River Flooding

What is River Flooding?

This type of flooding creates the most problems for Pierce County residents and businesses. In the 1990s, five floods were bad enough to have presidential declarations. Two more presidential declarations were made in the 2000s. River flooding occurs when a storm with a lot of water parks itself at Mt. Rainier and lets loose over several days. That water causes the rivers to rise quickly – going over their banks, eroding levees, and backwatering into creeks that drain into the rivers which causes the creeks to overflow. While these floods can be destructive, Pierce County usually has a few days’ notice they are coming. Knowing the flooding is coming gives people time to prepare.

Did You Know?

Building more levees and dredging are not long-term, viable options for the county. The prohibitive costs of building and rebuilding levees is not a responsible use of tax dollars. Dredging to the extent the county used to do decades ago is not only illegal but expensive.

Pierce County has, instead, purchased properties prone to flooding or have flooded repeatedly from willing sellers. After these properties are purchased, any buildings, driveways and other improvements are removed. The land is returned to a more natural state.

Property Acquisition Program
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Recent Events


The last major Pierce County river flooding in 2009 resulted in a significant impact to people’s lives and threatened infrastructure. Smaller, more localized flooding has occurred as recently as 2015.
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