Flooding in Oregon, December 27 to 30, 1998

A Pacific storm on December 27-28 dumped 2 to 5 inches of rain in lowlands and 6 to 10 inches of rain in the Coast Range. This deluge, on top of heavy rain December 25-26, combined with saturated soils and a rapidly melted heavy low elevation snowpack and frozen subsurface soils from the pre-Holiday arctic outbreak to create widespread lowland flooding. The Wilson River near Tillamook crested at 19.6 feet, which was higher than the previous record high flood of 19.51 feet in February 1996. The Tillamook area had 4 inches of rain December 27-28, and nearby mountains had the 6 to 10 inch totals, so the Tillamook area was the hardest hit. Fortunately, rain ended December 28, and rivers rapidly receded to below flood stage by the 30th. The rapid rise and fall of the Wilson river was almost like a flash flood. Many highways throughout Northwest Oregon were closed due to slides and washouts, especially along the coast and Coast Range. Highway 101 along the coast was closed for several days, and the Oregon Highway department estimated $1.5 million damages to roads and highways. A slide destroyed a house near Alsea, and closed the highway to Corvallis. At least 30 other houses were destroyed. Fortunately, no deaths or serious injuries were reported during this episode. The Siletz river area and the community of Scio were was also especially hard hit by flooding. Total damages will likely be in the $2-4 million range.