Make no mistake: Mayor-elect Zohran Mamdani’s vow to not shut down homeless encampments threatens to turn the city into an unsafe dump.

It’s an amateur’s promise, driven by abstract ideas completely at odds with the grim realities of the streets.

Mamdani on Thursday offhandedly rejected the city’s longstanding policy of clearing makeshift settlements out of public areas, preening, “If you are not connecting homeless New Yorkers to the housing that they so desperately need, then you cannot deem anything you’re doing to be a success.”

If he doesn’t wake up, homeless camps will grow and fester all across the city, not just in underpasses but in parks and other open spaces in every neighborhood.

The left imagines that if the city offered housing to every person on the street, homelessness would disappear.

The reality is that most street homeless spurn the shelters: They’re drug-addicted, mentally ill or both — and actively reject reintegration into society.

Progressives slam Mayor Eric Adams’ encampment-clearing approach, which City Hall says has connected 500 people with “safe, stable housing,” because the vast majority of the cleared-out homeless remain on the streets.

But that’s because many homeless refuse to enter the shelter system, and the city can’t force them in.

Clearing the encampments keeps them from growing into the permanent shanty towns that plague cities like Los Angeles.

It also gives the homeless an incentive to take the city up on offers for shelter and services.

The alternative is to leave them to rot in shoddily built structures made from tents, tarps and garbage: Surely Mamdani doesn’t see that as a more compassionate course?

It also inflicts intolerable costs on surrounding areas: Open drug use and human misery flourish in and around the camps; crime of all kinds inevitably springs up around them as decent people steer clear.

There’s no better way to blight a neighborhood.

New Yorkers have been loud and clear that they don’t want dangerous homeless villages near their homes, schools and churches; this year alone has seen 45,000 camp-related 311 complaints — and that’s with the city trying to clear encampments as fast as they form.

If the mayor-elect doesn’t backtrack on this lunatic pledge, he’s guaranteeing soaring public disorder and filth: Skid Rows in neighborhoods and parks across all five boroughs.

Whatever the past failures of enforcement, no mayor has ever declared such camps to be kosher.

Put ordinary New Yorkers first, sir: Don’t let street homeless take over whole swathes of the city.