BOSTON -- The city of Boston is drying up, literally. Much of the center of Boston was constructed on wet landfill, and as the water recedes, some building foundations are left on shaky ground.

NewsCenter 5's Pam Cross reported that receding water levels could create a multimillion-dollar repair job.

Across the city, 500 monitoring wells have been created to find out where the water is. The receding ground water has already affected a half dozen neighborhoods. "All of the Back Bay, South End, the Fenway, Chinatown, lower Roxbury -- it's a huge problem," said engineer James Lambrechts. Drusa Heidle loves her South End home, but recently contractors went under her foundation and found 13 inches of the wood pilings supporting the foundation exposed to air.

"The pilings are not in bad shape, but once the rot starts, it goes very quickly," said Heidle.

Fixing the problem can have high costs.

"Some people can afford to spend $250,000 to shore up a building and some can't. It has to be a citywide, state effort," said Heidle.

Experts blame Boston's building boom for the growing problem.

"Construction, deep pilings, high-rise buildings, subway tunnels, parking garages -- all the things that go down and may or may not cause leaks," said Susan Scott of the Groundwater Task Force.

"The woodpiles support cathedrals in Europe and they'll support these buildings for hundreds of years, as long as they're under water," said Lambrechts.

Fixing the damage will likely require federal assistance.

"The cost of underpinning one building (can be) $250,000 to $400,000. One street can multiply up into the millions," said Lambrechts.

It took decades for the problem to develop, and those with sinking foundations worry it may take even longer to fix.