At the submarine base in Groton this week, 750 civilian employees are receiving furlough notices that they’ll be off one day without pay each week for 11 weeks starting July 8, through the end of the federal fiscal year.

The furloughs are forced by sequestration, the mandatory, across-the-board spending cutbacks in federal spending. Capt. Marc W. Denno, commanding officer of the base until the end of this week, said safety and essential services would not be affected — but morale is a different story.

The base has about 1,300 civilian employees, Denno said in a written statement, and the 750 targeted for furloughs work in a wide variety of areas.

“Certainly the loss of work-hours from these dedicated and integral members of the team will impact base efficiency and support effectiveness,” Denno said in the release. In addition to sparing safety and security, he added, “Family Services such as Child Development Centers will not be affected.”

The furlough is believed to be the largest to his Connecticut since the White House and Congress had a budget meltdown at the end of 2012 that led to the mandatory cuts. The sub base furlough — which amounts to the equivalent of about 35 jobs in total number of hours — is larger than the cuts that would have led to the closing of six airport control towers; those closures were averted.

The base “has taken great effort to try to limit the visible impacts that patrons of facilities, or tenant customers of base services, may see,” Denno said.

Some services have already been curtailed, including hours of the base gym, pool and library, and the commissary might close an additional day, Denno said.

“Of course, all of this impacts morale and productivity, and keeping Navy Team New London focused and moving forward is going to be my challenge through the end of this month and Capt. Carl Lahti’s challenge as my relief, after.”

In the big picture of the base’s operations, the furloughs are very small. The main issue is that the sequester represents what nearly everyone agrees is a ham-handed way to control costs.

The base, home to 15 nuclear subs, has an estimated economic value to the state of $4.5 billion, including all direct spending, indirect spending and spillover effects as the money courses through the state’s economy. That figure might be a bit of an exaggeration and it might be on target, but either way, it’s far more valuable to the economy than, say, retail spending because virtually all of the money is coming from out of the state.

More broadly, the possibility of a Base Realignment and Closure Commission, or BRAC, represents a threat to the base — which was on an initial list of targeted bases in 1993 and again in 2005, but was saved both times. President Obama has requested a BRAC for 2015 but that’s not likely to happen based on the chilly reception in Congress, said Bob Ross, executive director of the state Office of Military Affairs.

The House Appropriations Committee not only nixed the idea in its version of the budget, it prohibited the Pentagon from preparing for a BRAC, Ross said.

Connecticut is a lot better prepared this time around in case of a base-closing commission, as the Pentagon has spent $150 million upgrading Groton and the state has spent another $11 million.

“The nation has to do BRAC, there’s no doubt about it,” Ross said Wednesday, but not during sequestration and other defense cutbacks, and not before the Pentagon studies the effects and the lack of savings from the 2005 round.

As for the sequester, Ross said, “It’s going to pop up in places where you don’t expect it.”