Patients set to have surgery this week at the Misericordia Hospital are being rescheduled after a thunderstorm caused flooding at the aging facility early Saturday morning.

About 300 patients are affected. Some procedures will be moved to other parts of the hospital; others will move to the Grey Nuns Hospital in Mill Woods.

“Our operating rooms themselves have not been impacted,” said senior operating officer Jan Schimpf.

“It really is about our sterile supply area was impacted and that area will be up and running and fully functional by Monday.”

An internal email to medical staff obtained by CBC News, says that there was extensive damage to the floor in the surgical day ward, endoscopy and cystoscopy areas and repairs are expected to take 8 to 10 weeks. 

The hospital is trying to get the sterile storage set up by Monday. 

"For those of us who have lost OR time, there are no plans in place yet to make up this time," the email says. 

Cory Paterson was supposed to travel from Lethbridge to Edmonton next week for a follow-up appointment at the Misericordia.

He called the hospital on Monday to find out what was happening.

“They said it's going to be about eight to ten weeks before ... they can get back on track with surgeries and whatever else,” he said.

This isn’t the first time the Misericordia has been affected by flooding.

In May 2013, the hospital had to cancel 46 elective surgeries and move 53 patients after valve ruptured while a toilet was being repaired.

Staff felt that problems at the 45-year-old hospital were so acute that they spoke out about the deficiencies earlier this year.

Critics say the government isn't doing enough.

“It's unacceptable,” said Friends of Medicare executive director Sandra Azocar. “We do not live in a third world country and we should not have to have those situations happening.”

Liberal leader Raj Sherman said the situation at the Misericordia compounds problems elsewhere in Edmonton. 

“If the Misericordia can't serve the needs of the citizens in the west end, it impacts every other hospital and every other emergency department in the city,” he said.

On Sunday, Health Minister Fred Horne said a new facility is on the horizon.

“Covenant Health is providing me, along with AHS, with an estimate in the next five to eight years of how much additional funding they might require to keep the hospital running at capacity while we build new hospital capacity in Edmonton,” he said.

In the meantime, fans have been set up to dry the areas that flooded.  The hospital doesn’t yet have a damage estimate.