California Code, Public Resources Code - PRC § 5548

The president shall preside over all meetings of the board. He shall sign all contracts and conveyances on behalf of the district after they have been approved by the board, and he shall perform such other duties as may be imposed upon him by the board.

In the absence of the president, or in the event of his inability to act, the vice president shall perform all the powers and duties of the president.

If both the president and vice president are absent or unable to act, the board may select a president pro tempore, who shall perform all the powers and duties of the president.