On the east bank of the Napa River, where vestiges of a 154-acre industrial pipe factory still stand, Napa Pipe developers are proposing a massive mixed-use development, the largest of its kind in Napa County history.

Napa Pipe would feature 2,580 small homes — reduced last year from 3,600 — a retirement center, hotel, restaurants, retail and office space and more. The project is headed to the Napa County Board of Supervisors for a vote next year, and if approved could be completed by 2022.

Since it was first proposed by Napa Redevelopment Partners three years ago, Napa Pipe has whipped up frenzied debate.

The fight has its roots in a landmark 1968 decision, when Napa County adopted the Agricultural Preserve and solidified one basic tenet: Agriculture is the best use of unincorporated county land.

Yet with pressure from the state to build affordable housing, it’s hotly disputed whether a large residential development at the industrial Napa Pipe site would threaten or further Napa County’s planning goals.

Proponents of the project say the industrial site is a perfect place to build homes without infringing on agricultural land.

Critics say the project is unnecessarily huge and lacks the necessary infrastructure.

“There are a number of really interesting planning questions at the point here,” Napa County Planning Director Hillary Gitelman said. “One is that the county is required, like all local agencies in California, to plan for and accommodate low-income housing. Being an unincorporated county that’s dedicated to preserving agriculture and open space and to directing urban growth into urbanized areas, the county has historically found it challenging, to say the least, to meet these state requirements.”

Napa Pipe opponents cite the long-standing local principle that cities are for housing and Napa County is for grapes.

“Napa County has, since the early 1970s, said that urban development belonged in the cities,” said Ginny Simms, a former Napa County supervisor and vocal critic of Napa Pipe. “Residential development is certainly one of those things that Napa County does not encourage in county areas. This development proposes to build a city about the size of St. Helena in an industrial area and, philosophically, that is not in keeping with our values.”

Eve Kahn, a local Realtor and like Simms a founding member of Get A Grip on Growth, acknowledged that Napa Pipe could very well provide much-needed affordable housing. “But to accomplish this, we need to throw out all the values that we created and that have made us the envy of counties and cities around the country and the world,” she said.

Others say Napa Pipe could be good for the Ag Preserve.

“In order to avoid sprawl into our ag and open space areas, we need to build up and not out,” said Napa County Supervisor Mark Luce. “This is one of the rare projects that in Napa can probably do that with minimum disruption.”

Under state law, supervisors have to plan for hundreds of affordable homes somewhere, Luce said. “If not this project, then where?”

“Napa County has a real conundrum with Napa Pipe,” Supervisor Bill Dodd said. “State housing policy requires the county to plan for housing. The county strives to protect agriculture, and not having a certified housing (plan) absolutely threatens the Ag Preserve.”

State law allows private citizens to sue if counties don’t comply with housing mandates, leaving open the prospect that counties lose control of land-use decisions. Said Dodd, “The result could very well be a judge overturning (Napa County’s growth restrictions) and setting some ag land as available for housing.”

Ultimately, Napa Pipe developer Keith Rogal said he believes the project could be “as important for protecting and preserving Napa as the Ag Preserve.”

“This is really the one big chance to do this,” Rogal said. “There isn’t another property that is urbanized, that has the physical resources to be developed in this way, in a way that can absorb our housing needs for the affordable housing requirements, which is both a moral and legal imperative.”

Said Rogal, “The property’s already paved. Something’s going to be on it. The people who are commuting here, they already are alive, and the jobs already are created. I think there’s a chance to be not just responsible but to do something exemplary.”