(CNN) -

The flood of unaccompanied children crossing illegally into Texas has prompted the federal government to action, after holding centers for them overflowed.

The General Services Administration plans to convert a warehouse in McAllen, Texas, into a processing center for the minors, according to a city building permit.

The U.S. Border Patrol will run the 55,702-square-foot building about 3 miles from the Mexican border that will temporarily hold up to 1,000 children.

It would seem like a drop in the bucket.

About 400 children cross into Texas per day, said Rep. Henry Cuellar. The Texas Democrat represents the district where most of them enter.

Many are seeking more opportunity or want to reunite with family. But violence in their home countries -- particularly Honduras, El Salvador and Guatemala -- is is helping create an acute tide of child migrants.

U.S. authorities estimate 60,000 to 80,000 children from Central America will arrive this year in the United States without a parent or guardian. Some of them are infants.

"This is a humanitarian crisis," said Cuellar. The government has no idea yet how it will feed, house and diaper the children.

Partisan fights

Political friction erupted over the inrush of unaccompanied minors after images appeared this spring showing some of them packed into detention centers in Arizona.

Republicans accused the Obama administration of not enforcing immigration laws.

Texas has been so overwhelmed that federal officials are transporting busloads of immigrants, including minors, to Arizona.

Arizona Gov. Jan Brewer slammed the move. "Not only does the federal government have no plan to stop this disgraceful policy, it also has no plan to deal with the endless waves of illegal aliens once they are released here," she said in a statement.

Pods, holding cells

A floor plan of the McAllen facility shows the building divided into four pods, with each pod containing five holding cells for 252 detainees.

Another floor plan shows a new chain-link fence around the property, temporary shower and laundry units, a play area, food service areas and an isolation area.

Each pod will contain an activity space with a raised agent observation station. The children will use portable toilets with hand-washing stations, and detainees will be separated by gender and further separated by age.

If it comes to fruition, the McAllen facility won't be the only one to house detained children. Naval Base Ventura County, which is outside Los Angeles, recently opened its doors to hundreds of children mainly from El Salvador, Guatemala and Honduras. Children also are being housed at Fort Sill, Oklahoma, and Lackland Air Force Base in San Antonio, Texas.

The General Services Administration has a 12-month lease. The building plans don't have a projected completion date.

Another new facility that will house 1,200 minors is in the works for Fort Sill. Oklahoma Gov. Mary Fallin has criticized the administration for over its decision to open it.