YBOR CITY — Construction work on a parcel of vacant land at 1309 Sixth Avenue has helped end one debate over the colorful history of Ybor City.

At the same time, though, it has touched off another.

An underground tunnel discovered on the property proved that similar shafts throughout the historic Latin District were built to serve as sewers for the city and not as smuggling routes for gangsters.

Still unknown is the location of Government Spring, one of downtown Tampa's first sources of fresh water. But people with an interest in the Sixth Avenue construction project think they have the answer, and it lies nearby. They just don't agree on where.

Daryl Shaw, who owns the property under development, says the historic spring is on the land next door at 1234 Fifth Ave — and the owner of that land, attorney Dale Swope, concurs.

But Gerry Curts, an Ybor City architect who sold Shaw the parcel a year ago, says it's on Shaw's land.

"It is on the land being developed," Curts said. "I saw it with my own eyes."

Actually, Curts saw equipment like a well with a bucket that might be attached to a spring but he didn't see water. Until the spring is uncovered, one expert says, the debate continues.

Curts has raised the question, he said, because he is concerned that the construction project underway on Sixth Avenue — a headquarters building for doormaker Masonite International — will permanently cover or even destroy the spring.

His fears were somewhat allayed when he saw architectural designs that feature an outdoor courtyard and a sidewalk on the southern portion of the Sixth Avenue parcel — the exact location, he believes, where the spring lies.

Still, Curts said, it's important to settle the debate because "Government Spring is one of the most significant historic sites in the Tampa Bay area. It is a cradle of our community."

It is where Native Americans drew their water 4,000 years ago, he said, and where troops camped during the Seminole Wars and the Civil War. As downtown Tampa and Ybor City rose from the ground, people here drank its water.

The exact coordinates of the spring are vague. Some newspaper archives over the past century place it adjacent to the old Ice Works building. Other articles say it was under the building.

According to an 1895 map, Ice Works first was located on the Sixth Avenue parcel, said Rodney Kite-Powell, curator of the Tampa Bay History Center. Kite-Powell is one who believes this parcel is the site of the spring. But an 1899 map, he said, shows the Ice Works moved to the adjacent property at 1234 Fifth Ave to become part of the Florida Brewing Co.

A well on the original Ice Works site was said to mark the spot of the spring. Next to the well was a pump house. The city of Tampa later erected a historic marker on the Sixth Avenue parcel.

In 1995, architect Curts bought the parcel. The marker had been stolen and, soon after his purchase, the decaying well and pump house were removed.

"A foot under the ground below the well was a concrete slab capping the well," Curts said.

But he never lifted that slab to search for the spring.

In 1999, attorney Swope bought the brewery and the Ice Works buildings at 1234 Fifth Ave for his law firm. While renovating Ice Works, crews discovered a 6-by-6-foot vault that housed a pipe and a pumping system.

What's more, Swope said, two years ago, water suddenly started flowing again from this pipe and pumping system and into his office.

"I am 100 percent confident the spring is on my property," Swope said.

But Bernie Greenberg, whose family once owned both the brewery building and the lot now being developed, is under the impression the spring is on the Sixth Avenue parcel. The Ice Works pump, he always believed, drew water in. Still, he admits his belief is fueled by memories of the historic marker more than anything else.

Brad Moore, superintendent of the Sixth Street property now under development, said no spring appeared during an infrared scan of the lot. Then again, Moore added, neither did the tunnel they discovered.

The only way to prove who is right may be to "go through the layers of earth at both sites," said Chris Anastasiou, head of the Springs Team with the Southwest Florida Water Management District.

Still, Anastasiou, said, it could turn out that the spring isn't beneath either parcel and both only drew from it.

The 1950 book A History of the City of Tampa and the Tampa Bay Region of Florida places the spring at 13th Street and Second Avenue, near Adamo Drive.

Spring mysteries abound, Anastasiou said.

What Tampa celebrates as Ulele Spring is a pool at the end of a pipe. The spring feeding it lies either under the road or a parking lot.

"We've never been able to find the exact location," he said.

Regardless of where Government Spring lies, Shaw would like to build a new well on his lot.

"It is part of the dialogue," said Shaw, who may also place a see-through courtyard floor over a portion of the tunnel on his lot. "We want to do everything we can do preserve history."

Contact Paul Guzzo at pguzzo@tampabay.com or follow @PGuzzoTimes.