The controversial Napa Pipe development proposed for south Napa County would create thousands of jobs and pour billions of dollars into the local economy, according to a report commissioned by Napa Pipe developers.

A fiscal impact report prepared by Economics Research Associates projects that the Napa Pipe project would bring $2.1 billion to Napa County and create 1,300 permanent jobs.

Between 2010 and 2020, Napa Pipe developers would spend approximately $1 billion on construction, according to the report, resulting in a $1.6 billion boost to Napa County’s economy in direct and indirect impacts. During the same time period, new residents and employees at Napa Pipe would generate a reported $440 million, bringing the total benefit to Napa County to $2.12 billion, according to the report.

During the 11-year anticipated build-out period, Napa Pipe would create 1,200 jobs annually, the report states.

When the project is completed in 2020, the report states, ongoing expenditures from new employees and new residents at Napa Pipe would add $92 million annually to the Napa County economy and result in 1,300 permanent jobs.

The report assumes that the Napa Pipe development would include industries that would both bring in new money from outside of Napa County and encourage the circulation of existing money in the county. For example, the report points out, the proposed condominium hotel would attract visitors who may not otherwise have chosen to stay in Napa County. The report estimates that Napa Pipe would bring in about 53,000 tourists a year once the hotel is built in 2013.

The report does not address whether or not the Napa Pipe hotel would siphon away money from the other hotels proposed for Napa County, a concern that some critics of the project have expressed.

The majority of the jobs immediately created by the Napa Pipe project would be in construction, according to the report. During the final year of the pre-construction period, it is expected that Napa Pipe would create 180 jobs a year.

In 2014 — at the end of the first of three proposed construction phases — the report projects Napa Pipe would create 1,350 new jobs, mostly in construction. The number of new jobs would jump to nearly 2,200 by the end of the third phase in 2020, according to the report, with far more jobs coming from the commercial development of the property.

Eve Kahn, chairwoman of the group Get A Grip On Growth, which opposes the Napa Pipe project, is skeptical of the report’s results, though she acknowledges she has not reviewed the report itself.

“In general,” Kahn said, “homes do not cover the cost. If you build housing, it almost never covers the cost of services” provided by government agencies, such as police, fire and schools.

However, a previous report from 2008 maintained that the Napa Pipe project would have no negative impact on the local governments responsible for providing services to its residents.

The new study is one of several as the environmental impact report is prepared for the controversial project, the largest of its kind in the history of the county. If approved, the mixed-use development on the site of the former Napa Pipe and Kaiser Steel operations would feature 2,580 townhomes, a hotel, restaurants, office space and light industrial use.

The environmental study is expected to go before the Napa County Board of Supervisors later this year. County officials have been interested in the project because it would help the county reach affordable housing goals for years to come. Officials from the city of Napa oppose the project, which is just outside city limits.