NOT IN MY back yard.

That sentiment is felt by some folks who live in the brick rowhouses across Haverford Avenue from Philadelphia's brand new, $110 million youth-detention center.

The city didn't fully consult with them before deciding to build in the Mill Creek community, some say, and now there is uncertainty over how property values, taxes and traffic will be impacted.

Some residents are working with the city to make the best of the situation.

City bigwigs cut the ribbon for the Philadelphia Juvenile Justice Services Center two weeks ago. The first teenage defendants are expected to move in from the old Youth Study Center in January. The sizing-up period in the working-class West Philadelphia community has long been under way.

"We went to meetings and they built it anyway," grumbled a woman who declined to give her name while unloading groceries from her car on Moss Street.

Mary Smith, 63, who lives several doors away and is one of 15 members of the detention center's community advisory board, was more optimistic about the community's newest neighbor.

"It's here, so now we have to work with them," said Smith, who is retired from the IRS and now a part-time school crossing guard.

"My thing is, who's over here? Our children. So, I'm about children," said Smith, who has lived in the Mill Creek community for more than 30 years.

"If these parents would control their kids, they would not end up there," added Smith, who home-schools grandson John, 17.

The new center replaces the Youth Study Center, which was housed for decades on Center City's Benjamin Franklin Parkway before being bumped in 2008 to an East Falls building to make way for the Barnes Foundation.

The new center, on five acres at 48th Street and Haverford Avenue, will house up to 150 young people between ages 13 and 20 who are waiting to be tried or transferred to longer-term facilities. The typical period of confinement will be from one to 12 days, officials said.

Joan Williams, the first vice president of the West Philadelphia Coalition of Neighborhoods and Businesses, said that although the city initially did a poor job informing the community about its "done-deal" plan to build the center, her group worked to get the word out and is now a partner to help things run smoothly.

Including a community room helped to soothe some who felt disrespected, Williams said, adding that the center will inspire her nonprofit organization and others to work harder to prevent juvenile crime so teens can avoid going there.

"That's what we've been trying to get people to see. There's some positive things that can come out of this now that it is here," Williams said. "People at this point seem to be willing to work with it until or unless something goes wrong or there's a problem."

But some are hanging onto the belief that the center is a conspiracy foisted on West Philadelphia by Big Brother.

Shawn Ford, 19, who lives on Mary Smith's block, sees a connection between the opening of the detention center and the school district's recent announcement that it plans to close 37 schools.

"Closing down schools is just going to help them use that," he said, pointing to the detention center.

"They knew what they were doing. If they close down schools, ain't nobody gonna want to go outside their school, so what they gonna do? They drop out. Bang, put them there," said Ford, who said he was on his way to Daniel Boone, one of the school district's disciplinary schools.