How Salt Creek is being restored with dam gone

Water gushes over rocks and boulders as Salt Creek approaches Graue Mill in Oak Brook, an 1850s-era landmark where kernels of corn are still ground into cornmeal the old-fashioned way.

Near the site of what was a rumbling dam, a curved stone overlook now offers a view of the free-flowing creek and all the bubbles trailing across the surface. Showy plants will eventually grow further upland.

“We’re able to show that a natural river system can be just as beautiful as that waterfall feature that people were so accustomed to for so many years,” said Deanna Doohaluk, senior watershed project manager for the nonprofit DuPage River Salt Creek Workgroup.

The organization is responsible for a roughly $9.5 million, long-debated project that not only has removed the Graue Mill dam but also is restoring a 1.5-mile stretch of Salt Creek. Still to come are more studies and surveys of fish populations no longer hindered by the dam. And while those most familiar with the corridor are careful not to jump to conclusions, they say they’ve seen deer crossing the waterway, people fly fishing, kids skipping rocks and herons and egrets up and down the stream.

“The refrain that I constantly hear is that you can see the river coming back to life,” said Stephen McCracken, the workgroup’s director.

The dam debate

The dam was built in the 1930s by President Franklin D. Roosevelt’s Civilian Conservation Corps after the Forest Preserve District of DuPage County took over the property. As officials floated the idea of removing the dam, the three-story millhouse already was using an electric motor and did not rely on the water wheel for power. It was also lower than earlier dams that had powered the mill.

“They don’t perform a useful function anymore,” McCracken said. “The Graue Mill dam, of course, was actually a recreational dam, put in place to create an impoundment behind it for skating and such, which people really weren’t doing anymore. Plus the impoundment was filling with sediment.”

Still, the dam removal project was highly controversial. As a fixture on the landscape, the dam served as a backdrop for family and wedding photos. An online petition started by a former village president of Oak Brook to save the dam garnered more than 16,000 signatures.

But as scenic as it may have looked, the dam was hurting the waterway and the aquatic life that relies on it, experts said.

Monitoring of Salt Creek found very low dissolved oxygen levels immediately upstream of the dam. Sixteen native river fish species, including emerald shiner, johnny darter, northern pike and rock bass, were absent in areas upstream of the dam. The “impoundment” behind the dam spanned some 16 acres.

“You’re asking river ecology to try to live inside a lake environment, and that’s not what they’re evolved to do,” McCracken said.

“It was artificially wide for all those years, and people got used to that,” said Erik Neidy, the forest preserve district’s director of natural resources. “Now, it’s actually in its own natural course of where it should be.”

‘Much better habitat’

The corridor features a series of riffles — shallower, faster-moving sections — and more languid, deeper pools. Crews enhanced areas where there was a riffle or an elevation change but there wasn’t very much rock or cobble, said Neidy, who’s worked closely on the project.

“Those specific locations are where the water is oxygenated because it increases velocities. It creates much better habitat. Fish, mussels, macroinvertebrates love the cobble and love the rock,” Neidy said.

Caddisflies, for instance, take the small pebbles and create their “little cocoons” and live in those while they’re reproducing and feeding, he said.

For people navigating Salt Creek by canoe or kayak, the riffles — nine in total — offer a challenge course of sorts. You’ll find one example under the Fullersburg Woods flat bridge. Boulders are scattered across the creek.

“That then creates sound, the riffle action,” Neidy said on a recent morning as the creek gurgled in the background. “You can see that it’s stirring up the water, creating more oxygen.”

What’s ahead

Nearby resident Barb Collins can see Salt Creek from her property.

“People were saying the great blue heron and the white egret, they weren’t going to return because everything was changed. Well, they’re back,” Collins said. “We see owls, we see bald eagles, we see all kind of shorebirds here along the creek. So wildlife is back and enjoying it much more than they enjoyed it before as far as I’m concerned.”

As part of upland restoration work in Fullersburg Woods, invasive buckthorn and honeysuckle have been removed.

“We’ve had four nesting red-headed woodpeckers here this year, which we didn’t see in years past,” Neidy said.

The river restoration portion of the project — there’s still one pool left to construct — should wrap up by the end of September. Then comes the fall seeding.

“That will be all of our grasses, all of our flowers, all of this permanent seed that we want down,” Doohaluk said.

The project also calls for installing some 65,000 plugs. Crews will put in roughly 25,000 of those next spring. Experts next year will sample for fish and insects at the site.

“It feels good to get fish reintroduced to areas of the river where perhaps they haven’t been for 100 years,” McCracken said. “That does get you out of bed in the morning.”