Kilchis River Watershed Tillamook, Oregon
Prepared by:
Joseph Krom
Thomas VanNice
Bedrock Geology
Oregon Map
GENERAL GEOLOGY
INTRODUCTION
DRG Quads
DEM Elevation
The Kilchis River Watershed is located just north of Tillamook, Oregon and only in
Tillamook County. Most of the roads that run through the watershed are gravel
and dirt, but there is one highway that crosses through the watershed at the base.
The water shed is made up of 13 smaller basins. The total area of the Kilchis
River Watershed is 168 sq. km. The length to width ratio is 1 to 1.97.
Annual Precipitation
The Kilchis River watershed contains 4 different surficial geologic units (bedrock
types). The 4 surficial geologic units within this watershed are Qal (river alluvium
deposits of Holocene age), Tsd (sedimentary rocks of Oligocene to upper Eocene
age), Ttv (Tillamook volcanic rocks of Eocene age), and Ttvm (marine facies
which consists of clastic rocks and pillow lavas). There are 44 different soil types
within the Kilchis River watershed, and the composition of these soils ranges from
silty loam to conglomerate.
Canopy Vegetation
PHYSIOGRAPHY
Rivers
The height elevation of the Kilchis River Watershed is 1006 meters and it runs all
the way to the ocean. Since the basin runs into the ocean, some of the slope is
equal to zero. The maximum slope is 60.2 degrees. The average slope in degrees
is 29.1. The average precipitation for the Kilchis River Watershed is 115 inches
per year. In some areas, the precipitation is over 180 inches per year. The canopy
vegetation consists of three main types of cover. The main type consists of,
Douglas Fir and Western Hemlock and Grand Fir forest. The next most popular
consists of both, Sitka Spruce and Western Hemlock forest. The last is made up
of mixed conifer and broadleaf deciduous forest.
HYDROLOGIC SUMMARY
Soils
The Kilchis River watershed contains 13 total Sub-basins, and the average area of
each Sub-basin is 12,934,920.5 square meters. In addition, the Kilchis River
watershed is 23 kilometers long and 11.7 kilometers wide. Its total drainage area
is 168 square kilometers, it contains a total of 1,717 stream segments.