The Bissell Centre was forced to close after a storm on Monday caused a sewer to back up and flood the basement of the inner-city agency.
"It's worse than we thought it would be," CEO Mark Holmgren said Wednesday. "We thought it would be a week or two. Now they're talking a month to two months."
The closure means the city's less fortunate are unable to use the agency's services.
"We have no access not only to the kitchen but to any of our food that's down there, any of our supplies that are down there," Holmgren said.
"We have no way of giving away clothes that are down there in fact most of the clothes will be destroyed because of contamination."
Anyone who wishes to help the Bissell Centre can do so by donating cash or gift cards, Holmgren said
Buildings all over Edmonton have been flooded during storms that have dumped heavy rain on the city over the past couple of weeks. City officials say the weather has had an effect on drainage systems.
"If only the rain would stop for a couple of days and let the system drain out, we'd be OK," said Transportation general manager Bob Boutilier. "But it just keeps coming day after day."
However, officials dismissed any suggestion the system is incapable of handling the heavy rain.
"No, I wouldn't say that at all," said Sid Lodewyk, acting director of drainage operations. "I think what you see is it's actually quite performing quite well."
Lodewyk said many of the flooding problems can be traced to property owners, not the city.