The sprawling Napa Pipe complex may look old and ugly, but it's a developer's dream.

What other developable site in Napa encompasses 152 acres with full utilities, has visibility from two highways and panoramic views of the Napa River and the western hills? A railroad even runs through it.

If the era of steel manufacturing has ended, developers are unanimous that the Napa Pipe property is a potential showplace for the Napa of the 21st century.

Riverfront housing? A resort? A modern industrial park? The possibilities are limited only by the developer's imagination.

This is a "phenomenal site" for housing or a mix of residential and business park uses, said Glen Dowling, a broker with Cushman and Wakefield. "I think it will be gobbled up very quickly."

"It's an awesome property with huge potential," said Bret DeMartini, a commercial broker with Grubb and Ellis. This enormous, table-top flat site screams for redevelopment in creative ways that will suit Napa's growth needs, he said.

Until Oregon Steel Mills abruptly halted pipe production in July, this was "an out-of-sight, out-of-mind property," said Sheldon Davidow, former executive director of the Napa Valley Economic Development Corporation.

Now developers are circling. "I have at least one friend who has put a quiet offer on the table with the intent to develop it commercially," Davidow said.

Ray Adams, Oregon Steel's chief financial officer, confirmed a deluge of phone calls from developers sensing opportunity. The company is keeping all of its options open. For now, developers are told that the pipe plant is only "idle" and not for sale.

Asked when the property's fate will be known, Adams said, "It could be tomorrow. It could be six months from now. It could be a year from now."

Sensing that the days of heavy steel production are over, the city of Napa and Napa County have begun talking about the future of this strategically placed property. Officials say they do not want to harm the plant's chances of reopening, but they don't want to be caught flat-footed if Oregon Steel walks away.

The industrial site is of "strategic importance" to the city and county, said Howard Siegel, the county's community partnership manager.

Although Napa Pipe is in the county, it is surrounded on three sides by the city. The city's largest industrial park, Napa Valley Corporate Park on Highway 221, borders the mill on the east.

The property is too valuable for Oregon Steel to let it sit idle for long. Napa Pipe pays $432,000 in property tax, making it the county's 14th largest taxpayer. The property is assessed by the county at $41 million, with steel fabrication equipment representing more than half the value.

If pipe production does not resume, Oregon Steel can request a lower assessment, county Assessor John Tuteur said.

If redeveloped industrially, the 152 acres potentially could produce far more property tax for local government services. Dey Laboratories Inc., a pharmaceutical company located on a smaller adjacent site, pays $1.1 million in annual property tax on an assessment of $87 million.

Napa Pipe has produced sales tax windfalls for the county by occasionally landing major contracts within California. Twice within the past decade, the pipemaker paid $1 million or more in sales tax, said Pam Kindig, the county's tax collector.

The city and county agreed last week to include Napa Pipe in discussions of the future of industrial lands around the county airport and the 100-acre Syar rock operation on the east side of Highway 221, not far from Napa Pipe.

"The timing couldn't be better to look at redevelopment," said John McDowell, a county planner. The county has just embarked on a three-year process to update its general plan.

The current general plan shows Napa Pipe as industrial, reflecting its historic use, McDowell said. If the era of heavy industry is over, that designation needs rethinking, he said.

"It could be a marvelous environment for housing. It could be an extension of the industrial park," said Rich Bottarini, Napa's community development director.

"I think it's a great opportunity to plan something," said Napa City Manager Pat Thompson. Nothing significant is likely to happen for a decade, she predicted. By then, the city and county will need additional land for housing, she said.

The county will also have a future need for industrial land. South county has a limited supply of acreage to support job growth, said Charles Slutzkin, whose 300-acre industrial park, Napa Valley Gateway, has 100 acres remaining.

"Even at the glacial rate we're filling up, I assume in another six or seven years all of our land will be purchased," Slutzkin said.

Napa Valley Corporate Park, the adjacent 240-acre project started in the mid-1980s, is 70 percent spoken for, said Dowling. The Napa Pipe site is a rare opportunity for jobs and housing growth, he said.

The property has a rare commodity -- water access to San Francisco Bay -- but few industrial users would value this today, developers say. The site's rail link is a greater amenity.

Two negatives include the property's location in the Napa River flood plain and toxic contamination of the soil during earlier steel days. Oregon Steel has been implementing a toxics clean-up plan since 1990.

In theory, the Napa Pipe site could satisfy all competing interests, said Cassandra Walker, the city's economic development manager.

"I think it has some recreation potential. I think it has some housing potential. I think it has some corporate park expansion potential. It's big," she said.

If the property's future is to be different from its past, the city and the county need to agree on the new uses and who will control development, said Dan Schwarz, the Local Agency Formation Commission's executive officer.

Meanwhile, LAFCO will study whether Napa Pipe belongs in the city's sphere of influence, a precursor to annexation. The county has effective veto power on annexation, Schwarz said.

So do city voters who would have to approve expansion of the city's rural urban limit if annexation is proposed.

The ultimate veto, of course, lies 500 miles to the north. What will Oregon Steel want to do?