For the past several weeks there has been increasing awareness of the above average snowpack in the catchment area of the Fraser River. In mid May snowpacks in the Upper Fraser were up to 75% above average for the time of year and still accumulating snow, while in the Lower Fraser they were up to 30% above normal. This provides one of the components necessary for an extreme flood in the highly populated Lower Fraser Valley. The other main factor is the temperature. Rainfall has a relatively minor influence. Furthermore, a recent study has shown that the Lower Fraser dykes are too low by as much as 1 m in some locations.
In response to this threat, the Provincial Government has recently spent $33M on 87 flood protection projects in BC. The Federal Government has also released funds to assist First Nations prepare for the potential flood. Hay & Company has been involved in several of these projects. Helen Soderholm P.Eng. has been managing construction of a dyke on McMillan Island for the Kwantlen First Nation and providing advice to the Kwikwetlem First Nation. Bob Wallwork, P.Eng. has been assisting the Katzie, Musqueam, Scowlitz, Soowahlie, and Leq’a:mel First Nations. Adrian Chantler, P.Eng. has been advising the Seabird Island and Peters First Nations, assisted by Albert Leung, EIT who spent time on the Seabird Island reserve supervising construction of a temporary lock-block wall and some emergency bank protection. Hayco and EBA engineers are also currently working on another flood protection project, which is under construction for the Chehalis Indian Band.
At the time of writing snowmelt has proceeded in a ‘controlled’ manner resulting in flows at Hope around the upper quartile rate. However, a high pressure ridge is forecast to produce temperatures well above normal for the interior mountains for the next five days, so whether or not these flood defences will be needed remains a subject for speculation.This page was last updated on: 5/31/2007 9:11:42 AM