The annual mean yearly runoff in western Washington during the 1981 water year ranged generally from 90 to 100 percent of normal, except for the Olympic Peninsula, which was about 110 percent of normal. Precipitation was deficient throughout the area during October and January, and was excessive during November and June. Precipitation was near monthly averages for other months of the water year.

Floods were experienced at many streams in the northern Cascade Range in December. The heaviest flow (approximately 100-year recurrence interval) occurred December 26 on the Sauk River. Chehalis River, a lowland stream in the southern portion of the region, had below normal runoff during October, November, January, and March, with normal or above flows for the remaining months, and annual runoff was 95 percent of normal. Skykomish River, a mountainous stream of the northern Cascade Mountain Range, had an annual runoff that was 102 percent of normal, and monthly flows were below normal except for November, December (192 percent of normal), February, and April.

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