This weekend, The Washington Post ran an editorial in support of what it called “a pretty sensible idea”: building a giant parking garage under the National Mall. The concept comes from the “energetic and civic-minded nonprofit” National Coalition to Save the Mall and envisions a facility stretching from 9th Street to 12th Street NW and containing a garage, bathrooms, and rainwater collection.

Post editorial page editor Fred Hiatt tells my energetic and civic-minded colleague Will Sommer that this is not an April Fools joke, so I’ll take it seriously. Or as seriously as it merits.

There’s nothing inherently awful about the idea, except that it’s a solution in search of a problem. When I have visitors in town on the weekend and we drive down to the Mall to visit the museums, I’ve never had the slightest trouble finding parking within a block or two of my destination. During the week, we certainly don’t want to encourage more downtown workers to drive to their jobs—-not when traffic in the area is awful as it is and four of the five Metro lines stop within a block of the Mall.

Rainwater collection and extra bathrooms are all well and good, but can they possibly justify an expense of hundreds of millions of dollars and years of construction on the Mall, which is already constantly phased out of use for upkeep? That’s not to mention the likely concerns of the National Park Service, which prevented a Metro entrance on the Mall and probably wouldn’t be wild about a parking garage under it.

Mayoral spokesman Pedro Ribeiro apparently told the Post that the plan would help solve the city’s tour-bus parking problem and was “intriguing and worth further exploration.” I couldn’t immediately get a hold of Ribeiro, but the idea of building a giant underground parking lot under the National Mall in order to stash a few tour buses seems like overkill, to say the least. Let’s hope city officials won’t spend too much money or time exploring it.

That is, if Hiatt and company aren’t just pulling our collective leg.

Renderings from savethemall.org