CA Welf & Inst Code Section 246

The presiding judge of the superior court shall annually, in the month of January, designate one or more judges of the court to hear all cases under this chapter during the ensuing year, and shall, from time to time, designate such additional judges as may be necessary for the prompt disposition of the judicial business before the juvenile court.

In all counties where more than one judge is designated as a judge of the juvenile court, the presiding judge of the superior court shall also designate one such judge as presiding judge of the juvenile court.