Cal. Wat. Code § 1219
A water supplier exporting or intending to export water outside a protected area, or a water user or users within a protected area, may declare that an impasse has been reached between the parties in negotiations over matters within the scope of negotiations specified in Section 1217 and may request the director to appoint a panel of five disinterested persons from whom the parties shall select, by a process of elimination, the mediator. After drawing lots to determine the order, the parties shall each, in turn, eliminate a name from the panel until there is only one person remaining on the panel, who shall be the mediator. The mediator shall meet forthwith with the parties or their representatives, either jointly or separately, and shall take such other steps as the mediator may deem appropriate in order to persuade the parties to resolve their differences and effect a mutually acceptable agreement. The services of the mediator, including any per diem fees, and actual and necessary travel and subsistence expenses, shall be provided by the parties. Nothing in this section shall be construed to prevent the parties from mutually agreeing upon their own mediation procedure, and in the event of such agreement, the director shall not appoint a mediator.
Ca. Water Code § 1219