Wet basement last year? Blame climate change

Drew Gardner lucked out when he joined the family concrete-and-waterproofing dynasty with a company of his own in 2013. One year later Minnesota had one of the wettest springs in state history, and his business could barely keep up with the phone calls.

Basement contractors were so deluged that they are still catching up today. "It was nuts — we couldn't put it in fast enough," Gardner said of a spring that saw 22 inches of rain from April to June.

Even though this spring has been unusually dry, climatologists say homeowners should get used to volatility — wild swings in weather will be more common as climate change begins working its effects on the atmosphere.

"The climate has been changing," said Peter Snyder, an associate professor of atmospheric science at the University of Minnesota. "It's pretty clear that we're seeing more extremes."

While last year's wet spring doesn't mean Minnesotans should expect flooded basements every year, Snyder said, his work indicates that intense weather events are becoming increasingly frequent in the Upper Midwest.

Last spring, Scott Wicklund and a crew of about 50 employees at Jesse Trebil Foundation Systems worked seven days a week to install interior drain systems. He said the company is still booked out until mid-May.

"Our revenues went up substantially — over $1 million more than what would be considered a normal year," said Wicklund, the company's general manager. "We almost couldn't react fast enough."

To install an interior drain, contractors create an indoor moat by building a trench along a basement's perimeter, laying down rock and pipe, and drilling holes into the foundation. Ultimately, the system channels water to a home's exterior.

Contractors say the installation, at an estimated average cost of $5,000, is one of few surefire ways to waterproof a home. It's also the first thing homeowners want once they've experienced flooding, as Wicklund saw last spring.

Rite-Way Waterproofing, which serves five states from its Lino Lakes headquarters, saw calls leap from a springtime average of 250 or 350 per week to 2,500 per week last spring, according to Jeremy Orton, general contractor manager.

Even though Rite-Way increased its workforce by about a third, Orton said, in June of last year the business was booked through October. By August they had appointments for interior drain installations into the new year. Now, he said, Rite-Way has mostly caught up, and has openings starting at the end of April.

The upcoming spring is expected to be dryer than last year's, when precipitation three to six times higher than normal fell onto soil already soggy from large amounts of melting snow, according to Craig Schmidt, service hydrologist for the metro area National Weather Service.

"There was really no more room in the ground to hold any moisture," he said. "So it was just running off."

Because climate change is a complicated and global phenomenon, Snyder said, it's not clear exactly how weather patterns will change — though he said a warmer atmosphere tends to contribute more moisture and precipitation.

Gardner is keeping his sights on this spring's rainfall and what it means for the cyclical business of waterproofing.

"When it rains, everyone wants it done yesterday,'' Gardner said. "But if it's a drought, like now, people think they're invincible.''

Marion Renault is a University of Minnesota student on assignment for the Star Tribune.