Three B.C. communities Squamish Mount Currie and Prince George issued states of emergency today as flood waters continue to rise to near record levels.

More than 50 homes were evacuated in Terrace, Smithers and Mount Currie, and thousands more throughout the province placed on alert, as rivers overspilled their banks and threatened homes and livestock.

The biggest flood threat is in Smithers and the Kitimat-Stikine Regional District, where up to 400 homes are at risk, while the Lower Mainland is expected to see the effects of flooding by Friday.

Communities such as Maple Ridge, Langley and Chilliwack have already issued evacuation alerts, while others are preparing residents to flee at a moment's notice.

"People need to be aware and concerned; you don't been to be panicking at this time but you need to be prepared," said deputy environment minister Brian Symonds.

Jim Whyte, director of operations for the provincial emergency program, said the highest level of response right now in the Skeena/Bulkley river basin, where secondary roads have been washed out, bridges closed and a cable ferry shut down because of rising waters from the Bulkley and Skeena rivers.

Rail Canada said the rising river levels in northern B.C. has also affected the Skeena train service between Jasper and Prince Rupert in both directions.

In Terrace, a mudslide, measuring 66 metres long and up to 10 metres deep, on Highway 16 has led to closures on the highway. Police say it's too early to tell if anyone is inside a vehicle found at the site, which was buried in the mudslide a week ago.

"Terrace and Smithers are certainly the focal point of our activities; that's where the flood waters are closest to the residents," Whyte said. "There's still a lot of snow left to melt."

In Terrace, about a dozen homes have been evacuated while at least one home was destroyed by flooding. More than 26 homes in the Ebenezer Flats area of Smithers have also been placed on alert.

In Prince George, which declared a state of emergency today, traffic has been restricted to local and emergency vehicles in three areas of the city: Paddlewheel Park, Pulpmill Road and River Road. No evacuation notices had been issued this morning.

"At this point, beyond that, everything seems to be under control," Public Safety Minister John Les said. "The rivers, though, are very full, flowing very rapidly, [with] a lot of debris in the rivers."

Les said officials from provincial ministries of transportation, environment and public safety are present at an emergency operations centre in Prince George.

Allan Chapman, spokesman for the River Forecast Centre, said the effects of the flood damage will depend on the weather in the next three weeks.

About 25 millimetres of rain is expected to fall in the Lower Mainland by Wednesday, with the Fraser to peak by Sunday.

"We've been at the mercy of the weather for the past month or so and it will be until the end of the month," Chapman said. "The waters will be high for an extended period of time and people should not let their guard down."

In the Fraser Valley, almost 400 dairy cows have been moved from farms throughout the province as growing fears of massive flooding continue. The provincial government issued a notice to the 48 farms identified in the "danger zones" and offered assistance to help move the 9,028 dairy cows.

As of today, 22 farms took up the province's offer and 11 have actually relocated their livestock to higher ground in Surrey, Langley and Abbotsford.

Harvey Sasaki with the Ministry of Agriculture and Lands said negotiations have begun to transport the animals to vacant farms in Washington state or to Vancouver Island where there is room for 800 animals. To minimize transmission the possible transmission of mad cow disease across the border, current laws forbid the transport of cows 30 months and older to the United States unless they are going to be slaughtered. He said negotiations are taking a while because of the need to reach a compromise.

"We have to ensure that there is no potential for transmission and some conditions need to be in play," he said. "These animals would be quarantined so there's no mixing and segregated from animals in Washington state to prevent [possible] transmission."

The flood threat is posing a risk to many first nations across the province.

Tribal council Grand Chief Clarence Pennier said numerous reserves are facing flood threats to varying degrees, among them the Matsqui in Mission-Abbotsford, Skway and Skwah near Chilliwack, Chehalis east of Mission, and Leq'a:mel at Deroche. Some federal reserves have benefitted from provincial funding for flood protection, including the Scowlitz at Harrison Mills as part of the District of Kent's dike improvements.

Pennier said there have been considerable efforts for more than one month now to ensure first nations in the lower Fraser are aware of the flood risk and equipped with emergency plans.

In Mount Currie, half of the 1,400 people on the Lil'wat First Nations reserve are at risk of flooding from the Birkenhead River. About 50 people living along the river were expected to be evacuated tonight, with the local gym set up as a reception centre for evacuees.

Band administrator Daniel Sailland said the dikes have stopped short of Mount Currie.

"The other half of the community could be affected but right now they're not in any peril," he said. "It's not an all-out state of emergency; it's something we're monitoring very closely and will evacuate families as needed."