That each improvement assessment, with any penalty or interest incident to the nonpayment thereof, shall constitute a lien upon the lot or parcel of benefited property against which it is assessed. The lien shall attach to each lot or parcel of benefited property at the time the annual improvement assessment is made, and thereupon shall take precedence over all othe liens, whether created prior to or subsequent to the making of such improvement assessment, except State, county and municipal property taxes, and prior special assessments. Said lien shall not be defeated or postponed by any private or judicial sale, by any mortgage, or by any error or mistake in the description of the property or in the names of the owners, if the description is sufficient to identify the property subject to the assessment. No irregularity in the proceedings of the governing body shall exempt any benefited property from the lien for the improvement assessment, or from the payment thereof or from the penalties or interest thereon. [As added by Priv. Acts 1970, ch. 276, § 13]