, the water eroded both the south and north banks of the Wildcat. This created a cove to the south and tore out part of a hillside to the north. Properties on the northern hillside were threatened.

That’s why big logs — around 30 feet long and 3 feet in diameter — are now sticking out of the creek bank on the southern bank.

The logjam itself has become an experiment in erosion control.

Once stuck in midstream, the logs have become the anchors for a 500-foot long shelf, which will stick out 15 feet into the stream.

And the Wildcat, now freed of the logjam, is running more or less within its banks. The channel the logjam-stoppered stream carved between a sandbar and the north bank is now drying out. Rushing waters are no longer carving out earth. The level of the stream is lower.

According to Young, using the logjam pile to construct an erosion-control shelf is something new to Indiana. The Jerome project, funded by the Indiana Department of Transportation as part of the U.S. 31 Kokomo Corridor project, is kind of an experiment.

“We’re kind of in an experimental stage, and everybody is interested in how [the shelf] will perform,” Young said.

Designed by Indianapolis engineering firm Butler, Fairman & Seufert, the shelf is also supposed to act as a fish habitat, offering aquatic life a place to get shade and a rest from the current’s tug.

Originally, the shelf was going to be 1,200 feet long, but there weren’t enough logs in the logjam to build something that big, CRI foreman Jeremiah Wittwer said.

Right now, workers are busy using metal stakes and cables to tie down the “anchor” logs.

Over the next week, they’ll use stakes and cables to lash other logs to the top of the anchor logs. Eventually, the structure will be about the same height as the surrounding creek bank, Wittwer explained.

So far, CRI has been on site for 38 days, and Wittwer said he expects about two or three more weeks of work before the project is finished.

Over time, more logs will probably make their way downstream to the shelf, and Wittwer said he expects some maintenance will have to be performed annually to keep the structure free of debris and logs.

The logs themselves are staked and lashed down in an attempt to keep the entire structure from floating whenever the water rises. The anchor logs are buried in the creek bank, with about half the length of each log under 5 or 6 feet of soil.

Wittwer emphasized that the structure isn’t supposed to float — it’s supposed to submerge when the water gets too high.

But without the logjam clogging the stream, the hope is that the low area south of Jerome will stop flooding as often as it currently does. Engineers worried the bottom land around County Road 180 South would slowly turn into a swamp if the dammed-up stream kept overflowing its banks.

With the shelf in place, engineers are now hoping there will at least be a five- to 10-year period when the Wildcat won’t be able to erode the creek bank.

What will the shelf look like down the road? It’s anyone’s guess. But Young said he hopes the erosion control becomes a permanent part of the landscape.

“I imagine you might see Mother Nature take over, and you might see trees growing out the top of it,” Young said.

• Scott Smith is a Kokomo Tribune staff writer. He may be reached at 765-454-8569 or via email at scott.smith@kokomotribune.com