|The following timeline encompasses the Puyallup, Carbon, White and Nisqually rivers, with groundwater, coastal and urban flooding.
Prior to confinement and implementation of river training techniques, the lower Puyallup River was free to migrate throughout the valley migration was a natural response due to the high sediment and debris load.
Pierce County created by Oregon Territorial Legislature.
Beginning of flood protection work in the Puyallup River Basin with the arrival of settlers. Early history entails settlers trying to stabilize the river channel.
Prior to 1906
The White River flowed north into King County and into the Duwamish River. The Stuck River ran parallel to the White River separated by a few hundred feet near what is now Auburn Game Farm. During high flows or debris jams, the White River would overflow its banks and divert to the Stuck River. There are unconfirmed stories that King County residents attempted to permanently divert the White River south to the Puyallup River through the use of dynamite and other methods.
Nov. 15, 1906
A disastrous flood event in November 1906 caused the river to be blocked by a massive log jam. This caused a channel avulsion and diverted the White River to flow south into the Stuck River, which leads to the Puyallup River. This caused devastating flooding in Puyallup and Tacoma.
The United States Army Corps of Engineers investigated and made recommendations in the Duwamish-Puyallup Flood Problem. The report recommended the 1) the diversion of the White remain, and 2) a joint flood control effort be established between King and Pierce counties. At that time there was no legal mechanism for this type of joint work to occur. Washington State Legislature gave county governments the authority to tax for the purposed to fund flood-protection work on rivers.
Washington State passed RCW 86.13 which permitted interlocal agreements between counties to jointly fund and perform flood control works that affected both counties
Pierce and King counties formed the Inter County River Improvement District (ICRI). The ICRI Agreement covered a 19 mile stretch of the White and Puyallup rivers from the City of Tacoma to the Muckleshoot Indian Reservation. This is Pierce County’s first flood plan.
Preliminary flood control efforts of ICRI focused on the lower 10 miles of the Puyallup River and the lower 8 miles of the White River. Projects focused on straightening river channels, debris removal, construction of hydraulic structures, and dredging. The life expectancy on these revetments was consequently approximately 10 years and many of them had to be periodically replaced.
At the same time, the Pierce County River Improvement began flood control work on the middle and upper Puyallup River. Work focused on debris removal, and construction of hydraulic structures. The primary focus of this work was to preserve farm land and to allow the river to fill in behind the silt fences to create additional farm land.
Ongoing levee/revetment construction.
1930s & 1940s
Pierce County River Improvement continued to construct low levees and revetments to prevent channel migration through agricultural lands along the in the middle and upper Puyallup River.
1930s and 1940s
Works Projects Administration (WPA) involved with channel clearing/dike repair/new dikes.
Dec. 10, 1933
Major flood throughout the watershed (White River watershed =100-year flood event 1) Puyallup gauged at 57,000 cfs.
U.S. Flood Control Act authorized U.S. Army Corps of Engineers to construct the Mud Mountain Dam on the White River (29.6 RM) 5 miles east of Buckley for flood control in the lower Puyallup River.
June 5, 1939
Pierce County approved a plan (Resolution No. 686) for flood control for the upper Puyallup and Carbon rivers (above the mouth of the White River).
River Improvement policies changed. The river channel was straightened and confined with levees and revetments. The new levee/revetment systems were designed to prevent sediment sources on riverine walls from entering the channel and to increase sediment transport by narrowing the channel to 300 feet in width.
Maximum amount of rivers are now channelized. Forty five river miles channelized, including 14.7 miles of concrete armored dikes and 57.3 miles of dikes and riprap riverbank armor.
Dec. 2, 1977
Mild flooding throughout the watershed (Upper White River = 50-year flood event).
Primarily maintenance/operations occurred during this time.
ICRI-PCRI agreement with the Puyallup Tribe of Indians for all their vegetation removal and trimming.
Jan. 9, 1990
Flooding throughout the watershed (Lower Puyallup = 50-year flood event).
Nov. 24. 1990
Flooding on the Carbon (100-year flood event) and Upper White rivers.
Adoption of the Comprehensive Flood Plan for the Puyallup Watershed; new preferred alternatives.
|Rain on snow event. The ground froze and was unable to absorb rainwater.
Urban Groundwater flooding.
|Major flood event countywide (100-year flood event).
Significant River event.
Pierce County Council forms the Pierce County Flood Control Zone District. It is a countywide district to pay for flood improvements within Pierce County.
|Coastal flooding in Dash Point.
|Dec. 17, 2012
|King Tide event in Purdy.
High tide flood in Dash Point on Whitman Drive.
Pierce County adopts Rivers Flood Hazard Management Plan. Plan expanded to include the Nisqually River and rivers and streams with a peak flow of 5,000 cubic feet per second (cfs).
Pierce County adopts Flood Control Zone District Comprehensive Plan of Development.
|Winds cause coastal flooding in Purdy.
Spring groundwater event.
Pierce County adopts updated Rivers Flood Hazard Management Plan.