Wash. Rev. Code § 35.43.182
If an owner of property enters into an agreement with a city or town waiving the property owner's right under RCW 35.43.180 to protest formation of a local improvement district, the agreement must specify the improvements to be financed by the district and shall set forth the effective term of the agreement, which shall not exceed ten years. The agreement must be recorded with the auditor of the county in which the property is located. It is against public policy and void for an owner, by agreement, as a condition imposed in connection with proposed property development, or otherwise, to waive rights to object to the property owner's individual assessment (including the determination of special benefits allocable to the property), or to appeal to the superior court the decision of the city or town council affirming the final assessment roll.
RCW 35.43.182
Severability-Prospective application-Section captions-1988 c 179: See RCW 39.92.900 and 39.92.901.