Wash. Rev. Code § 86.26.090
The state shall participate with eligible local authorities in maintaining and restoring the normal and reasonably stable river and stream channel alignment and the normal and reasonably stable river and stream channel capacity for carrying off flood waters with a minimum of damage from bank erosion or overflow of adjacent lands and property; and in restoring, maintaining and repairing natural conditions, works and structures for the maintenance of such conditions. State participation in the repair of flood control facilities may include the enhancement of such facilities. The state shall likewise participate in the restoration and maintenance of natural conditions, works or structures for the protection of lands and other property from inundation or other damage by the sea or other bodies of water. Funds from the flood control assistance account shall not be available for maintenance of works or structures maintained solely for the detention or storage of flood waters.
RCW 86.26.090
Findings-Intent-Purpose-1991 c 322: See notes following RCW 86.12.200.