The city of Chehalis is located in Washington state and rests upon the Chehalis River. With a connection of creeks, minor tributaries, and basins within or near the city, coupled with the nearby confluences of the Newaukum River south of Chehalis and the Skookumchuck River in neighboring Centralia, the community has suffered from numerous floods. Due to the city being located in the Chehalis Valley along with the Cowlitz River, cresting and overflow of the river has led to flooding in the Chehalis area.
Water inundation from heavy rains and excessive snowmelt has led to a considerable number of historic flooding events in the area, with accounts traced as far back as early Native American settlement and since the beginnings of the city of Chehalis.
Native American flood history
Historical accounts and spiritual lessons passed down through the history of Native American people living in and around the Chehalis River tell of major floods in the basin. Chronicles of the Cowlitz Indian Tribe speak of floods that reached the pinnacle of Mt. St. Helens leading to the beginnings of the tribe. The Chehalis people have traditional stories of floods that led to the transformation of humans and animals and how they interacted between one another and their habitat.
Flood events in the 19th century
Chehalis was founded in 1873 and officially incorporated in 1883. The first newspaper in the town would begin operations that same year.
In the 19th century, two significant floods were recorded in the local newspapers. A flood in December 1887 was stated to have been due in part to heavy rains after a dry summer. Two Chehalis residents died and some local areas were underwater by as much as six feet. River traffic, sawmill operations, and railroads were delayed. Two back-to-back minor floods occurred in December 1897, severely damaging a railroad bridge in nearby Claquato.
Flood events in the 20th century
The 20th century recorded over two dozen notable flooding events in and around the Chehalis community. An episode of rising waters in 1906 on the Cowlitz River would affect the area and a larger event of excess rise to the Chehalis and Newaukum rivers in November 1909 would inundate the Southwest Washington Fairgrounds and cause significant economic losses to lumber milling in the city. A few months later in 1910, another flood event caused minimal damage.
In December 1915, the city was hit by a flood from a storm reported as the "Worst in City’s History". The Chehalis and Skookumchuck rivers overflowed and additional rain a few days later caused the banks of the Cowlitz River to be overwhelmed. Damages were reported as limited, but several roads and bridges were washed out and sawmills shut down their operations. Four years later, in January 1919, a deluge was declared as, "Present Flood Probably Worst in City’s History". The three major rivers in the area overflowed and landslides would disconnect travel and communities in the area. The flood was reported to have broken the record for highest depth. A smaller inundation would be recorded in December 1921 that would come within two feet of the record.
Chehalis was submerged in a month-long rain event, totaling over 22 inches, in December 1933. The heavy rains affected most of Western Washington including roads between Portland and Tacoma. Passage between the Twin Cities was closed, and railroad traffic and postal services were disrupted in Chehalis. The city's Alexander Park would be submerged. Flood records were broken and damages were estimated to be as high as $50,000 in the county. Heavy rainfall events in 1936 and 1937 led to additional, moderate flooding, and a 1939 flood submerged the Chehalis–Centralia Airport. A Cowlitz River overflow in 1946 would affect the city.
The Chehalis and Newaukum crested in 1948 after heavy rainfall and would lead to the closure of the airport. The 1948 weather pattern that led to the flood was a widespread disaster for the state. A 1949 rainfall event affected the city as the Cowlitz overflowed. Heavy rains in 1951 and 1953 led to moderate, local flooding. A December 1955 inundation occurred due to a quick rise in the water of the Chehalis River. A wind event, described as a "twister", would hit the area days after. A minor flood would be reported in 1959.