NEW YORK — Up and down the streets of Chelsea, imposing gallery doors that are traditionally closed have been propped open. Dealers and art handlers are running in and out of galleries, piling the sidewalks high with debris and packing up artwork in crates. Gallery owners like Andrew Kreps, whose space is located aboveground on 22nd Street, have made their venues available to neighbors in need of a dry place to survey soaked inventory. The extent of the damage caused by Hurricane Sandy, most said, will take days to process and months to repair. “All of Chelsea has to rebuild,” a weary Leo Koenig told ARTINFO.

Though it is difficult to determine precisely how much artwork was destroyed during the storm on October 29, a tour of Chelsea reveals almost every space below 25th Street sustained some sort of flood damage. Inside Eyebeam, the art and technology center on 21st Street, water remains at least three inches deep. One block up, at Carolina Nitsch Gallery on 22nd Street, several wooden chairs dating from Qing Dynasty China — part of a larger installation by Ai Weiwei previously displayed at Documenta XII in Kassel, Germany — have toppled over; water stains are visible on the ground.

A few doors down, at Matthew Marks Gallery, Tony Smith’s 12,000-pound angular sculpture, “Source,” bears a watermark two feet high all the way around. Art handlers were preparing to move it out of the gallery on Wednesday morning; employee Ed Spurr said he wasn’t too worried about the sculpture because it is an outdoor work.

Spurr, however, was in the minority. “Almost everyone lost some art,” said Adrian Turner of Marianne Boesky Gallery. Even spaces located above street level, like D’Amelio on 22nd Street, experienced flooding up to three feet high in their basements. An employee of that gallery confirmed it had lost some artwork despite the fact that its main exhibition space was unharmed. Over at Nicole Klagsbrun on 24th Street, “artwork was literally floating around,” said Patrick Brennan, an artist and employee of the gallery. Passing Bortolami Gallery on 20th Street, this reporter spotted a green-and-white fabric panel by Daniel Buren propped against the wall on top of two chairs. A watermark about one fifth up the canvas was clearly visible.

How could professionals whose livelihood depends on material inventory have been so unprepared? Some dealers said they didn’t anticipate the extent of the storm. Koenig sprayed the interior of his gallery with protective foam as high as 28 inches, but it “simply wasn’t high enough,” he said. Though he stored most of the gallery’s inventory out of harm’s way (“we only lost a few pieces of sentimental value,” he said), the water damage will require “weeks and weeks” of construction. “I came down here at around 5:30am yesterday, and I was pretty devastated,” he admitted. “Now, I suppose, we can switch offices, and remodel the place a bit. It smells like a rainforest in there.”

Dealers who stored their artwork off-site in advance of the storm must still must repair damage to their infrastructure. “I have no idea when we’re going to get a contractor,” Franklin Parrasch, who runs a project space on 22nd Street and a larger venue on 57th Street, told ARTINFO. Though his entire inventory was safely tucked away in his uptown gallery during the storm, “the water that entered the Chelsea space is very contaminated,” he said. “It has to be cleaned, sanitized, and the walls will have to be rebuilt.” The gallery will be closed for “about a month,” he estimated.

Even in the face of waterlogged basements and stained walls, however, dealers are dealers — they can’t help but think about their next show. Piling trash outside his gallery on 22nd Street, Zach Feuer told ARTINFO he was hoping to put up a modified version of his current exhibition — works on paper by artist Kate Levant — in a temporary space in the coming weeks. It will probably be somewhere uptown.