Wash. Rev. Code § 87.03.505
Whenever, by reason of the sale of land within a local improvement district for unpaid taxes or assessments, or for any other reason, it may appear apparent that the remaining lands within any such local improvement district are and will be unable to pay out the cost of such improvement or the bond issue or contract indebtedness therefor, the landowners of the local improvement district may petition the directors of the irrigation district or the directors of the district may upon their own initiative, and either upon receipt of such petition or the passing of such resolution the directors of the irrigation district shall cause a complete survey to be made of the affairs of the local improvement district pertaining to the payment of the cost of said improvement, and shall determine the amount of property remaining in the hands of private owners that is still subject to assessment for the improvement, the amount of land standing in the name of the district which is subject to assessment for said improvement and the amount of any lands which may have been entirely removed from the liability of any such assessments, and such other and pertinent data as may be necessary, in order to determine the ability of said remaining private property to pay the remaining balance of the cost of said improvement, and if as a result thereof it shall appear that the remaining private property will be unable to pay the said remaining cost of the improvement, the said board of directors shall determine what amount and to what extent the remaining private property will be able to equitably pay on the cost of said improvement which shall include the privately owned property and district owned property and such remaining portion of the cost of said improvement which the directors find said land can equitably pay and in such amounts as in the judgment of the directors shall appear equitable after taking all circumstances into consideration, shall be assessed against the lands within such local improvement district and shall be levied and collected in the manner as in this act provided for the assessment and collection of construction costs and shall be payable over a period of not more than twenty years. Notwithstanding all provisions in this chapter contained for the assessment, equalization, levy and collection of assessments no election shall be required to authorize the issue of bonds or the entering into a contract to cover the cost thereof. Assessments when collected by the county treasurer for the payment shall constitute a special fund to be called "bond redemption or contract repayment fund of local improvement district No. . . . . . ."
The costs or any unpaid portion thereof, of any such assessment, charged or to be charged or assessed against any tract of land may be paid in one payment by the owner or by any one acting for such owner, under and pursuant to such rules as the board of directors may adopt, and all such amounts shall be paid to the county treasurer who shall place the same in the appropriate fund. Upon the payment in full of the amount charged or to be charged or assessed against any particular tract of land, said tract of land shall be thereupon entirely, fully and finally released of any and all further liability by reason of such improvement and the amount charged or to be charged and assessed against each tract of land as designated by said board shall be the limit of the liability of said tract of land for the costs of said improvement, except insofar as said land may be additionally liable by reason of being within the irrigation district and being liable for its portion of the general obligation of the district. The determination of the amount charged or to be charged or assessed against any tract of land may be appealed by the owner of said tract from the decision of the board of directors to the superior court of the county in which the property is located at any time within twenty days from the date of the passage of a resolution by the board of directors with reference thereto: PROVIDED, HOWEVER, That in the event said irrigation district shall have borrowed or have an application on file for the borrowing of money from the reconstruction finance corporation, or its successor, or has entered into a contract with the United States or the state of Washington, or both, then in that event before any such reassessment shall be made it shall first receive the approval of said reconstruction finance corporation, or its successor or the United States or the state of Washington, or both, as the case may be.
RCW 87.03.505
Assessment, equalization, levy and collection of assessments for irrigation district purposes: RCW 87.03.240 through 87.03.280.