HOUSTON/SAN FRANCISCO (Reuters) - In the coming weeks, as Houston turns its attention to rebuilding areas devastated by Tropical Storm Harvey, people like Jay De Leon are likely to play an outsized role – if they stay around.

REFILE -- CLARIFYING LOCATION Jay De Leon, of Houston, Texas adjusts his chain saw as he works in his neighbor's backyard in Houston, Texas, U.S., August 30, 2017. REUTERS/Mica Rosenberg

De Leon, 47, owns a small construction business in Houston, and he and his 10 employees do exactly the kind of demolition and refurbishing the city will need. But like a large number of construction workers in Texas, De Leon and most of his workers live in the United States illegally, and that could make things complicated.

The Pew Research Center estimated last year that 28 percent of Texas’s construction workforce is undocumented, while other studies have put the number as high as 50 percent. Construction employed 23 percent of working undocumented adults in Texas at the end of 2014, higher than any other sector, according to the Migration Policy Institute.

However, undocumented immigrants are growing increasingly nervous in Texas because of an immigration crackdown by the Trump administration that has cast a wide net.

In addition, undocumented immigrants were worried about a new Texas law that had been scheduled to take effect on Friday, which would have barred cities in the state from embracing so-called sanctuary policies that offer safe harbor to illegal immigrants, and would have allowed local police to inquire about a person’s immigration status.

That law was temporarily enjoined by a federal judge late Wednesday, but the state’s governor has vowed to appeal.

De Leon, who has lived in the country for 20 years and has two citizen children, says the changes have spooked the city’s migrant workforce. In recent weeks, he said, one of his employees left the state and another returned to Mexico. Both feared that if they stayed they risked arrest.

Departing workers, he says, pose a problem for Houston in the wake of Harvey, which has killed at least 17 people and caused flood damage to commercial buildings, houses, roads and bridges expected to run into tens of billions of dollars.

“The situation that Houston is going through now with the hurricane is going to be the trial by fire for the Republicans and the governor that approved these radical laws,” De Leon said. “They will need our migrant labor to rebuild the city. I believe that without us it will be impossible.”

Undocumented workers perform a wide range of construction jobs, from framing and dry-walling to plumbing and wiring.

Stan Marek, chief executive of Marek Construction in Texas, said his company doesn’t hire undocumented immigrants and has long had difficulty finding enough trained U.S. workers.

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“It’s a crisis,” Marek said. “We are looking at several thousand homes that have flood damage. There is no way the existing (legal) workforce can make a dent in it.”

Marek would like to see the federal government grant emergency work authorization for undocumented workers in the rebuilding effort, he said. Otherwise, those immigrants are likely to be hired by firms that do not pay payroll taxes or provide benefits like workers’ compensation and legally mandated overtime.

It isn’t yet possible to estimate how many construction jobs will be added in Texas as it rebuilds, but in the 12 months after Hurricane Katrina hit in 2005, Louisiana added 14,800 jobs in the sector, U.S. government data shows.

About 25 percent of the construction workers involved in the cleanup of New Orleans were undocumented, according to a study by researchers at Tulane and UC Berkeley universities. Those without papers were “especially at risk of exploitation,” the study found.

WORKER EXODUS

The labor shortages are likely to grow worse, many builders warn. Earlier this year, a group of Hispanic contractors sent a letter to Texas Governor Greg Abbott warning that the pending ban on sanctuary city policies would make it “difficult to find and retain experienced workers.”

Javier Arrias, chairman of the Hispanic Contractors Association de Tejas and one of the letter’s signers, told Reuters that “many construction workers are already moving to other states.”

Abbott’s office did not respond to a request for comment about the role undocumented workers might play in the recovery.

Elizabeth Theiss, president of Houston-based anti-immigration group Stop the Magnet, sees another option besides looking to workers in the country illegally. She says the rebuilding effort should be used to help train U.S. veterans and other citizens who need jobs.

Theiss acknowledged that reconstruction might proceed more slowly, at least initially, if immigrants without work documents are not part of the effort, but she noted that rebuilding would be slow under any scenario.

PERSONAL HARDSHIPS

Whatever role undocumented people play in rebuilding Houston, they could face hardships rebuilding their own lives.

While the Federal Emergency Management Agency provides emergency food, water and medicine to anyone, regardless of immigration status, cash assistance and other longer term aid is only available to citizens and immigrants in households where at least one family member has legal status.

Immigrant advocates are launching private fundraising drives to help fill the void.

“It is deeply tragic and un-American that so many of those working men and women who will be rebuilding Houston and the rest of the state will be doing so while facing tragedy in their own lives,” said Jose Garza, executive director of the Workers Defense Project.

De Leon said his family was lucky and did not suffer flood damage. He is now busy rounding up supplies for immigrant families stuck at shelters who are afraid to seek out more help from authorities.

In the end, he says, President Donald Trump has to know “it’s going to be impossible to rebuild Houston without the labor force of immigrants. It is illogical - what he says with his words and what really has to happen.”