When the court has made its final decree, confirming said report or fixing the assessments in each case, the assessments of benefits shall become and be liens upon the property assessed, and collected as now provided by law. Said assessment of benefits shall bear interest at the expiration of thirty days from the confirmation of the report or the making of the decree, and may be collected by action of assumpsit; the lien of the judgment, however, to be limited to the property assessed.
53 P.S. § 2814