Wash. Rev. Code § 85.07.140
If the court is satisfied that the status of said property has changed so that it is no longer susceptible to benefit from the improvement of such district and should be removed from the assessment roll thereof, and it be established that all benefits assessed against said lands up to the date of trial have been paid, such court may enter a decree striking such land from the assessment roll of said district, and it shall not be subject to future assessment for benefits or maintenance by such district, unless, thereafter, it is again brought into such districts by the proceedings provided by law to extend the district or include benefited property which is not assessed. Nothing herein shall prevent such property from being again brought into said district in the manner provided by law generally for the inclusion of benefited property, if it appear at a future date that said property will receive benefits from the improvement in such district. Upon entry of such decree of the court a certified copy thereof shall be filed in the office of the auditor of such county wherein the property is situated, and upon receipt thereof, he or she shall correct the assessment roll of said district accordingly and strike the property therefrom.
RCW 85.07.140