Wash. Rev. Code § 8.24.010
An owner, or one entitled to the beneficial use, of land which is so situate with respect to the land of another that it is necessary for its proper use and enjoyment to have and maintain a private way of necessity or to construct and maintain any drain, flume or ditch, on, across, over or through the land of such other, for agricultural, domestic or sanitary purposes, may condemn and take lands of such other sufficient in area for the construction and maintenance of such private way of necessity, or for the construction and maintenance of such drain, flume or ditch, as the case may be. The term "private way of necessity," as used in this chapter, shall mean and include a right-of-way on, across, over or through the land of another for means of ingress and egress, and the construction and maintenance thereon of roads, logging roads, flumes, canals, ditches, tunnels, tramways and other structures upon, over and through which timber, stone, minerals or other valuable materials and products may be transported and carried.
RCW 8.24.010