The legislature recognizes the need to mitigate the effects of sedimentary build-up and resultant damage to fish population in the Toutle river resulting from the Mt. St. Helens eruption. The state has entered into a contractual agreement with the United States army corps of engineers designed to minimize fish habitat disruption created by the sediment retention structure on the Toutle river, under which the corps has agreed to construct a fish collection facility at the sediment retention structure site conditional upon the state assuming the maintenance and operation costs of the facility. The department shall operate and maintain a fish collection facility on the Toutle river.