chehalis basin
left|400px|Chehalis planning sub-basins as defined by the Chehalis Lead Entity The Chehalis Basin is the largest basin entirely in the State of Washington. The basin is divided into upper and lower Water Resource Inventory Areas. The more contemporary Office of the Chehalis Basin divides the basin into three areas. The Upper Chehalis is centered on the twin cities of Chehalis and Centralia. These towns were established in the broad valley where the Chehalis Headwaters, Newaukum and Skookumchuck Rivers join, collecting water from the East Willapa Hills and South Cascade foothills. Shortly downstream, this flow is joined by water from the Outwash Plains including Scatter Creek and the Black River. After passing the Black Hills, the Lower Chehalis Basin receives flows from a series of Rivers flowing from the South Olympic Mountains into the oversized Lower Chehalis Floodplain, including the Satsop River, Whynoochee River, Wishkah River, finally emptyig into Grays Harbor at the cities of Aberdeen and Hoquiam. The Estuary further collects the Humptullips River, Johns River and Elk River, and the mouth is frames by two massive sand spits, Ocean Shores and Westport. To the north of this region is the Olympic Coast, and to the south is Willapa Bay
Relationships
- related to: Assisted Migration of Vegetation
- related to: Conifer Canopy
- related to: cutthroat trout
- related to: flora
- related to: integrated floodplain management
- related to: woods creek watershed
- related to: Bioregions
- related to: Skookumchuck River Watershed
- related to: black river
- related to: scatter creek
- related to: washington coast
- related to: whidbey basin
- related to: Chehalis Freshwater Mussel Working Group
- related to: Chehalis River Basin Land Trust
- related to: Aquatic Species Restoration Program (Chehalis)