Could 2018 be a year of catastrophic flooding in the Lower Fraser River valley?
It’s too soon to say, but some early signs are not encouraging.
There is a heavy snowpack in much of the drainage basin, which covers much of the southern half of the province. Snow kept falling in March and early-April, and only a small amount melted last month.
Then temperatures soared.
Reports of flooding started coming about three weeks ago. There has been significant flooding in Cache Creek and Merritt, as well as in Osoyoos, Keremeos and Grand Forks.
The latter has been the hardest-hit thus far, with flood levels there matching 1948 – the year of the disastrous Fraser River flood.
On a trip to the Interior in late-February, we were surprised at the depth of snow in the valley bottoms. On the mountain slopes, the depth was wonderful for skiing, but it was also a troubling sign of potential problems this spring.
The snow continued to fall in higher areas for another six or seven weeks, as drivers on the Coquihalla Highway or Okanagan Connector can attest.
Higher temperatures, particularly if they last for weeks, will cause the snow at higher elevations to melt quickly. River levels are already quite high.
It was announced last Wednesday that Barnston Island is on flood alert, with access restricted. That island, off Port Kells, was submerged in the 1948 flood.
The 1948 flood began in similar ways. It was a cool spring, and there had been lots of snow over the winter. In late May, temperatures rose quickly.
Fraser Valley flooding began when dykes burst at Agassiz, late on May 24 – the holiday Monday. By the week’s end, dykes had burst in Chilliwack, Mission, Matsqui and Langley.
In Surrey and Delta, flooding was less severe. Other than Barnston Island, the main areas affected were Port Mann and South Westminster. Some people had to leave their homes, and the CN operations were restricted. In some ways, that didn’t matter, as rail communication with the rest of Canada had been cut off by flooding further up the valley.
At that time, rail was the main means of travel. The Lower Mainland was effectively cut off from the rest of Canada.
Now, if ever there is flooding on such a scale in the Fraser river basin, the damages would be in the billions. The entire area from Hope to Richmond has built up dramatically, and a great deal of development is on low-lying lands.
This year, the Fraser River in the valley had been rising slowly, but it has come up quickly in recent days. However, the river is still far from the flood stage. The chances of flooding are still quite low.
The weather may cool down, the dykes are better than in 1948 and newer homes have had to meet stricter requirements to avoid flood damage.
Nonetheless, it is important to remember flooding on a major scale took place in 1948 and, on an even larger scale, in 1894. It can happen again.
Frank Bucholtz writes Wednesdays for Peace Arch News.
