The town of Oliver in the Okanagan, a rural area of British Columbia, Canada, was hit by a mud and debris flow yesterday, June 13. This flow originated in an incised canyon where Testalinda Creek flowed from a lake. Five homes were swept off their foundation, there were no injuries.
As pointed out on Dave's Landslide Blog (on June 14), Oliver sits on a small debris fan, shown as the triangular area just above the highway 97 sign in this photo from Google Earth (click on the photo to enlarge it so that you can actually see the debris fan). Upstream from Oliver is a lake, drained by Testalinda Creek which flows in a deeply incised canyon. In such situations, debris can build up at the bottleneck in the canyon to effectively form a dam. When rain has saturated the soil, as has been the case this rainy summer, the debris pile can let loose and send a torrent of water, mud, and debris out into the surrounding country side.
No comments:
Post a Comment