Nightmare on the Fraser

A wet, snowy winter combines with an early hot spring to flood the Fraser River. Dikes from Chilliwack west are overwhelmed. Tens of thousands are evacuated. Billions of dollars are lost. It was the nightmare scenario Chris Wood envisioned in a Tyee investigative series last summer. But new warnings from B.C.'s Environment Ministry have some saying the nightmare could be just months away.

Snow packs in some parts of the province are 160 per cent of normal, according to a story in yesterday's Globe and Mail. That, combined with what is expected to be one of the hottest springs on record, has the province's river forecast centre saying the flood risk on the Fraser is at its highest in a decade.

Yesterday, we checked in with Wood to get his thoughts on the new developments. He wasn't optimistic.

"With the right combination of rain and snow and timing...throw in a high spring tide at the wrong moment (which I left out of my scenario) and sure it could be bad," Wood said in an e-mail. "Could it be as bad [as the situation in my story]? Truly."

Wood said three factors, all related to climate change, are converging to create a high-risk situation. "One is that we're getting more wild swings of weather, so we could go from a whole lot of snow to a very warm spell very quickly," Wood said. "Another is that we're more frequently getting heavy rain (rather than additional snow) in late winter or spring. That both helps the snow melt faster and adds its own load of water to the runoff.

"Finally, spring is coming earlier by several weeks compared to the middle of the last century. So it can all happen sooner that you'd think."

Despite the increased risk, no work has yet been done to dredge the gravel and silt pushing up the river floor. (A rising river floor means a rising river, which means old dikes can grow obsolete fast.) Last week, Environment Minister Barry Penner said "there has been some discussion at fairly high levels," about getting dredging, but "things did hit a snag."

For Wood, the time for delays is over. "This is exactly why we need to be preparing for consequences now rather that putting it off in the false security of thinking that the effects of climate change are somewhere out there at the end of the century," Wood said. "It takes time to raise dikes, or to dredge at a time of year that won't harm fish. You don't want to be trying to do it as the flood crest is hitting Yale."