At the final hearing no evidence shall be heard against the genuineness or sufficiency of the petition or notice unless it is shown to the satisfaction of the board of supervisors that new evidence which if uncontradicted would disprove the genuineness or sufficiency of the petition or notice has been discovered since the board adopted the preliminary formation resolution. In case any new evidence is admitted, full opportunity shall be given for the introduction of evidence in rebuttal.
Ca. Water Code § 20846