Days of rain and thundershowers are expected through the end of the work week for a region of B.C. already partially submerged.

Water levels have been rising for several days in parts of the southern Interior, swallowing vehicles and even homes as the rivers surge due to sudden heat and rapid snowmelt.

But the those installing sandbags and other flood barriers were previously working under clear skies. The region clouded over in some areas Wednesday, and the rain is expected to stick around until the weekend.

As a result, Environment Canada has issued special weather statements for the Okanagan Valley, Arrow Lakes-Slocan Lake, Boundary, East and West Kootenay, Kootenay Lake and Elk Valley areas. The statements warn of a total rainfall amount between 20 and 40 millimetres by late Friday. 

Some areas, including the Kootenays, could see brief but heavy thunderstorms Wednesday night, the weather agency said. The storm risk will then spread west to the Okanagan by Thursday afternoon.

But the trouble began long before the first drop of rain fell in the community of Christina Lake.

Bubba and Liz Brandt, a couple from Trail, took CTV News on a tour of the submerged park where they keep the mobile home they stay in during summer months. As their boat travelled down streets hidden under hip-deep, brown-green water, they pointed out the damage caused to their home and those of their friends.

"We had fish swimming up on the deck here," Bubba said as he pulled the boat while wading through the water.

"The water has never gone up this far. It's actually gone down about six inches but they're saying that there's going to be another surge."

"It's devastating. We've been coming here decades," Liz said.

Bubba said his kids, aged 17 and 21, grew up in the park now filled with water. His father, aunt and uncle, and several of his friends own mobile homes in the park, and he recalled 50-person barbecues held outside in the summer.

"We would have never thought we'd be sitting in a boat," he said.

But he added that their experience paled in comparison to the situation a short drive west of the park in Grand Forks. While they're dealing with damage to their summer homes, in the city 12 kilometres away, people have lost much more.

"The people in Grand Forks… My heart goes out to them."

Those living in the city of roughly 4,000 are hoping to get military assistance as they brace for a second round of potentially catastrophic flooding this week.

Hundreds of residents attended a community meeting about the flood preparations Tuesday night, and let out a loud cheer when local officials revealed they had requested military help. There's no word on when – or if – that request might be approved, however.

Emotions ran high at the meeting, where desperate residents were able to question local and provincial officials about their flood response measures. Grand Forks Mayor Frank Konrad offered some reassurance to people whose livelihoods have been affected by the disaster that compensation will be coming.

"Can these people that now have contaminated land and lost their house, are they going to get zero value for that? Absolutely not," Konrad said. "They have to be compensated. They cannot walk away with nothing. And (B.C. Premier John Horgan) gave me that assurance."

Dozens of homes in the community have been badly damaged or completely lost by flooding.

Residents are hopeful that the military will be sent in to help with sandbagging and other property protection efforts to prevent further destruction.

Local volunteers have been sweating in the sun day after day filling tens of thousands of sandbags, and on Wednesday groups of elementary school children were let out of class for an hour at a time to help out.

Later in the day, School District 51 decided that all of its schools would be closed Thursday due to potential flooding and road closures.

And while they know it may not be safe to stay behind during flooding, evacuees are reluctant to leave after being targeted by criminals.

Mounties confirmed several suspects have been arrested in connection to a string of thefts at evacuated properties. One resident told CTV News her neighbours had their all-terrain vehicles and two trucks stolen, but fortunately police caught the crooks.

"People are destroyed here," the woman named Merla said.

"And they just get you when you're down. I hope they don't loot me. I'll have to protect myself."

There is now a visibly heightened police presence in the area, with members of various RCMP detachments around the province being brought in to keep watch.

With files from CTV Vancouver's Sarah MacDonald and Ann Luu