Any city or town shall have power to provide for the protection of such city or town, or any part thereof, from overflow, and to establish, construct and maintain dikes, levees, embankments, or other structures and works, or to open, deepen, straighten or otherwise enlarge natural watercourses, waterways and other channels, including the acquisition or damaging of lands, rights-of-way, rights and property therefor, within or without the corporate limits of such city or town, and to manage, regulate and control the same.
RCW 35.21.090
Eminent domain: Chapter 8.12 RCW.