"We have one to three feet of water in our basements," Paulette Gagnon, director of the Montreal museum of contemporary art, said Wednesday.
"Part of the basement holds our reserves so of course some of our reserves were damaged."
Between 50 and 75 millimetres of rain fell in a half-hour Tuesday evening, causing water and sewage to erupt from some city manholes. One line of the subway system was shut down as water poured into stations, an expressway was flooded and homes and businesses reported torrents of water pouring into their basements.
Montreal Mayor Gerald Tremblay said Wednesday that city workers were prepared for the deluge and pointed out that no sewer system could have handled that much of a downpour in such a short period.
"The experts are unanimous in saying that if we had not invested the money we have invested in recent years — more than $1 billion dollars — the consequences of this deluge would have been worse," Tremblay told a news conference.
One hard-hit area was Montreal's downtown, including the Place des Arts complex, where the museum is located.
Gagnon said Wednesday it is still too early to say the extent of the damage or its cost but she says most of the objects can be repaired.
"It's a lot of work, a long process," she said in a telephone interview. "It's not a dozen works, it's hundreds. But we still don't know the exact number. We don't know the total losses. We still have to make an evaluation."
This is the fourth time the museum has seen serious flooding, which has been blamed on a drainage problem. Gagnon said this is the worst, however, "because it's the largest number of works that have been affected."
A special cleaning and decontamination team has been at work in the museum since Tuesday night and are expected to take at least a week to complete the task.
Gagnon said a solution must be found to the problem so a similar incident won't happen again.
"It doesn't make any sense," she said. "It's a museum. It can't be flooded every time there is a downpour.
"It's part of our heritage ... we have to protect it and put it in a secure place. That's why museums exist and if our basements aren't adequate then there's a big problem."
The extent of the damage caused the museum to cut short one exhibit. It was not damaged by the flood but it was located in the basement where the cleaning crews are working. Another event planned for Friday has also been postponed.
Tremblay said the city is also taking stock of the damage on its territory and pointed out the emergency 911 line had gotten 961 calls within minutes, including 98 for floods and 94 for accidents.
Officials which oversee the city's sewer system said they were surprised by the power of the storm on the system, saying the pressure buildup had popped some welds that had be done to repair certain pipes. Tremblay said the city would be reviewing the system's capacity.
(With files from Pierre St-Arnaud)
Note to readers: This is a corrected story. A previous story referred to the museum as the Montreal Museum of Fine Arts