When the council, after the aforesaid hearing or hearings, shall determine to proceed with the improvement, it shall pass an ordinance assessing the various lots, parcels and tracts of property specially affected thereby with their apportioned share of the cost of the improvement, together with an amount sufficient to pay a proportionate part of the cost of administering the bond assessment program and issuing the bonds authorized under ORS 223.235, including, but not limited to, legal printing and consultant’s fees. The ordinance shall set forth the time within which such assessment must be paid or bonded and the rate of interest which shall accrue on the unpaid assessments after said date. The assessment ordinance shall further provide the time within which bonded assessments must be paid, not to exceed thirty (30) years. The passage of such assessment ordinance may be delayed until the contract for the work is let, or the improvement completed and the total cost thereof determined. (Prior code § 2.014)