In a seemingly idyllic neighborhood of $300,000-plus homes, a serious and mysterious problem lies, literally, just below the surface.

Portions of 10-year-old streets are marked with roadblocks to keep school buses and garbage trucks from causing further damage. Worse, they could collapse into voids that have been found under streets, driveways and sidewalks throughout sections of the subdivision in LeClaire.

Some are large enough for a person to walk through.

“We bought our house new in 2002 and found sinkholes the first year,” said John Edwards, whose home at the corner of South 8th Street and Bridgeview Place appears to be at the epicenter of the subdivision’s erosion problems. “To us homeowners, this thing is cancer.”

Sidewalks and approaches, leading to large family homes with views of the Mississippi River, have sunk so far that some residents say their bumpers hit concrete when they try to pull into their driveways.

In the subdivision dubbed The Bluffs, a homeowner fell into a sinkhole up to her hip. About three years ago, a girl injured her ankle so badly falling into a sinkhole on her way home from the bus stop she required a cast and crutches for several weeks.

And, on Monday night, the LeClaire City Council is expected to vote on whether to add $120,000 to the $240,000 already being spent to mudjack portions of streets in the subdivision — just to fill as many underground voids as they can until spring.

Homeowner Kim Gasaway said the erosion under the streets creates such a hollow void, traffic sounds are amplified. She likens the vibrations her family feels from inside their home to being under an interstate overpass.

Gasaway’s advanced degree in environmental geology led her to a theory of what is causing all the problems.

“The land naturally had timber, lots of trees, and the substrate (conditions under the soil’s surface) is sandy and loosely packed,” she said. “With the clearing of the timber and removal of so much top soil, erosion control is diminished. Plus, they didn’t use any gravel under the roads when they built them. This leaves the substrate vulnerable to erosion.

“We should be calling this area The Caves at 8th and Bridgeview.”

No one knows for sure

City Engineer Brett Fetter, of East Moline-based McClure Engineering, also has a theory about the cause of the extensive, erosion-driven voids in The Bluffs.

When the roads for the subdivision were built, it is possible all was well, he said. It was not until home construction began that the “trickle” started. It began with further upset of the land, changing weather and the rain/mud runoff into the streets.

“It begins with a trickle, which becomes a stream and, ultimately, a river,” he said. “Until everything is well-healed, erosion continues.”

But homeowners argue the so-called trickle began with the clearing of the timber and farmland over a vulnerable substrate, which was made worse by road-building methods.

“Specifically, they didn’t use any gravel under the roads, which would have created a manageable path for the water,” homeowner John Edwards said.

As evidence of the problem, he shot home video during a summer rain. It shows water, bubbling out of the streets’ surface from the gaps between the concrete slabs. It also shows fast-moving paths of muddy water, about a foot wide, running down the curbs of South 8th Street.

Mayor Bob Scannell confirmed the roads were built without using gravel as an underground strainer for water.

“The first thing I did when I took office in 2008 was to change the city code to require gravel for new roads,” he said. “I also made (the code) more stringent to require 100 percent inspections. When it (The Bluffs) was built, they didn’t want an engineer there all the time, because it was too expensive.

“Something was done wrong, but I don’t know what it was. I don’t know if it was the city’s fault.”

The initial developer of The Bluffs, Walter Zimmerer, was not available to comment on his infrastructure methods. He also built about 100 homes in The Bluffs and others in Bettendorf before leaving Iowa.

On Nov. 20, the 70-year-old was sentenced to 30 days in jail and a year of home confinement after pleading guilty in federal court to nine counts of bank fraud in connection with construction loans he took from Quad-City banks in 2007 and 2008.

City councilwoman Terri Applegate said she thinks The Bluffs was headed for trouble from the start.

“We’re trying to deal with what’s left behind,” she said. “We are really, really working hard at getting some solution — if it’s there.”

The mayor harbors some skepticism, too.

“I’d say it’ll be $1 million or more to replace the streets ... if we can even solve it,” he said. “That’s the part that bothers me. I don’t know if we can fix it.”

What next?

The original engineering work for The Bluffs, which is in a residential tax-increment financing district, or TIF, also was done by Fetter’s firm, McClure Engineering.

He said he routinely assures city leaders there is no conflict of interest in his company doing both private and public engineering work for LeClaire.

He also has advised the city to wait out a solution for the subdivision’s erosion problems.

But Applegate insisted the city hire its own geotechnical expert after hearing a City Council presentation by Gasaway.

A curriculum specialist for the Davenport School District and a master educator for earth science, Gasaway pointed out what she saw as problems in the development that could be related to the natural condition of the ground under the streets.

Shortly after, Fetter also spoke to the council, saying Gasaway’s presentation was irrelevant.

On Oct. 15, Fetter wrote a letter to the mayor and council.

“… we stand by our recommendation that the City of LeClaire can learn from the experience and expense of Dubuque,” he wrote. “All of the technical data aside, the bottom line is that the City of Dubuque (along with many other Midwest communities) is experiencing extensive voids under the streets from highly erodable and collapsible soils and they are attempting a cost-effective solution to determine if it a feasible alternative. If the Dubuque project was not relevant, there would be no benefit to the City in waiting for the results.”

On Friday, officials in Dubuque said they do not know what problems McClure Engineering is referring to.

“It’s news to me,” Public Works Director Don Vogt said. “I’m not sure at all where they’re coming from on that. We haven’t even mudjacked in the city since the ’80s.”

Dubuque’s street and sewer maintenance supervisor, John Klostermann, had a similar response to questions about their “project” to address “extensive voids” as cited by Fetter.

“I’m not sure where they received their information,” he said. “You might want to check with Jon Dienst in our Engineering Department.

“While we have undermines that show up from time to time, they are mostly related to pipe failure or a mine shaft. In most cases, I would not consider them major and am not aware of any projects related to pavement voids or undermines.”

The city engineer also was confounded by McClure’s letter.

“I’m not aware of any issues with collapsible soils,” Dienst said. “We do occasionally have voids. I don’t know what they’re talking about.”

On Friday afternoon, Fetter said the co-worker who has been working with Dubuque’s consultant was not available.

Homeowners to blame?

When sidewalks and driveways first started to shift and sink in The Bluffs, city officials asked homeowners to take action.

“They told us to bury our gutters or move our gutters, so we did,” John Edwards said. “They said our gutters were pushing water down our driveways and sidewalks. When they found the giant holes under our sidewalks and the sinkholes started popping up, they said the water from our driveways was the problem.

“Doesn’t rain run off driveways and into the streets in every neighborhood?”

The mayor said he still thinks the location of gutters on many of the new homes contributed to the overall erosion problems. Although he said he “feels for” the homeowners, some of whom have replaced or mudjacked their driveways and sidewalks more than once, the remaining repairs “are the neighbors’ problem.”

One reason Scannell insists the residents must pay for repairs to their property is that the city already has its hands full. In fact, he said he is prepared for the news that entire streets in The Bluffs will have to be torn up and replaced.

“We don’t know what’s causing this. We really don’t,” he said. “I’m thinking the only way to fix it is to tear it up — from one end to the other. I’m astonished we ended up with something like this in a new subdivision.

“Once it started, it escalated bad.”

The city took what the mayor calls a “frugal” approach when the erosion problems first appeared in 2008. City officials took the advice of McClure.

“We tried these things that were like troughs, pushing the water to one side,” he said. “Obviously, that didn’t work. The engineers were kind of baffled.”

The city’s engineer said underground erosion voids are “a very common situation that we face in the Midwest.” He pointed out that many cities, including Davenport, account for mudjacking for public streets in their annual budgets.

Davenport Public Works Director Mike Clarke said older city streets are the ones to get the most attention.

“It dates back to construction practices many years ago,” he said. “Contractors, if we don’t catch them, they’ll just compact dirt and throw concrete on top of it. I’ve drawn a line in the sand. No contractor will ever be allowed to do that again in Davenport.”

In areas that were built before Clarke’s line in the sand, mudjacking is the only affordable solution, he said.

“The problem is, while it fills that void, the water still will go somewhere else,” he said.

As LeClaire waits, the tab for temporary mudjacking continues to rise, and residents worry their homes’ foundations will be the next victims.

Waiting for results

Edwards and his wife, Billie, are at their wits’ end.

Right behind them are their neighbors, including Annette Tephly; Mike Lacher; Jason Ciluffo and Michelle White; Rick and Debbie Kane; Don and Mary Wendel; and Kim Gasaway. Forty-two neighbors signed a petition in May, pleading with Scannell to include repairs to their sidewalks, approaches and driveways in the city’s budget for fighting the erosion.

“Homeowner investments in things, such as mudjacking, joint repair, concrete replacement, burying downspouts, backfilling sinkholes, etc., have proven futile,” Edwards told members of the City Council. “Conditions continue to worsen. This is not normal wear and tear.”

Amid all the complaints, growing problems, costly short-term repairs and no solid solutions, City Administrator Ed Choate said it is important to consider the big picture.

“This area we’re talking about is 1 percent or less of the total street network (of LeClaire), so let’s keep that in perspective,” he said. “The council’s made it a priority, as it should be. It’s going to be expensive. There’s no doubt about it.”

The mayor agreed.

“Right now, all we can do is make is as safe as we can,” he said. “I wish I could solve the problem for these people right now. I really feel for them.”

Meanwhile, Gasaway has considered more than one worst-case scenario for her family and her neighbors.

“I see two possibilities,” she said. “The city declares bankruptcy, because it is unable to absorb the liability, or the subdivision is condemned, and we all lose our houses.”