Every so often, this old chestnut reappears: To solve its parking problems, Washington should burrow garages beneath the downtown parks and squares.

The idea first came up in the late 1920s when planners, perceiving a parking crisis, suggested also that the interior courts of buildings then being built in the new Federal Triangle be turned into parking areas. It came up in the 1930s when members of Congress suggested garages under Farragut and Franklin squares. It came up in the 1950s when, partly as an alternative to a subway, a gigantic garage was proposed beneath the Mall -- but was resisted mightily by the National Park Service. And it came up in the 1960s when the Architect of the Capitol proposed a garage beneath the East Front of the Capitol itself.

Now the idea has come up again in the wake of the White House's outrageous commandeering of part of the Ellipse to park employe-owned cars that, if they must be parked in the neighborhood, should be parked at the employes' expense in nearby commercial garages.

Insurance executive August P. Alegi, writing as president of the National Capital Transportation Federation, has suggested that a government agency -- he doesn't suggest which one -- should build a huge garage beneath the Ellipse to accommodate not only White House employes but tourists, shoppers and other "commuters who must use their cars."

The environmental impact would be lessened, he suggested, by putting the exit and entry ramps on 15th and 17th streets. But wait! Those ramps would surely consume far more space and do greater visual damage to the Ellipse, not to mention adding to the downtown traffic volume, than the entire, supposedly temporary lot occupied by White House cars. Anyone who doubts this should look at, for one example, Union Square in San Francisco, where the ramps overwhelm the landscape.

A piquant footnote. It was 50 years ago last month that Rep. Everett McKinley Dirksen (R-Ill.), then a second-term member of the House (and at his death in 1969 the Senate minority leader), proposed the garages beneath Farragut and Franklin squares. They would be financed, he suggested, by fees collected from the owners of parked cars -- not to exceed 10 cents a day. The Right Word

Recently, on a bleak day much like yesterday, Metro Scene suggested that a time would soon come when our "greatcoat and the overshoes go into closet hiberation" for the season.

That brought a brief note yesterday from Dorothy R. Gates of Washington. The wintertime items, she suggested, will go into "estivation."

Estivation? Darned if she isn't correct. That means "to spend the summer," while "hibernation" means "to winter." However, a secondary meaning of hibernation is "figuratively, to retire into, or remain, in seclusion," regardless of season.