Though much of Calgary remains underwater, including parts of an eerily quiet downtown, some of the 75,000 flood evacuees are being allowed to go back home.

Residents of Hillhurst, Bridgeland, Discovery Ridge, Quarry Park, Riverbend, Douglasdale and Deer Run were given permission Saturday to return to their homes.

"We're hopeful that we'll get three more neighbourhoods, or portions of those three neighbourhoods, back tonight," said Calgary Mayor Naheed Nenshi at a press conference on Saturday.

The city is still in a state of emergency, but they are aiming to reopen six neighbourhoods, maybe more, said Calgary Emergency Management Agency director Bruce Burrell.

The city added an area of "restricted access" downtown from 12th and 11th avenue, from 14 Street West to Centre Street, after initially reporting that it was expanding the evacuation zone to that area.

Calgary officials also banned the use of water outdoors and both the Calgary Board of Education and the Calgary Catholic School District have cancelled schools for Monday.

Calgary Mayor Naheed Nenshi said the Bow and Elbow rivers are in a gradual decline.

City officials were also told that the river levels were four times what they were in 2005, the last time the city saw intense flooding.

Neighbourhoods that did not sustain water damage will be opened in portions as the city works to reopen roads and get utilities working.

"Only make an attempt to return to your home if you have clear messaging from the City of Calgary that that area has been opened up and it's safe to do so," said Burrell.

"If we have convergence of a lot of people trying to return early, it will put a strain on our resources, the roads will become congested and it will become much more difficult to re-enter in an organized manner."

As the sun rose over much of the city Saturday morning, the Elbow River is coming steadily down, and the Bow is seeing improvements, too, said Burrell.

However, it's too early to tell exactly how much damage the flood will do to local infrastructure.

Video shot by CBC reporter Alana Baker appears to show a crumbling pathway along the Bow River near Memorial Drive and 18th Street N.W. on Saturday.

It's not clear whether this is the only crumbling pathway in the city.

Downtown power could be off for days

Downtown could remain closed for four to five days as roads are heavily flooded, said Burrell. Much of the core does not have power.

Crews are racing to pump water from substations and restore electricity to neighbourhoods, but repairs and necessary work to dry out, then test equipment inside power stations means the downtown area may be left in the dark until the middle of the week.

"When I came here this morning, when you looked down in this area, all you saw was darkness," CBC's Terry Reith said, standing above the former parking lot of the Calgary Curling Club, now submerged in the murky waters of the Bow River.

"Now you can start to see some of the damage and the impact of the water — up to the bumpers of cars," he said, showing an overhead view that also revealed an abandoned police cruiser.

At one point, water in the Saddledome arena, home of the Calgary Flames, was reported to have risen up to the 10th row of seats, causing millions of dollars in damage.

Speaking on Saturday, Flames CEO and president Ken King acknowledged the damage to the facility was extensive

"It's a total loss on the event level," he said. "The stage is floating, the dressing room is totally submerged ... Everything that happens on the event level is gone."

The Calgary Stampede grounds were also flooded from the deluge that has claimed at least three lives in Alberta. The Stampede is scheduled to take place in just two weeks.

The worst of the rainy weather appears to be over for Calgary, however, and residents in the community of Discovery Ridge learned this morning that some were given the go-ahead to return to homes that are on higher ground.

175,000 Albertans under evacuation orders

Residents in southeastern regions of the province are now bracing for possible floods, particularly in the cities of Medicine Hat and Lethbridge. The Bow River from Calgary and Oldman River from Lethbridge meet to form the South Saskatchewan before heading on to Medicine Hat.

Medicine Hat is in a state of emergency. Officials now say they expect the river will peak on Monday.

David Sands, a spokesperson with the government of Alberta, said that 23 communities were still under states of emergency as of this morning.

Officials in Red Deer say that a flood warning is still in effect for that city because it's not clear whether peak water level has been reached.

Confluence of factors led to flooding

Torrential rain last week — up to 200 millimetres in some places — as well as saturated ground and the local geography that encourages water to run downhill quickly were among a confluence of factors leading up to the devastation.

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The RCMP say at least three people have died in the floodwaters. Their bodies were discovered in the Highwood River in the community of High River.

That community, just south of Calgary, was one of the hardest-hit areas. It is estimated half the people experienced flooding in their homes. Roads and bridges have been swamped, police have cut off access to most of the town and helicopters have been circling overhead. Cars lie submerged in water, abandoned, while backhoes work in vain to push water back from houses.

Prime Minister Stephen Harper, a long-time Calgary resident, met with Alberta Premier Alison Redford and Nenshi to visit the city’s Emergency Operation Centre on Friday.

"I never imagined we could have a flood of this magnitude in this country," he said.

"The magnitude is just extraordinary. It is stunning."

Most officials are not speculating how long it will take for the rest of the evacuation orders to be lifted in the city.

"In Calgary, it doesn't look like it has receded very much and in fact there is some danger that the Bow River, which is already extremely high, could rise a little bit more as more of this water works its way down from the mountains," Reith reported from Calgary.

Several substations that supply the downtown area were swamped. That water must be pumped and the equipment must be dried before the stations are fired up again.

B.C. government offers to help

The provincial government in B.C. extended an offer of help to Alberta on Saturday.

Emergency Management B.C. made the official offer to support response and recovery efforts on behalf of the B.C. government.

It's expected that, if accepted, the offer could include mobile medical units, additional ambulance support, co-ordinating road condition information on B.C. websites and relocating Calgary Zoo animals to the Vancouver Zoo, if necessary.

The government may also send damage assessment teams and could put forward a variety of health care professionals and support management teams.

It's not immediately clear when those teams could be on the ground in Alberta.