Wash. Rev. Code § 85.05.076
Any person deeming himself or herself aggrieved by the assessment for benefits made against any lot or parcel of land owned by him or her, may appeal therefrom to the superior court for the county in which the diking district is situated; such appeal shall be taken within the time and substantially in the manner prescribed by the laws of this state for appeals from justices' courts and all notices of appeal shall be filed with the said board, and the board of diking commissioners shall at the appellant's expense certify to the superior court so much of the record as appellant may request, and the hearing in said superior court shall be de novo, and the superior court shall have power and authority to reverse or modify the determination of the commissioners and to certify the result of its determination to the county auditor and shall have full power and authority to do anything in the premises necessary to adjust the assessment upon the lots or parcels of land involved in the appeal in accordance with the benefits.
RCW 85.05.076