Chehalis River (Washington)

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Chehalis River
Chehalis River Valley (left), Grays Harbor (middle distance) and Satsop River Valley (along bottom)
Country	United States
State	Washington
Counties	Grays Harbor, Thurston, Lewis
Major cities	Aberdeen, Centralia, Chehalis
Length	115 mi (185 km) ^[1]
Watershed	2,660 sq mi (6,889 km²) ^[2]
Discharge at	near Satsop, WA
- average	6,425 cu ft/s (182 m³/s) ^[3]
- maximum	47,000 cu ft/s (1,331 m³/s)
- minimum	440 cu ft/s (12 m³/s)
Discharge elsewhere
- mouth (Grays Harbor)	11,208 cu ft/s (317 m³/s) ^[2]
Source
- coordinates	46°27′6″N 123°17′30″W / 46.45167, -123.29167 ^[4]
- elevation	1,000 ft (305 m) ^[5]
Mouth	Pacific Ocean
- location	Grays Harbor, Aberdeen
- coordinates	46°57′29″N 123°50′5″W / 46.95806, -123.83472 ^[4]
- elevation	0 ft (0 m) ^[5]
Major tributaries
- right	South Fork Chehalis River, Newaukum River, Skookumchuck River, Satsop River, Wynoochee River, Wishkah River

For other places with the same name, see Chehalis River.

The Chehalis River is a river in Washington in the United States. It originates in several forks in southwestern Washington, flows east, then north, then west, in a large curve, before emptying into Grays Harbor, an estuary of the Pacific Ocean.

1 Course
- 1.1 December 3, 2007 floods
2 See also
3 References
4 External links

[edit] Course

The Chehalis River begins at the confluence of the West Fork Chehalis River and East Fork Chehalis River, in southwestern Lewis County. From there the Chehalis flows north and east, collecting tributary streams that drain the Willapa Hills and other low mountains of southwestern Washington. The South Fork Chehalis River joins the main river a few miles west of the city of Chehalis. The Newaukum River joins the Chehalis River at Chehalis, after which the river turns north, flowing by the city of Centralia, where the Skookumchuck River joins. After Centralia, the Chehalis River flows north and west, collecting tributaries such as the Black River, which drains the Black Hills to the north, the Satsop River and Wynoochee River, which drain the southern part of the Olympic Mountains.

The Wynoochee River joins the Chehalis near Montesano, after which the Chehalis River becomes increasingly affected by tides and widens into Grays Harbor estuary. The city of Aberdeen lies at the mouth of the Chehalis River. Just east of Aberdeen, the Wishkah River joins the Chehalis, and just west, between Aberdeen and Hoquiam, the Hoquiam River joins. At this point the river has become Grays Harbor. Before the estuary of Grays Harbor empties into the Pacific Ocean, the Humptulips River joins.

[edit] December 3, 2007 floods

During the December 2007 Pacific Northwest storms, a twenty-mile stretch of Interstate 5 was closed between exits 68 and 88 because of flooding from the Chehalis River, causing the roadway to be under about 10 feet (3.0 m) of water. The recommended detour added about four hours and 280 miles (450 km).^[6] It was not expected to reopen for several days.^[7] However, upon breaching a dike on Dec. 5, 2007,^[8] the water receded quicker than anticipated. Repairs to the roadway are scheduled to occur as soon as possible. Amtrak train service between Portland, Oregon and Vancouver, British Columbia was also disrupted.^[9] Washington governor Chris Gregoire declared a state of emergency on December 3.^[10]