In 2006, ground was broken for Rego Park Center, a seven-acre, $550 million mixed-use development. Developer Vornado Realty Trust plans to include a Home Depot, a Kohl's and a Century 21, plus a 1,400-space parking garage and two residential towers. The project has the blessings of the mayor, councilwoman Helen Sears and Queens Community Board 6 district manager Frank Gulluscio. The residents of the nearby co-ops thought it would be good for the neighborhood.

Trouble began when construction crews began to dig a 25-foot-deep hole in the ground. "When they started work there was a lot of shaking," says Diane Barton (below) of Metro Management Development, resident manager of the twin high-rise Park Plaza co-op across the street. "Things were falling off walls."

That was just the start. Once the excavation reached an aquifer 10 feet below ground, the builder, Bovis Lend Lease, had to divert the ground water into the city's sewer system before digging could resume. In engineering circles, this around-the-clock pumping is known as "dewatering." By the end of May, "Our garage floor started doing strange things — buckling, cracking," says Barton "We noticed especially that the floor areas around the support pillars were sinking. Now it looks like we have speed bumps all over our garage."

Barton notified the co-op's architect, Howard Zimmerman, and the city's Department of Buildings (DOB). "Residents were fearful," she says. "We had to assure them that the building was not going to collapse."

A preliminary investigation indicated no danger of that, but Zimmerman recommended that the co-op get a more detailed opinion. So the board hired Mueser Rutledge Consulting Engineers to take soil samples and measure ground water, in an effort to document that the dewatering at the construction site had caused the garage floor to buckle and sink.

Then, on June 14, an elderly resident of the co-op tripped and fell on the uneven garage floor. Only then did the developer and builder send representatives to examine the garage, according to Barton. They told her that the irregular pavement was the result of "normal settling" — in buildings that had stood almost 50 years without any settling, normal or otherwise. "They wouldn't even acknowledge that they were causing the problem," says Barton.

In December 2007, the problem spread two blocks east to Park City Estates, a co-op with five 17-story buildings and more than 1,000 apartments. One day, "as I was coming from the garage into the building," recalls General Manager Charles Zsebedics (pronounced Ze-BED-ix) of Century Management Services, "I noticed the floor of the garage was sinking," says Zsebedics (below). "I thought, ‘That's a problem.' "

Theorizing that underground water pipes must have burst, the co-op's staff dug up the asphalt around the spot where the garage floor had sunk. There were no burst pipes. "I immediately put two and two together," Zsebedics says, "and thought this has to be caused by the dewatering" at the construction site.

The problem turns out not to be confined to the two co-ops' garages. A walk through the neighborhood reveals that streets have sunk, many sidewalks are sunken and/or cracked and several buildings have separated from their surrounding sidewalks.

But as the two co-ops were about to learn, making a reasonable deduction based on plainly visible empirical evidence is not enough when it comes to fighting a big developer, its insurance company and a high-profile project with the hearty blessings of the powers that be.

Fighting City Hall

The co-ops banded together. Mueser Rutledge, Park Plaza's engineering firm, drilled four wells in the Park City Estates garage to gather additional soil and groundwater evidence and monitor changes in the water level. The growing body of data began to look promising.

"From publicly available information, we estimated that the water level was originally about 10 feet below the ground surface," says Jong Choi, a geotechnical engineer with Mueser Rutledge. "Based on our research, we found that the groundwater level was substantially depressed by their pumping activities — to about 35 feet [below ground level] under Park Plaza and about 29 feet under Park City Estates. We believe the water level was brought down by dewatering."

Such changes have predictable consequences. "When groundwater level drops, soil loses its buoyancy," Choi continues, "We call that 'consolidation.' That's what's causing the garage floors and sidewalks and streets to crack and settle."

Choi estimates it could be weeks or several months before the water table stabilizes. Only then will he be able to produce a final report for his clients. Zsebedics and Barton, meanwhile, were bringing the problem to the attention of politicians and city agencies. Zsebedics also sought a stop-work order from the DOB — an effort that proved fruitless.