Milwaukee is sinking.
The walls and foundations of dozens of downtown buildings that stayed structurally afloat for more than 100 years on wooden pilings are deteriorating as once-sturdy Wisconsin pines, oaks and cedars rot. The culprit is declining groundwater that preserved the supports.
From Boston to the seaside town of Coos Bay, Oregon, pilings are rotting, undermining homes and neighborhoods. Drought, over-use of water and crumbling subterranean drains that channel away moisture are to blame in Milwaukee, hydrologists say. While Wisconsin courts hear a fight over who should pay, there’s a growing realization that water scarcity is no longer the singular worry of dry and newly built regions.
“We’ve left the century of oil and now we’re in the century of water,” said Peter Annin, author of “The Great Lakes Water Wars,” a 2006 history. “Water tensions are the new normal, no matter where you live, and this is just the latest example of that.”
The tale of wood and water is told in inches -- as in how much buildings have slipped. Milwaukee’s consciousness was aroused in 2000 by a newspaper report that said sewerage commissioners were meeting behind closed doors to consider a $500,000 claim from the owners of Milwaukee Auditorium, who said the structure had sunk as much as 3 inches.
They blamed cracks in a deep tunnel built at a court’s order to reduce raw sewage dumped into neighboring Lake Michigan. The commissioners approved a $200,000 payment. In ensuing years, claims mounted as other foundations sagged.
Owners have gone to great lengths to protect their property, some of it historic.
Two structures on the Northwestern Mutual Life Insurance Co. campus were built on 7,000 wood pilings and engineers measure groundwater by peeping through several four-inch holes in the basement of the 102-year-old main building, which resembles a Greek temple.
They drain water from the roof to douse the timbers and recycle 5,000 gallons used monthly to test the sprinkler system. The company is now installing an alarm that signals when water is too low.
“Expensive is a relative term,” said Scott Wollenzien, facility operations consultant for Northwestern Mutual, the No. 2 seller of life insurance in the U.S. last year. “We built this building to last a hundred years. We expect it to last at least another hundred.”
The wood that supports scores of cities is deteriorating as groundwater falls and it’s exposed to the effects of oxygen. The pilings were driven in a common 19th century construction technique to compensate for spongy or marsh-like ground. It predated steel and concrete and, as long as water stayed above the timbers, it worked.
“This is a warning to others,” said James Lambrechts, an associate professor of civil engineering at Wentworth Institute of Technology in Boston. “In Milwaukee and here, people didn’t realize they had a groundwater issue until the pilings started to rot.”
Lambrechts wrote a 2008 study charting Boston’s challenge of protecting row houses and other structures of the Back Bay, South End and Fenway neighborhoods, dating to the 1800s.
The old German town of Milwaukee developed from marshland, starting in 1846 and, with breweries such as Pabst, Schlitz, Blatz and Miller, slaked the nation’s thirst.
The cause of the sinking of the city of 600,000 on Lake Michigan’s southwest shore is the basis of a 12-year court battle. The owner of a damaged downtown department store building sued the Milwaukee Metropolitan Sewerage District in 2002, claiming a 28-mile (45 kilometer) tunnel stormwater system that opened in 1993 has been draining groundwater from above and undermining the foundation. Bostco LLC sought $11 million to repair the pilings.
The district blamed the declining level of Lake Michigan, which is affected by rain and snowfall. Lining the tunnel with concrete to seal cracks would cost taxpayers tens of millions of dollars and shut the system for a year, a spokesman said.
In July, the Wisconsin Supreme Court ruled the district would have to fix the leaks. However, the justices returned the case to a circuit court to determine how repairs should be made and reduced the district’s liability to $100,000 because of a state law capping awards from government agencies.
Dozens of other buildings are affected. Milwaukee’s City Hall, an 1895 structure listed on the National Register of Historic Places, is working to save its foundation of oak and pine. The Milwaukee Repertory Theater recently estimated it will cost $1.75 million to fix its foundation.
By the time the Bostco lawsuit was filed in 2003, the district had paid more than $7 million to fix foundations of 17 downtown buildings, according to the owners and court records. They included the Marcus Center for the Performing Arts parking structure; the Bradley Center, where the Bucks of the National Basketball Association play; the Milwaukee Theatre; the Shops at Grand Avenue; the Hyatt Regency hotel; and Usinger’s Weiner Works.
Bill Graffin, a spokesman for the district, didn’t respond to a request for information on payouts since then.
Groundwater across the nation is stressed, according to a report from the U.S. Geological Survey. While climate change, drought and faulty infrastructure all can contribute, there is no refuting falling water levels.
Sinking land is also occurring out west, where farmers have been over-pumping groundwater in California’s San Joaquin Valley to feed crops, inadvertently draining the aquifer in the U.S.’s most productive farming area. Parts of the Central Valley are subsiding as much as a foot a year, damaging bridges and canals, according to the San Jose Mercury News.
In Milwaukee, the deep tunnel has fissures through which 2.8 million gallons leak in every day, court records show.
“It’s a big deal in some places,” said Devin Galloway, a hydrogeologist for the U.S. Geological Survey. “The dry rot process doesn’t take that long once the material dries out.”
Galloway has studied foundation depletion in the Netherlands, where declining water levels have left structures built in the 16th and 17th centuries “visibly leaning and deformed.”
The sinking of Milwaukee doesn’t afford easy solutions. A century-old, three-story building was demolished last month because the structure was beyond repair. Others have been saved -- at a cost.
Franklyn Gimbel, a lawyer who is chairman of the board of the Wisconsin Center convention hall, said the sewerage district paid more than $200,000 to shore up Milwaukee’s old auditorium. It wasn’t enough. The board later learned that the ground wouldn’t support an expansion, and modifications added $10 million to the project.