California Code, Government Code - GOV § 38759

If an action or proceeding is brought in any court by the city, or any taxpayer or other person on its behalf, or by any person having an interest in the transaction, for the purpose of setting the transfer aside or avoiding it, any judgment setting aside or avoiding the transfer is void, unless it provides for the restoration to the municipal water district of the consideration paid for the waterworks.  The municipal water district shall not be compelled to surrender possession of the waterworks until the consideration is restored.