Alsea Basin Watershed – Lincoln County, Oregon
Prepared by:
Seth Webb & Andrew Holmes
ES 341
INTRODUCTION
The Alsea Basin Watershed consists of both private timber land and public land
via the Siuslaw National Forest. The land promotes the rural character of the
watershed by limiting land uses to its vast forestry, scattered rural residences, and
rural services.
Hydrologic Summary
The Alsea Basin Watershed covers about 128 square km. Beaver Creek runs
through the middle of the watershed and many other creeks run off of it. There are
a total of 6 subbasins in the watersheds, each feeds into the Pacific Ocean.
Physiography
The Alsea Basin Watershed ranges from 0 feet to about 2020 feet, running from
the coastal floor up to the Coastal Mountain range (See figure 7). The terrain is an
increasing slope from the coast to the east that consists of your typical western
Oregon vegetation (See figure 8).
Watershed Location
The Alsea Basin Watershed is located on the western part of the state in Lincoln
County. The watershed is on the Oregon coast as well.
Figure 7 – Elevation
Figure 8 – Typical Vegetation
Figure 1 – Map of Oregon
with watershed location
Figure 5 – Streams within the watershed
Figure 2 – Watershed Counties
General Geology
The Alsea Basin offers a variety of geologic formations and soil formations. Many
marine rocks and sands can be found near the coast, while a large Tyee formation
can be found near the coast range. A large variety of soil types can be found
throughout the basin.
Figure 3 – Different Soil Types
Figure 4 – Geologic Bedrock
Figure 9 – Aerial Photos
Figure 6 – Subbasins within the watershed
Figure 11 – Annual Precipitation
Figure 10 - Topography