Jacksonville taxpayers have forked over $47 million to keep three downtown parking garages afloat, a subsidy that amounts to about $16,637 per space — and rising.

The fallout is expected to get worse, according to the Florida Times-Union, because the city is on the hook for financial shortfalls at the garages until 2030. The situation should be a cautionary tale for cities thinking of subsidizing downtown parking structures.

The garages were part of the “Better Jacksonville Plan” approved by voters in 2000, which funded the construction of a county courthouse and the Jacksonville Veterans Memorial Arena with a half-cent sales tax increase.

In 2004, the city inked a deal with a garage operator. The public commitment for one 1,375-space structure by the courthouse plus 1,000-space and 480-space garages by the arena was supposed to be limited to $19 million, with the garages turning a profit by 2019. But that’s not how things worked out.

The garages are only producing half the revenue projected in 2004, reports the Times-Union’s David Bauerlein, and the city must make up the difference. Jacksonville has to pay off debt incurred by garage construction and cover a contractually guaranteed 6.75 percent rate of return for the private operator. Each year, taxpayers fork over about $3.8 million to pay off the garages, and there’s no stipulation allowing the city to renegotiate terms before 2030.

It’s too late to salvage this deal, but maybe Jacksonville will avoid making the same mistake in the future. Subsidized parking is a bad bet, even in car-centric Jacksonville, which is now short $47 million it could have spent to improve walking, biking, and transit instead.