Intends to help facilitate a collaborative process to develop a flood mitigation plan for the upper Chehalis subbasin.

Declares that the Chehalis basin partnership is the watershed planning unit under chapter 90.82 RCW for water resource inventory areas twenty-two and twenty-three, as established in chapter 173-500 WAC as it exists on the effective date of this act.

Provides that certain events must occur if, by December 31, 2008, Grays Harbor, Lewis, and Thurston counties create a joint flood control district or exercise equivalent flood control authority under Title 86 RCW covering a substantial portion of the Chehalis basin.

Expires July 1, 2010.