Sts. & Hy. Code, § 5502

A reassessment shall be ordered under any one of the following circumstances:

(a) Whenever the owner or holder of any assessments, or bonds issued under this division to represent or be secured by assessments, or the person who would own or hold any such assessment or bonds if they were issued, requests the legislative body to order a reassessment. In such event if the legislative body is of the opinion that the assessments or bonds in question are not enforceable, it shall order the making and issuing of a reassessment covering only the assessments owned or held by the petitioner, or the assessments represented or secured by the bonds owned or held by such petitioner, or which would be owned or held by petitioner if issued.

(b) Whenever any court of competent jurisdiction in any action to foreclose the lien of any assessment or to enforce the obligation of any bond issued to represent or be secured by any assessments issued under this division for any reason holds such lien unenforceable, then it shall in and by its decree direct the making of a reassessment to cover the assessments involved in such action.

(c) Whenever any court of competent jurisdiction in any action to set aside the lien of any assessment or of any bond representing any assessment or in any action to quiet title against the lien of any such assessment, or bond, or in any action to enjoin the making, filing, confirmation or issuance of any assessment or bond to pay for the cost and expenses of any work done under this division, in its judgment decrees such assessments or bonds to be void or unenforceable, or enjoins the making, filing or issuance or confirmation of any such assessment or bond, then it shall in and by its decree direct the making of a reassessment to cover the assessments involved in such action.

(d) Whenever any contractor or assignee of a contractor has done or performed any work pursuant to proceedings had and taken in attempted compliance with this division, and whenever prior to the issuance of any assessment, any court of competent jurisdiction in any action to invalidate the contract or any of such proceedings for any reason declares the contract or other proceedings to be invalid, then such court shall in and by its decree direct the making of a reassessment for the reasonable value of the work actually done and performed in good faith by the contractor, or such portion thereof as was of a kind that could lawfully have been ordered under the provisions of this division.