If Congress passes a law imposing strict penalties and fines for employers of illegal immigrants, the damage to Napa Valley’s $9 billion wine grape industry would be substantial, according to people in all levels of the industry.

Such a crackdown potentially could scatter much of the region’s labor pool. According to the U.S. Labor Department more than half of farmworkers nationwide are illegal, but farmworker advocates contend the overwhelming majority of California’s farmworkers are undocumented.

Like several fellow vineyard managers and others in the wine industry, Davie Piña, who owns and operates Piña Vineyard Management, said a sweep of illegal immigrants in Napa Valley would decimate the region’s agricultural sector.

“If they had a crackdown and found a whole bunch (of farmworkers) aren’t legal and we lost a whole bunch of people, the valley would be in a world of hurt,” Piña said.

Michael Wolf, who has run Michael Wolf Vineyard Services for 20 years, said people might initially panic if a labor shortage struck, but would inevitably adapt.

“In the short term it would be perhaps ‘Oh the sky is falling’ mentality,” Wolf said. “But then people would take deep a breath and say ‘OK, the sky didn’t fall on me,’ and they would gather up their resources and do something.”

Forced to scramble for labor and facing potential crop losses, the majority of Napa Valley’s growers would have no choice but to change the way they farm. Right now a majority of valley growers rely on a meticulous “one-human-to-one-vine” approach, widely believed to produce premium quality grapes and wines.

The romance and reputation of the Napa Valley is also perpetuated by this image of “guys out there hand-picking the grapes” said Steven Cuellar, a labor economist and professor at Sonoma State University.

More machines

If immigration shifts triggered a labor shortage, more growers would start turning to machines to harvest and prune, according to labor economists and people in the industry. Those who couldn’t do so because their vineyards are on terrain that is too rugged, too steep or otherwise unsuitable for mechanized harvesting would have to compete for the remaining workers.

Cuellar said if illegal immigrants were no longer available to work the fields, the shortened supply would push wages higher. But that doesn’t necessarily mean better jobs and a steady demand for labor in the long run, he said.

“If the shortage continues and (authorities) maintain efforts to reduce the number of illegal workers, generally wages for vineyard work need to rise to attract native workers. As those wages rise substantially, machine-picked might become more of an option for more growers.”

Napa County Agricultural Commissioner Dave Whitmer said several growers in the valley are already harvesting grapes mechanically, but they tend to be large-scale growers with valley floor vineyards more easily adapted to machines rumbling between the vines.

In other wine regions — Australia and Bordeaux, for example — mechanical harvesting is common, according to Jennifer Kopp, executive director of the Napa Valley Grape Growers.

“It’s a luxury for us to have the farm workforce that we have,” she said.

But many argue that the premium wine niche here wouldn’t exist without the relatively inexpensive, immigrant-dominated labor force.

“To try and mechanize everything would hurt the wine quality immensely,” Piña said. “Wines that go for $75 a bottle on up don’t machine-harvest, and you don’t machine-prune them.”

Hand-harvesting allows winemakers to drop individual grape clusters that are unripe or overripe, pick out leaves, shoots and dirt that might otherwise make it into the fermenter and lower the quality of the final product. With mechanical harvesting, those quality control practices would disappear.

Similarly, the work done in the months before harvest — thinning leaves to allow in the optimum amount of wind and sunlight, trimming the vines to encourage fruit production over vine vigor, and otherwise monitoring the crops — would diminish.

Michael Neal, co-owner of M&L Vineyard Management, pointed out that immigrants also make up the majority of the workforce in the winery cellars — the crushers, the forklift operators and the barrel washers.

“This commodity that we grow in Napa Valley needs a lot of hands. It’s a skilled labor force. It’s unlike any other region in California and its all winery-driven,” Neal said.

Paul Garvey of Garvey Brothers Vineyard Management in St. Helena said recruiting new vineyard labor in recent years has become more difficult.

“We’re sharing less workers and there’s more acreage being farmed,” Garvey said. He also said he believes the immigration debate this year is deterring many would-be immigrants from making an illegal border crossing.

According to Angel Calderon, who manages the River Ranch Farm Worker Housing Center, it’s a well-established belief among the farmworkers that crossing the U.S.-Mexico border today is riskier than ever.

Some seasonal workers who in the past would migrate to Mexico for the winter are staying put to avoid the frontier. Meanwhile, there’s talk of relatives in Mexico canceling plans to come north, Calderon said.

Fewer people

According to statistics from the Department of Homeland Security, the number of illegal immigrants caught crossing the U.S.-Mexico border in June and July dipped to the lowest summertime level since 2002. The number of Mexicans apprehended at the border this summer was 25 percent lower than the number captured last summer.

Garvey said he’s disillusioned with politicians who focus on tighter border patrols without addressing the fact agriculture depends on migrant labor from Mexico.

“It would be nice to have a program that makes it easier for workers to come and go. An employer could sign a document saying we need workers from this date to this date and people could come across the border safely. They’d know they have a job, and we’d know we have an employee,” Garvey said.

In theory, that already exists under a guest worker program run by the U.S. Department of Labor Employment and Training Administration. But the program is not as useful as employers would hope.

Kathy Mahoney, co-owner of Mahoney Vineyards, signed up for the program in June to recruit 10 guest workers by Sept. 1.

Today, harvest has arrived at Mahoney Vineyards, and the workers have not.

“I get so nervous I can’t sleep,” Mahoney said before harvest. “It’s frustrating because you’re dealing with agencies in Washington, D.C., California, Mexico and Chicago. That makes the program very clumsy because each agency has its’ own forms, fees, and time requirements.”

On Wednesday, Mahoney said she heard the workers she sought were getting a visa hearing in Monterrey, Mexico, today. They may get their visas by Friday, and be in Carneros before harvest is complete.

Meanwhile, local crews who have worked with Mahoney for years are going into overdrive to stay on top of things.

Mahoney says she would use the program, which she said balances the rights of native workers with the needs of employers, again. Said Mahoney, “It’s a program with a big heart ... and byzantine rules.”