Downstream Assistance Program for the Snoqualmie Flood Reduction Project
(also known as Snoqualmie 205 Project)

The Snoqualmie 205 Project is expected to reduce flood depths in the Snoqualmie area by more than one foot, and to prevent $837,000 in average annual flood damages. However, by helping to move flood waters out of Snoqualmie, the project is expected to cause a small increase to the depth of flooding downstream. The U.S. Army Corps of Engineers estimates that 100-year flood levels could be roughly 0.1 ft. higher along the Snoqualmie River from Fall City to Carnation. Smaller, more frequent floods would have smaller changes (meaning the increased depth would be less than 0.1 ft.). These federal estimates have been verified by an independent consultant review. Following are links to additional details.

Fact Sheet provided by the U.S. Army Corps of Engineers.

Slide Show provided by the U.S. Army Corps of Engineers.
(Adobe Acrobat Viewer required, file size 2,106KB )

Letter Report (independent review) from Northwest Hydraulic Consultants, Inc.
(Adobe Acrobat Viewer required, file size 454KB)

These materials were presented to the downstream community in a series of public meetings held in Fall City and Carnation. Participants described the severity of the existing flood problem in the lower Snoqualmie Valley, and expressed concern about even a small increase to their flood problems. Participants also helped to suggest and to rank various methods that could be used to mitigate this increase. From that input, the Downstream Assistance Program (DAP) was developed.

The DAP would provide a cost share to help landowners reduce their risk of flood damage by raising their flood-prone homes or other structures (including barns). Landowner participation is voluntary. Those landowners who choose to participate would hire contractors to raise existing homes or other structures to a higher level. The DAP would reimburse a portion of the related expenses.

The DAP will use a variable cost share percentage that will depend upon decisions made by the landowners involved. If a large number of landowners complete these construction projects, the DAP will provide a relatively small cost share percentage. Conversely, if a small number of landowners complete construction, the DAP may provide a much greater percentage of their costs. Given this relationship, the final cost share percentages will not be known until after all DAP construction is complete.

The overall DAP budget has been negotiated and established in agreements between King County, the City of Snoqualmie, and the U.S. Army Corps of Engineers. This budget was based on the relatively small fraction of the downstream flood problem that could be attributable to the Snoqualmie 205 Project. DAP cost shares are as follows:

The bulk of this DAP budget will be distributed in landowner reimbursements at a uniform percentage rate across all eligible expenses incurred by those who participate. Because the reimbursement rate will be uniform throughout the DAP, each landowner’s decisions will affect all other DAP participants as well. Therefore, the program will have firm deadlines for several landowner tasks. These deadlines must be firm in order for the program to determine overall expenses and, more important, to provide other participants with reliable information they can use when making their own project decisions. (Note: deadlines will be firm, but most of those deadlines have not been set.)

Following is the projected schedule for the DAP.

Projected Schedule

Additional procedural details are described in draft agreement language, which is much like that used by King County in several previous grant-funded residential elevation projects.

Please direct any comments or questions to River and Floodplain Management Unit Section Senior Engineer Tom Bean, 206-296-8377.