California Code, Government Code - GOV § 53862

(a) The local agency has instituted a proceeding for the construction or maintenance of a public improvement or for the acquisition of necessary land or property.

(b) The cost of the construction, acquisition, or maintenance of such improvement or land or property is required by law to be paid for by an assessment levied upon property benefited by the improvement pursuant to the law under which the improvement is constructed, acquired, or maintained.

(c) The law provides for the sale of the property upon which any such assessment is levied for nonpayment.