Target Field's financing relies on Hennepin County sales taxes. We all know retail sales are in the toilet; car sales are past the wax ring.

So is the ballpark's financing in danger?

Not much.

Hennepin County needs roughly $1.7 million a month — about $20 million a year — to pay off ballpark bonds. Here's how receipts tracked for the six most recent months:

May: $2.3 million
June: $2.4 million
July: $2 million
August: $2.9 million
September: $2.6 million
October: $2.6 million

It's an interesting window into local economic activity; remember, the ballpark tax is 0.15 percent, or 3 cents on each 20 bucks.

The Republican National Convention boosted August and September receipts, notes county spokeswoman LuAnn Schmaus. But the economy's plunge was in full force in October, and Hennepin's number held firm.

County finance director David Lawless says there's "a fair amount of monthly variation" in sales-tax receipts, but the county has a fairly sizable cushion. He estimates 2009 debt service at $19.6 million; the county collected $28 million in 2008.

Therefore, 2009 collections could fall a calamitous 30 percent and still fully fund debt repayment. There are reserves, too, though I didn't fully grasp the exact numbers there. [Update: Lawless says these reserves are currently $8 million.]

However, fans of youth sports and county libraries might be just a wee nervous. The ballpark bill allows the county to direct up to $2 million annually to each area — provided there are excess tax collections. Lawless said they would be "the first things to go" if receipts plunge precipitously.

Again, he doesn't think this will happen. [The $8 million in reserves can fund both programs if necessary.] Back-of-the-envelope calculations say it would take a 16 percent sales drop, which is still a historically large decline.