Special assessments and all interest and charges thereon, from the date of confirmation of the roll, shall be and remain a lien upon the property assessed of the same character and effect as the lien created by general law for the State and County taxes and by this Charter for City taxes, until paid. From such date after confirmation as shall be fixed by the Council, the same collection fees, penalties and interest shall be paid on delinquent special assessments and upon delinquent installments of such special assessments as are provided by this Charter to be paid on delinquent City taxes. In case any assessment or any part thereof shall remain unpaid on the first Monday of May following the date when the same became delinquent, the same shall be reported unpaid by the Treasurer to the Council, and such delinquent assessments, together with all accrued interest, shall be transferred and reassessed on the next annual City tax roll in a column headed "special assessments" with a penalty of four percent upon such total amount added thereto, and when so transferred and reassessed upon said tax roll shall be collected in all respects as provided for the collection of City taxes.