Wash. Rev. Code § 36.88.010
All counties have the power to create county road improvement districts for the acquisition of rights-of-way and improvement of county roads, existing private roads that will become county roads as a result of this improvement district process and, with the approval of the state department of transportation, state highways; for the construction or improvement of necessary drainage facilities, bulkheads, retaining walls, and other appurtenances therefor, bridges, culverts, sidewalks, curbs and gutters, escalators, or moving sidewalks; and for the draining or filling of drainage potholes or swamps. Such counties have the power to levy and collect special assessments against the real property specially benefited thereby for the purpose of paying the whole or any part of the cost of such acquisition of rights-of-way, construction, or improvement.
RCW 36.88.010
Reviser's note: This section was amended by 1985 c 369 s 7 and by 1985 c 400 s 3, each without reference to the other. Both amendments are incorporated in the publication of this section pursuant to RCW 1.12.025(2). For rule of construction, see RCW 1.12.025(1).
County may fund improvements to state highways: RCW 36.75.035.