Cal. Gov. Code § 895.2
Whenever any public entities enter into an agreement, they are jointly and severally liable upon any liability which is imposed by any law other than this chapter upon any one of the entities or upon any entity created by the agreement for injury caused by a negligent or wrongful act or omission occurring in the performance of such agreement.
Notwithstanding any other law, if a judgment is recovered against a public entity for injury caused in the performance of an agreement, the time within which a claim for such injury may be presented or an action commenced against any other public entity that is subject to the liability determined by the judgment under the provisions of this section begins to run when the judgment is rendered.
Ca. Gov. Code § 895.2