A south-metro church is preparing to make its mark on Shakopee with a sprawling megachurch.

River Valley Church is completing plans to build a 30,000-square-foot, $4 million campus in the city's Southbridge neighborhood, according to church and city officials. The development is meant to replace the church's home in Savage and accommodate its rapidly growing membership.

River Valley, an Assemblies of God congregation, is one of the fastest-growing churches in the country. According to church records, attendance has more than doubled in the past four years, swelling to nearly 5,000 this month. Lead pastor the Rev. Rob Ketterling said that during the holidays, River Valley attracts up to 8,000 worshipers.

Three of the church's seven locations -- including a site in Valencia, Spain -- opened in 2012. Growth has slowed slightly in the past year, Ketterling said, but only because River Valley is straining its available space. The flagship church in Apple Valley seats 1,000 and holds four services weekly to accommodate its growing congregation.

"Some of our facilities have hit the max," Ketterling said. "There are a few of our campuses that have hit ceilings, and we're trying to figure out how to make more room for growth."

The Shakopee location will initially have room for 800 worshipers. Eventually, the church plans to relocate its headquarters there. That project will add a new 2,000-seat auditorium, Ketterling said.

River Valley's worship spaces eschew traditional vaulted ceilings and stained-glass windows in favor of state-of-the-art audiovisual equipment. Each church has its own pastor who leads services, and Ketterling's sermon is broadcast to each congregation over giant screens in the auditoriums.

This embrace of technology reflects River Valley's nontraditional worship style. Services are lively, often featuring a strong video element and rollicking performances by a worship band. Ketterling said it's not unusual to see congregants using smartphones and tablets during services to look up Bible verses, take notes and tweet.

"We'll even encourage people," he said. "I think in this day and age, with social media, a tweet is like an 'amen!'"

River Valley has not filed any use permit applications or other paperwork with the city, according to Community Development Director Michael Leek, but selection of the Southbridge site comes after about six months of discussion between the church, city planning staff and Shakopee Mayor Brad Tabke.

The church originally applied to build on a vacant 20-acre parcel along Hwy. 169 near Dean Lakes, Leek said. That site had all of the elements Ketterling said he looks for in a new campus: It was easily accessible and visible from the highway, with plenty of room for expansion.

However, the city attempted to guide development away from the site, which is a planned business park, a zoning designation that does not typically allow churches, Leek said. The city showed River Valley a few potential sites before the church settled on the parcel in Southbridge.

The city would have lost at least $219,000 in property taxes if River Valley had bought the parcel near Dean Lakes, according to county records.

Tabke said the city steered the project away from Dean Lakes because of the potential for job creation in the burgeoning commercial district.

"We have very high and significant job-growth plans for the city, and especially for that particular area," Tabke said. "They were going to take a large part [of the business park] where the city had invested a significant amount in infrastructure and planning to have jobs there."

River Valley is still assessing how much of the new 60-acre Southbridge parcel it will purchase, Ketterling said.

Leek said River Valley is the largest church he has worked with in his time with Shakopee. He said the church's use application will likely require a traffic study to assess the potential for congestion around the development.

Though nothing concrete has been planned, Ketterling and Tabke both expressed interest in holding community meetings and events at the facility, something Ketterling said happens frequently in Apple Valley and at other campuses.

"A church like ours also can bring state-of-the-art facilities and sometimes the largest meeting space in the entire city," Ketterling said.

Many Shakopee residents already attend River Valley, Tabke said, because the church had previously absorbed a small congregation that had been meeting at Red Oak Elementary School. Tabke said he is excited for River Valley to bring that now much-larger congregation back to Shakopee.

"They do such amazing work," he said. "It will be a great addition to Shakopee if everything can get done well."

Tony Wagner is a University of Minnesota student on assignment for the Star Tribune.