Health and Safety Code § 33502

The judgment shall determine the validity or invalidity, respectively, of the matters specified in Section 33501. The judgment shall be subject to being reopened under Section 473 or Section 473.5 of the Code of Civil Procedure or otherwise only within 90 days after the entry of the judgment and petitioner and any person who has appeared in the special proceeding shall have the right to move for a new trial under proper circumstances and upon appropriate grounds and to appeal from the judgment.