Water levels on B.C.'s upper Fraser River have peaked, putting several Fraser Valley communities under evacuation alerts as the water rushes south.

The Fraser River peaked early Wednesday morning in Prince George at 10.02 metres, just below flood levels of 40 years ago, but the threat of flooding remains.

In the Fraser Valley, the swollen river forced the closure of the Edgewater Bar campground in Derby Reach Regional Park.

Campground host Duane Tucker said the river reached about this level last year, but that was the absolute peak.

"It's about up to its highest level now," he told CBC News Wednesday morning.

"It has receded a little bit this morning from what it was yesterday and the day before, but the prediction is that it's going to rise substantially in the next two to three days, possibly as much as six feet."

Tucker said the campground will stay closed until the water recedes, which could take at least a week.

The B.C. River Forecast Centre says warm, wet weather means the lower Fraser will keep rising. It is expected to peak late Friday.

'Hoping it will hold'

Meanwhile, officials in Abbotsford issued an evacuation alert for people living in unprotected areas of Glen Valley, as well as a small number of homeowners living between the dike system and the Fraser River.

Langley Township residents living along the banks of the Fraser River were put on an evacuation alert Wednesday afternoon. Officials say the alert was triggered when river levels reached about 5.5 metres in Mission.

In Chilliwack, about 200 properties — including 43 homes — are under evacuation alert.

Chilliwack area farmer John van den Brink said local farmers have their fingers crossed that a berm they helped build with some of their own money to hold back the Fraser holds this year.

The berm protects about 150 hectares of farmland that includes van den Brink's hazelnut farm, vineyards and blueberry farms, he said.

"We rebuilt the berm this year to protect the land behind the dike," said van den Brink, adding he and others paid $7,000 each after $50,000 in contributions from the province and local government.

"We're hoping it will hold," he said. "But if [the water] comes up [another] full metre, which they were talking about earlier, then it becomes another question."

No relief in sight

Justice Minister Shirley Bond said Tuesday melting snowpacks and heavy rains have much of the province on flood watch, including the Okanagan and Fraser Valley areas.

She urged British Columbians to heed local evacuation notices, saying local residents must rely on the experts when it comes to floods and leave their homes when asked.

"The key factor we're challenged with is weather," said Bond in what is expected to be regular flood watch briefings by Emergency Management BC and the River Forecast Centre.

"We are seeing large volumes of water in specific areas of the province. We're not looking at much relief in terms of the weather forecasts."

Bond said some of the preparations underway include installing three kilometres of portable, sand-filled dikes in a low-lying neighbourhood in Prince George and installing eight kilometres of similar portable dikes in agricultural areas near Chilliwack.

"We have about 1,000 wildfire firefighters who are specially trained and have rolled up their sleeves and are certainly available to lend a hand with sandbagging in communities," she said.

Bond said the province has a stockpile of two million sandbags, of which 700,000 are already in use.

More rain in forecast

River forecast centre spokesperson David Campbell said the current Fraser River surge was expected to reach the Fraser Valley at Mission, where the river level is measured, by Friday.

He said much of the Fraser Valley area has a dike system to withstand river levels of 8.89 metres, and the current forecast has the water level projected to reach 6.38 metres at Mission.

Campbell said warm weather followed by rains could see increased water flows in the Fraser Valley this weekend as area streams that flow into the Fraser experience increased levels.

He said depending on how much rain falls over the next few days, the potential for more high water on the Fraser remains.

Chris Bone, spokeswoman for Prince George's emergency management, said about 20 people living in eight homes near a neighbourhood that is traditionally threatened by the Fraser River every spring have heeded this week's evacuation notice issued to 17 homes.

Bone said the river water is currently touching some of the homes, but local officials were breathing a momentary sigh of relief as the flood threat from the Fraser River appeared to ease slightly.

But Prince George could still face flood threats because warm weather followed by rain on the weekend is in the weather forecast, said Bone, which means at least two more weeks of potential high water.

Other warnings and advisories

The B.C. River Forecast Centre flood warnings remained in effect for the Fraser River at Prince George and upstream, and downstream from Quesnel to the Fraser Canyon. A high streamflow advisory remains in place for the lower Fraser River.

On Tuesday afternoon, the forecast centre also issued a flood advisory for the North and South Thompson rivers, warning that water levels on both rivers will likely rise at least 60 centimetres over the next few days.

It also warned that as of Wednesday all boat launches would be closed, and the City of Kamloops is asking boaters to stay off the water.

The North Okanagan Regional District also issued a evacuation alert for low-lying properties along the Shuswap River from Sugar Lake to Mara Lake on Tuesday, warning residents to be ready to leave at a moment's notice should water levels continue to rise.

Advisory guidelines: A high streamflow advisory means that river levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible.

A flood watch means that river levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.

A flood warning means that river levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to the rivers affected will result.

Other flood watches, warnings and advisories include:

Shuswap River downstream of Mabel Lake (near Enderby) — flood warning.

Shuswap River upstream of Mabel Lake (near Lumby) — flood watch.

North Thompson River and tributaries — flood advisory.

South Thompson River and Shuswap Lake — flood advisory.

Quesnel River — flood watch.

Nechako River near Prince George — high streamflow advisory.

North Thompson River and tributaries — high streamflow advisory (downgraded).

Cariboo region (including the Horsefly River) — high streamflow advisory (downgraded).

Skeena and tributaries (including Bulkley River) — ended.

Upper Columbia River and tributaries — ended.

Seymour River and Eagle River (Shuswap tributaries) — ended.

Okanagan (including North Okanagan and Mission Creek) — ended.

DriveBC is reporting river ferries at Big Bar, Little Fort, Lytton, McLure and Usk have all been closed because of high water.