By Scott Haggett and Nia Williams
CALGARY, Alberta, June 24 (Reuters) - Calgary will push ahead with its annual Stampede festival on July 5, a marquee event that draws a million people, despite massive flooding that swamped the venue and left the downtown of Canada's oil capital without power, officials said on Monday.
The worst flooding in decades late last week turned streets in Calgary and other towns in southern Alberta into fast-running rivers, wreaking damage that will likely cost billions of dollars for repairs and clean-up operations.
The Stampede, a 10-day bonanza of rodeo, street parties and corporate entertainment, pumps C$340 million ($320 million) a year into the economy of Calgary, Alberta's largest city.
"We're going to do whatever it takes to be ready by July 5," Calgary Stampede Chief Executive Vern Kimball told reporters, promising that volunteers would accelerate their schedule to get facilities ready in time for the event.
City officials said on Monday they expected to reopen downtown Calgary over the next two to three days, but the city's mayor has urged companies to encourage employees to work remotely for several days.
Missing out on income from the Stampede would only increase the economic impact of the flood, which is already sure to be far greater than the C$400 million in damages caused by the "flood of the century" of 2005.
BMO Capital Markets said the latest deluge could cut Canadian gross domestic product by 0.1 percentage points in June, at a conservative estimate, while total losses could be C$3 billion-C$5 billion.
Alberta Premier Allison Redford promised C$1 billion in initial funding to help pay for damage, some of which will be covered by the federal government. Some repair work could stretch out over a decade, she said.
The flood swamped part of Calgary's downtown core, home to the headquarters of most of Canada's oil and gas industry, where power is likely to be out for days or even weeks in some pockets. It also forced about 10 percent of the city's 1.1 million residents out of their homes.
In communities south of Calgary, floods killed three people and also forced evacuations and plant closures.
The floods temporarily halted the movement of potash, an important fertilizer, from mines in the next-door province of Saskatchewan to West Coast ports and shut a big beef processing plant and a fertilizer plant. But companies said they did not expect the disruption to last long.
Officials said about 65,000 Calgary residents had now returned to the houses they left on Friday after the Bow and Elbow rivers spilled their banks.
Homeowners piled damaged furniture and other garbage on front lawns and at curbs and used snow shovels to push layers of silt into already grimy streets.
"We are selling lots of mops, lots of pails, lots of garbage bags," said Keith Attrill, assistant manager at a Home Depot store. "It's the initial clean-up. We are much busier than normal."
Toronto contractor Mike Feldstein said he flew to Calgary two days ago, and has six trucks loaded with supplies on their way.
"We had an apartment today where it was mud and sewage everywhere. The first floor was destroyed. The laundry machine was on its side, fridges were tipped over because they had been floating down the hallway," he said. "People are devastated."
Sorting out its transit problems is among the many issues that Calgary will have to tackle in short order to prepare for the Stampede. News photos showed buckled, twisted tracks on the transit line that services Stampede Park.
John Jackson, executive director of the Calgary Hotel Association, said nine downtown hotels were still without power, but there was no major water damage.
Although oil company headquarters in Calgary were closed, traders monitored the crude market remotely.
"We are all working remotely using iPhones and BlackBerrys," said one Calgary-based crude trader, who expected volumes to be very thin. "Other than not being able to stand up and holler across the desk, it's fairly normal."
However, oil pipelines that move almost 1 million barrels per day of Alberta oil sands crude remained shut after a spill on a smaller line that may have been caused by the flooding in the southern part of the province..
Suncor Energy Inc, Canada's largest oil company, said late on Monday it has temporarily reduced output from its Fort McMurray operations because of the precautionary shutdown of the Enbridge pipeline system within the Fort McMurray region.
The company said it is using its existing storage capacity, as well as moving volume on its oil sands pipeline, while it works with Enbridge to bring its pipelines back into operation.
Canadian Pacific Railway said its main line west of Calgary had reopened after crews restored portions of the track that had been hit by the floods.
But the TransCanada Highway, Canada's main east-west road link, was still partially closed at Canmore, Alberta, a resort town that is a gateway to the Canadian Rockies.