Gale Creek Watershed in Washington County, Oregon
Prepared by:
Pamela Monnette
ES 492: GIS Applications in Earth Science
Hydrologic Summary
Introduction
General Geology
The watershed has 10 subbasins and contains 17 tributaries. Streams are fed primarily
by precipitation. Most streams in the low lying parts of the watershed have been
channelized and wetland areas have been drained for agriculture use.
This project demonstrates the many components of working with ArcView GIS
software. Compiled is a complete set of GIS vector map themes, Digital Elevation Models
(DEMS), Digital Raster Graphics (DRGs) and other GIS data for Gale Creek Watershed.
Watershed Location
Streams within Gale Creek Watershed Quadrangle Footprint
Gale Creek Watershed is located in the northwestern corner of Oregon and is
contained almost completely in Washington County. It is one of many large watersheds in
the Tualatin River Basin. It is situated on the eastern side of the Coast Range Mountains.
Legend
This figure was achieved
By clipping a larger stream network
to the area of the Quadrangles that
Gales Creek Watershed resides in.
Streams
N
W
Gale Creek Watershed
Oregon
The oldest geologic materials in the Gales Creek Watershed and volcanic and
sedimentary rocks formed during the Eocene and Oligocene ages of the Tertiary period.
The volcanic rocks and mostly basaltic lavas and tufts, overlain by sedimentary rocks
made up of shale, claystone, sandstone, and siltstone. There are 11 soil associations listed
in the Natural Resources Concervation Service (NRCS) Soil Survey of Washington County.
Soils in the Coast Range are well-drained silt loam and cobbly loam. The nearly level
flood plains consists of young alluvium, silt, and clay deposits approximately 20 to 30 feet
thick. The historic wetland areas have eight hydric soil types which are generally very
deep, poorly drained, and have slow surface runoff. The entire watershed is underlain by
sandstone 400 feet thick (Breuner).
Roads on bedrock
Task 9F
E
S
9
0
Legend
Streams on Vegetation
Task 9H
9
18 Miles
Highways
Bedrock Geology
1124
1150
1170
1173
2053
2070
2071
2075
2076
3994
7233
7240
7242
12435
12450
12532
12583
14660
Pamela Monnette
Task Two: Oregon Counties
Legend
The figure on the
right represents the
types of Timber in
Gales Creek
Watershed with the
streams in the area
overlain on top of
it.
Legend
Subb asins o f G ale Creek Watersh ed
Oregon Cou nties
Washington County
The watershed is entirely within
the Northwestern edge of
Washington County, except for 2
small portions extending into
Tillamook County.
Tillamook County
N
W
E
S
Streams
Tim ber Types
Merchantable Timber
Burned Areas re-stocking
Burned Areas non re-stock
Non-timber Areas
N
N
W
W
E
9000
0
9000
18000 Miles
S Pamela Monnette
S
7
0
7
14 Miles
Pamela Monnette
Physiography
9000
Roarin g Creek
87 - 194
195 - 301
302 - 409
410 - 516
517 - 624
625 - 731
732 - 839
840 - 946
947 - 1054
No Data
Woo ds Po in t
209 - 305
306 - 401
402 - 498
499 - 594
595 - 691
692 - 787
788 - 884
885 - 980
981 - 1077
No Data
Timber
122 - 209
210 - 297
298 - 384
385 - 472
473 - 559
560 - 647
648 - 734
735 - 822
823 - 910
No Data
Scholls
31 - 61
62 - 92
93 - 123
124 - 154
155 - 185
186 - 216
217 - 247
248 - 278
279 - 309
No Data
Laurel Wood
34 - 85
86 - 137
138 - 188
189 - 240
241 - 291
292 - 343
344 - 394
395 - 446
447 - 498
No Data
Gale C reek
47 - 102
103 - 158
159 - 214
215 - 270
271 - 326
327 - 382
383 - 438
439 - 494
495 - 550
No Data
Forest Grove
38 - 47
48 - 56
57 - 65
66 - 74
75 - 83
84 - 92
93 - 101
102 - 110
111 - 119
No Data
Cochran
264 - 355
356 - 446
447 - 537
538 - 628
629 - 719
720 - 810
811 - 901
902 - 992
993 - 1083
No Data
Buxton
56 - 125
126 - 194
195 - 263
264 - 332
333 - 401
402 - 470
471 - 539
540 - 608
609 - 677
No Data
DEMs
E
S
W
10000
0
Timber
10000
Buxton
20000
Miles
E
The climate with the watershed is marine-influence with an extended winter
rainy season. Summers tend to be hot and dry with little rainfall. The Coast Range
Mountains form the upper north and Western boundaries of the watershed, separating
it from the Pacific Ocean to the west. The mountain slopes tend to be steep with high
gradient streams.
S
DOQs
Cochran
Gales Creek Pictures
Climate
N
Quad DRGs for Gale Creek Wateshed
18000 Miles
The watershed contains a mosaic of native and exotic plant species. The
original forested uplands, most of which was logged 40 to 80 years ago or burned in
two stand-replacing fires in 1933 and 1945, known as the Tillamook Burn, have been
replaced with Douglas-fir forests which are intensively managed. Furthermore, black
cottonwood, bigleaf maple, Oregon ash, vine maple and elderberry are the dominant
plant species in the riparian zone of Gales Creek (Breuner).
Digital Orthophoto Quads
for Gale Creek Watershed
W
9000
Timber and Vegetation
On the left is a Digital Elevation Model
of all of the Quads that make up
Gales Creek Watershed. The darker
areas represent higher elevations,
while the lighter areas represent lower
elevations.
Digital Orthophotos
of Gales Creek
Watershed
Quadrangels
0
Above is a figure showing the distribution of bedrock
Geology within Gales Creek Watershed. The colors
Are represented by codes that correspond to different
Types of rock. Overlain onto this theme, is a map of
Major highways.
Pamela Monnette
The watershed ranges in elevation from a low of 159 ft. above sea level, at the
confluence with the Tualatin River, to its highest point of 3,154 ft. The mainstem of Gales
Creek is 23.5 miles long and flows in a southeasterly direction. Land designations promote
the rural character of the watershed by limiting land uses to forestry, agriculture,
scatteredQuad
ruralDigital
residences,
rural
services. Almost two-thirds of the watershed is
Elevationand
Model
in feet
privately owned (Breuner).
N
80-90
100-120
60-70
56-60
Pamela Monette
Legend
Gale C re ek W atershed b ou nda ry
50000
0
50000
This is a figure displaying the
precipitation in inches annually
received in Gales Creek Watershed.
60-70
100000 Miles
Pamela Monnette
48-52
and DRGs!
Forest Grove
Woods Point
Roaring Creek
0
Gales Creek
10000
N
Here we see an image of
digital raster
graphics
W
E with
an outline of the Gales Creek
Watershed boundary
overlain
S
on top of the quads.
Laurel Wood
10000
Hillsboro
E
Conclusions
This project focused on finding and displaying various GIS data for Gales Creek
Watershed. It included assembling DRG, DEM, DOQ, bedrock geology, precipitation,
soils, vegetation (timber), streams and road themes in the form of our particular
watershed.
44-48
References Cited
40-44
Breuner, Nancy. (1998). Gales Creek Watershed Assessment Project. Tualatin River
Watershed Council.
Scholls
20000 Miles
Pamela Monnette