California Code, Public Utilities Code - PUC § 1757.1

(a) In any proceeding other than a proceeding subject to the standard of review under Section 1757, review by the court shall not extend further than to determine, on the basis of the entire record which shall be certified by the commission, whether any of the following occurred:

(b) In reviewing decisions pertaining solely to water corporations, the review shall not be extended further than to determine whether the commission has regularly pursued its authority, including a determination whether the order or decision under review violates any right of the petitioner under the Constitution of the United States or this state.

(c) No new or additional evidence shall be introduced upon review by the court. The findings and conclusions of the commission on findings of fact shall be final and shall not be subject to review except as provided in this article. The questions of fact shall include ultimate facts and findings and conclusions of the commission on reasonableness and discrimination.