Washington (CNN) As a potentially catastrophic hurricane bears down on the East Coast of the US, the shifting of $10 million from FEMA's operating budget to fund immigration detention and deportations is drawing condemnation from Democrats.

But that's a drop in the bucket.

The Trump administration this summer quietly redirected $200 million from all over the Department of Homeland Security to Immigrations and Customs Enforcement, despite repeated congressional warnings of ICE's "lack of fiscal discipline" and "unsustainable" spending.

The Department of Homeland Security asked for the money, according to a document made public this week by Oregon Sen. Jeff Merkley. Of the $200 million, the document says $93 million will go to immigrant detention, a 3% budget increase that will fund capacity for an additional 2,300 detainees; and $107 million for "transportation and removal," or deportations, a 29% budget increase.

The move comes as the Trump administration has pursued an aggressive immigration agenda, ramping up arrests of undocumented immigrants and deportations.

In addition to this summer's widely condemned move to separate families at the border, the administration has drawn criticism for arresting a far greater rate of noncriminal undocumented immigrants and seeking to detain them much longer. On Tuesday, the administration announced it would tripling the size of an emergency temporary tent facility to house more immigrant children.

The additional $200 million would put ICE's budget for detention and transportation at more than $3.6 billion.

The money came from different parts of DHS, including FEMA, the Countering Weapons of Mass Destruction Office, Federal Law Enforcement Training Centers, Coast Guard, Transportation Security Administration, cybersecurity office and Customs and Border Protection.

DHS and ICE did not immediately respond to a request for comment about the overruns.

The $10 million from FEMA did not come from the agency's disaster relief budget, the agencies noted. "DHS/FEMA stand fiscally and operationally ready to support current and future response and recovery needs," said FEMA spokesman Tyler Q. Houlton.

DHS made the request to move the money around to congressional appropriators, who approved the plan, this summer, according to Detention Watch Network Policy Director Mary Small, whose group obtained the document and provided it to Merkley.

Congress sets funding levels for all parts of government through the appropriations process, but funding reprogramming requests like this one are authorized under the law for relatively small amounts of money within agencies.

The department then must notify the chairs of the relevant congressional appropriations subcommittees, who must approve. Since Republicans are in the majority for both the House and Senate, those lawmakers lead the committees. Both signed off on this reallocation, Republican and Democratic aides told CNN.

Small said the request was part of a broader problem, and accused ICE of "robbing" money for themselves to expand their deportation and detention capabilities even beyond what Congress intends.

Congress has long restricted how much money goes to ICE as a way of forcing it to prioritize its immigration enforcement efforts. ICE only has roughly 40,000 spots in detention, meaning it cannot possibly detain every undocumented immigrant in the US. Keeping its funds at a certain level allows Congress to control just how much enforcement can be done.

But ICE has overrun that amount and requested more money regularly.

Congressional records indicate that ICE reprogrammed $83 million combined in fiscal years 2014 and 2015, and another $127 million in fiscal year 2016. Those requests are not generally not made public.

"(It's) this pattern of misbehavior by ICE where they overspend the amount they have been given by Congress, specifically for immigration detention, and then they make it up by basically robbing other accounts in DHS," Small said.

Lawmakers unhappy with ICE spending

The Republican-led Congress has previously reprimanded ICE for its spending habits.

The House's 2017 explanatory statement for homeland security funding for that fiscal year, as preserved in the Congressional Record , called "financial management weaknesses" a continued "particular problem" with ICE's Enforcement and Removal Operations.

"The lack of fiscal discipline and cavalier management of funding for detention operations, evidenced by inaccurate budget formulation and uneven execution, seems to be the result of a perception that ERO is funded by an indefinite appropriation," the statement said.

Similar language is popping up in this year's appropriations bills.

"ICE continues to spend at an unsustainable rate," the Senate Appropriations Committee report accompanying its proposal for Homeland Security next fiscal year says. "In light of the Committee's persistent and growing concerns about ICE's lack of fiscal discipline, whether real or manufactured, and its inability to manage detention resources within the appropriations made by law without the threat of anti-deficiency, the Committee strongly discourages transfer or reprogramming requests to cover ICE's excesses."

Small says that her group is "on the Hill screaming about this" to encourage Congress to break the pattern.

"These are real shenanigans that need to be reined in, not just from a good governance standpoint but also from the standpoint that these are other accounts that need the money," Small said.