The Department of Education has allocated well over a quarter billion dollars to cover gaping school budget deficits tied to ongoing student enrollment declines, The Post has learned.

The DOE will give city public schools a total of $323 million dollars this year to help them cover basic costs — including teacher salaries, according to a memo released last week.

The mammoth expenditure “allocates funding to schools in order to offset budget declines resulting from the SY 2021-2022 mid-year adjustment,” according to the agency.

Since funding is calculated by student population, principals confronted with steep drops are unable to meet costs without additional funding.

“There are a lot of schools that have lost entire chunks of their enrollment,” said a DOE source. “That means a lot less money for the principal. So they are basically covering the salaries of teachers who they don’t necessarily need this year.”

The memo states that 78 percent of the $323 million is drawn from the city while the remainder comes from federal coronavirus relief funds.

A total of 25 schools are getting more than $1 million each to account for eroding registers, according to the document. The vast majority of schools are receiving six-figure sums.

Fort Hamilton High School in Brooklyn was by the far the highest recipient at just under $3.5 million. The school has lost nearly 400 students this year, according to state data, or 8 percent of its total population.

Some of the city’s most prominent schools also saw seven-figure budget allocations to make up for exiting families.

New Explorations in Science Technology and Math in Manhattan, a citywide Gifted and Talented campus, is getting over $1.2 million to replenish its coffers, documents show.

Enrollment at the traditionally coveted campus has dropped by nearly 9 percent this year, going from 1,797 to 1,639.

LaGuardia High School, the city’s famed performing arts bastion, saw enrollment skid by more than 12 percent this year and will receive almost $1.25 million to cover costs.

While schools are being made whole this year, DOE sources said enrollment declines could soon force principals to shed teachers.

“This is going to be a labor issue very soon,” said a former DOE senior executive. “They can’t keep holding these salaries up forever, the funds are going to dry up.”

Overall, K-12 traditional public school enrollment has dropped by 5.6 percent this year to 821,000 kids, according to a compilation of state data from the education news site Chalkbeat.

The outlet reported that 23 percent of city schools lost at least 10 percent of their kids this year.

“We are pleased that we are able to provide, with support from federal stimulus, funds to schools to help compensate for COVID-related enrollment fluctuations,” said DOE spokesperson Jenna Lyle.

Some observers theorize that families who left the public schools system or the city during the pandemic could return if conditions stabilize.