It was more than just a potential blow to Rochester’s self-image when federal authorities warned of action that would have turned the Rochester International Airport into the Rochester Municipal Airport.

Millions of dollars were possibly at stake after the airport’s 450-square-foot customs facility, operating in another part of the airport since 1995, had been found to be inadequate by U.S. Customs and Border Protection, threatening the future of international arrivals to the Mayo Clinic and southeast Minnesota area businesses.

Members of Minnesota’s congressional delegation recently announced a $7.3 million U.S. Department of Transportation grant that will go toward improving the customs facility. The new 20,000-square-foot project in the main terminal will provide for a passenger boarding bridge, a concourse holding room, a baggage claim, improvements to security screening and a better operation to process business and VIP flights.

The Department of Homeland Security had issued an unfunded mandate to replace the existing facility at an anticipated cost of $12 million. Without the improvements, customs would have moved from the airport and its “international” designation would have been pulled.

“Rochester is a destination city for people all over the world, including those traveling to and from our world-class Mayo Clinic,” U.S. Sen. Amy Klobuchar, D-Minn., said in a statement announcing the grants. “Today’s investment will help make for a smoother, safer trip through the Rochester airport for international travelers.”

U.S. Sen. Al Franken, D-Minn., and U.S. Rep. Tim Walz, D-Minn., who represents the area, joined Klobuchar in the announcement.

“Rochester International Airport is critical to the economic vitality of southeast Minnesota,” Walz said in a statement. “These resources will help modernize the facility, improving the experience for passengers traveling to and from Rochester.”

No regular international flights are scheduled to Rochester, but more than 200 private flights deliver a total of 1,300 passengers to the city every year.

Rochester officials estimate the flights have a $3 million to $3.5 million economic impact on the region. International visitors stay for an average four days and spend $625 a day.

“It’s huge access to southeast Minnesota and the employers who are based here,” said John Reed, the airport’s executive director. “I’d hate to think what we would be in the region if we did not have that ability.”

The $7.3 million federal grant completes funding for the project, even as hoped-for $5 million bonding capital from the state stalled. The Rochester City Council has increased its contribution to $3.8 million and the Minnesota Department of Transportation is kicking in $790,000. Reed said officials continue to hope for state bonding aid, which could allow the city to divert some of its contribution to other projects.

After the final design is complete, the project could be finished within 12 months, Reed said.

Maintaining the airport’s international status will be a critical element in Rochester’s efforts to remake itself under the Destination Medical Center plan, a Mayo Clinic-driven effort to maintain the city’s prominence in health care, medicine and research.

The 20-year project blends billions in private investment with $585 million in public dollars while remaking the city into a destination in its own right.