A CP train track collapsed into a flooded creek in Medicine Hat during heavy rain. ((Submitted by Debbie Holick))

Medicine Hat and other parts of southern Alberta are bracing for more flooding after a state of emergency was declared and hundreds of homes were put under a voluntary evacuation order.

People in at least 200 homes in a neighbourhood known as the Flats were encouraged to leave on the weekend as the tributaries of the South Saskatchewan River continued to rise.

"The major concern now is for another front that's coming in that will settle Monday into Tuesday over the Cypress Hills and that will bring a further 50 to 70 millimetres of precipitation," said Colin Lloyd, spokesman for the Emergency Management Agency.

"Field officers are on the ground sandbagging and educating residents about how to keep themselves and their belongings safe."

States of emergency have also been declared in Lethbridge, Cardston and Coaldale.

The Trans-Canada Highway between Medicine Hat and the Saskatchewan border remained closed on Sunday and officials were not sure when it would reopen.

The normally arid area has received a tremendous amount of rain, which has caused creeks to overflow their banks and storm drains to back up onto streets.

'I'm still unable to describe the destruction and devastation that has occurred … I've seen videos on disasters like this. I've never see it up close like that.'

— Dwayne Johnstone, Irvine deputy fire chief

People in Medicine Hat grabbed animals and packed suitcases and headed for local hotels or to stay with friends and family.

The city warned late Saturday that anyone staying behind in the Flats should avoid using their water to drink or brush their teeth.

The provincial environment minister and officials who flew over the flooded area on the weekend said the devastation appears significant enough to qualify for disaster relief funding.

The decision would be up to cabinet, they said.

Floods destroy homes, crops, livestock

Meanwhile, residents of Irvine, Alta., say their homes are filled with muck from the floodwaters — and with rain in the forecast they're bracing for even more flooding.

Blaine Riedlinger, captain of the Irvine Fire Department, estimates 40 residents were forced from their homes, four of whom are staying with him.

A farmyard sits underwater after flooding in Irvine, Alta. ((Jeff McIntosh/Canadian Press))

"The flood has totally wiped out some people's vehicles, their livestock, of course, from chickens to wiping out the cattle around here, and of course our crops, so [it's] drastic around here," he said.

Karen Kramer was out in her garden when water started rushing towards her home. She said it was like a flash flood.

"It was just horrible," Kramer said. "The whole block, all the homes around the area near this slough and along the highway were just filled with water."

Kramer said the main floor of her home was filled with about seven inches of water and mud.

Deputy fire chief Dwayne Johnstone and his wife are among those forced from their homes. He said the forecast for more rain is a big concern.

"I'm scared," he said. "It's got me a little nervous. I think that we need to be prepared in case more flooding occurs."

Johnstone said the flooding is unlike anything he's ever seen.

"I'm still unable to describe the destruction and devastation that has occurred," he said. "It was that bad. I've seen videos on disasters like this. I've never see it up close like that."

With files from The Canadian Press