Pierce County has made this project inactive because the benefits did not outweigh the costs. In 2018, the project team wrapped up the draft technical reports, permit applications and cost-benefit analysis. Unfortunately, the cost efficiencies and benefits were not high enough for funding. Some of the restoration and flood-reduction methods from this project were found effective, and Pierce County may incorporate these methods into future projects.
This project caused the development of new techniques to improve instream conditions resulting in benefits to habitat and flooding. The team will prepare a summary report for other jurisdictions to inform their flood reduction projects. This report will be made publicly available mid-2019.
This project takes the recommendation from the county flood plan and incorporated habitat creation in the project area. The criteria for project site selection included areas with little-to-no habitat due to restricted movement of the Puyallup River. An overview of the site-selection process and the overall project is available in addition to a shorter fact sheet about the project.
About the Project
Mount Rainier provides the Puyallup, White and Carbon rivers with an extraordinary and constant supply of sediment. This sediment contributes to frequent flooding that often threatens public safety, property and infrastructure. Pierce County is exploring whether targeted sediment removal could be an appropriate tool to reduce flood risk in specific circumstances and improve habitat.
Pierce County employs many tools and strategies to reduce flood risk. These tools include levees, side channels and log jams that slow and divert rivers away from critical areas. The county is exploring additional opportunities to reduce flood risk in areas where it may be difficult to implement other flood hazard reduction strategies and where flooding is most likely to damage public resources in the foreseeable future. Gravel removal may provide an additional tool to help lessen damage from moderate flooding events. In addition, this project is being designed to improve habitat for many fish species that use the river.
The county is committed to flood risk reduction strategies that reduce flood damage and benefit the environment. This project is fact-finding in nature, and its results will determine if targeted sediment removal could be an appropriate and cost-effective strategy to reduce flood risk. The project is only to evaluate potential applications of sediment removal and related habitat benefits. The evaluation process will include a thorough environmental review and public input opportunities.
Is sediment removal an effective method for localized flood hazard risk reduction during moderate flood events in the Puyallup River basin, and can a sediment removal project be designed to measurably improve habitat and reduce flood risk at the same time?
Pierce County staff is available to provide presentations about the development of the project at local city council meetings and community meetings upon request. To request a presentation, please contact Angela Angove.
Project Funding Source: Surface Water Management Utility
Winter - Summer 2017:
More technical analysis of the preferred project location and sediment removal methods.
Conceptual design, including monitoring and adaptive management plan.
Technical studies and environmental documentation.
Continue outreach to agencies, stakeholders and interested parties.