The New Orleans field office of U.S. Immigration and Customs Enforcement is among a dozen nationwide where federal detention centers operate under contracts that guarantee jailers payment for a minimum number of inmates — a practice that critics say has sparked pressure from Washington to fill every bed — according to a new report by a national watchdog group.

The so-called “lockup quotas” don’t require all of the contracted beds, including 770 at a privately run detention center in Jena, to be filled. But the report, “Banking on Detention,” argues that the quotas, reinforced by some ardent members of Congress, encourage immigration officials to detain people regardless of whether they pose a risk to public safety.

ICE officials dispute the report’s contention that the bed minimums influence enforcement measures, describing the contracts as a mechanism to drive down taxpayer cost while ensuring the agency has enough beds to meet the congressional mandate.

The report, produced by Detention Watch Network along with the Center for Constitutional Rights, analyzed numerous contracts with public and private jailers obtained through federal Freedom of Information Act requests.

Congress mandates funding for 34,000 detention beds nationwide — a major chunk of the more than $2 billion budgeted annually for federal immigration detention operations.

The report found that more than 60 percent of those beds are run by private prison companies. Geo Group, one of the largest of the companies, operates the LaSalle Detention Facility in Jena under a federal contract that has grown to some $20 million annually since the 100-acre facility opened in 2007.

An official at the facility refused to say how many immigration detainees are housed there, referring all questions to the Geo Group website, which lists the capacity of LaSalle at 1,160 but doesn’t say how many detainees now reside there.

The report points to efforts by some members of Congress to change the language in the detention funding legislation to require not just that a minimum number of beds be maintained but that they be filled. The result, the report claims, is heavy pressure on ICE to do just that, particularly in facilities under “tiered” pricing contracts that cut the bed rate for detainees held above the minimum number.

Silky Shah, co-director of Detention Watch Network, said an “immigration dragnet” spurred a sharp rise in the number of people detained each year — from 384,000 in 2009 to 477,000 in 2012.

The contracts with private jailers also leave ICE officials “under pressure to move individuals to specific private facilities even if the individuals are from communities very far away,” said Ghita Schwarz, a senior staff attorney at the Center for Constitutional Rights. “This has a devastating human cost. It’s harder to hire an attorney, raise money for bond or otherwise fight your detention or deportation” at a great distance.

One Florida congressman said he plans this week to introduce legislation to bar ICE from signing contracts that contain provisions for a minimum number of detention beds at any specific facility.

Democratic Rep. Ted Deutch said the bed minimums contribute to a culture of detention, bypassing alternatives such as ankle monitors or intensive supervision, that ignores the fact some detainees “have passed credible fear interviews and should be eligible for asylum. They’re not a flight risk. They’re not a danger to our communities.”

ICE officials point to figures for 2014 that show more than half of immigration detainees were people previously convicted of crimes, including 85 percent of those removed from the interior of the U.S.

The New Orleans field office covers Louisiana, Mississippi, Alabama, Arkansas and Tennessee.

A local ICE spokesman said Louisiana is a “natural geographic hub” for detainees that ICE moves south for removal to Mexico or Central America.

The local cost per detainee runs about $40 per day, far lower than the national average of more than $100, according to the local field office.

Jennifer Elzea, a national ICE spokeswoman, said the bed minimums are a cost-effective way of ensuring that the congressional mandate of 34,000 daily detention beds is met.

“The availability of those beds in no way impacts ICE’s enforcement priorities or actions,” Elzea said in a statement. “ICE continues to make every effort while carrying out our mission to use efficiently the space for which we are expending resources.”

The report, which can be found at www.detentionwatch network.org, said half of the 24 ICE field offices nationwide have minimum bed contracts.

Along with New Orleans, they are Buffalo, New York; Denver; El Paso, Texas; Houston; Los Angeles; Miami; Newark, New Jersey; Phoenix; San Antonio; San Diego; and Seattle.

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