Oliver, B.C. -- An unusual calamity swept down on stunned vintners in British Columbia’s southern Okanagan Valley Sunday, when an irrigation reservoir swollen with days’ worth of rain burst its bounds and transformed Testalinden Creek into a mud-laden torrent.The slide occurred at about 2:20 p.m. local time on one of the first sunny days the area had seen this spring. Flabbergasted residents watched as the torrent swept away homes and sheds, depositing five to six feet of silt on orchards and vineyards.