Great news: Forget the recession — City Hall is rolling in dough.

That’s how it might seem, anyway — based on the plan Mayor Mike announced last week to spend a whopping $50 million on the city’s community colleges and their students.

The truth?

“Tax revenues have evaporated,” City Comptroller Bill Thompson noted in a recent analysis.

Revenues are expected to fall $1.56 billion this year. Personal income-tax receipts will be off more than 30 percent from two years ago. City Hall faces a $5 billion hole in next year’s spending plan, which it must close in five months.

The city has “struggled to maintain budget balance,” Thompson says.

So how will Mayor Mike — who pitches himself as a meticulous fiscal steward — come up with the extra $50 million for the colleges?

Actually, he has no clue.

His campaign team developed the plan and apparently hopes some of the money will come from a $12 billion initiative by President Obama for two-year schools. The rest would come from private sources — and the city budget.

But, again, the cupboard’s bare.

And Mike’s already raised property and sales taxes. Is this how he plans to use the new tax revenue — even as he cuts cops and other key services?

And make no mistake: The $50 million is just a down payment: The plan, for instance, calls for a new 5,000-student community-college campus in Manhattan — but allocates just $2 million for it.

Two-bedroom co-ops in Manhattan go for more than that, even with real estate depressed.

Yes, we know: Mike’s running for re-election, and this plan is aimed squarely at “working women, middle-class workers in need of retraining and . . . hard-working immigrants.” Key voters, that is.

And, yes, there are worse ways to spend taxpayer money. (Congress’ “stimulus” outlay of $3.4 million for a turtle tunnel in Tallahassee comes to mind.)

But a coming election is no reason to promise funds for a new program when the city is facing such tough fiscal times.

Mike, if anyone, should know that.