(1) Forestland on which the right of future development has been acquired by any local government, the state of Washington, or the United States government shall be exempt from special benefit assessments in lieu of assessment for the purposes in the same manner, and under the same liabilities for payment and interest, as land designated under this chapter as forestland, for as long as the designation applies.

(2) Any interest, development right, easement, covenant, or other contractual right that effectively protects, preserves, maintains, improves, restores, prevents the future nonforest use of, or otherwise conserves forestland shall be exempt from special benefit assessments as long as the development right or other interest effectively serves to prevent nonforest development of the land.