The provisions of *RCW
85.08.280,
85.08.310,
85.08.320,
85.08.420,
85.08.430, and
85.08.480 through
85.08.520, shall be deemed and hereby are made a part of this chapter insofar as they may be applicable hereto, except that the unpaid assessments or installments thereof, which may have been levied for extraordinary maintenance costs as provided in RCW
85.16.170, shall bear interest at a rate determined by the county legislative authority.