Cal. Wat. Code § 125
For the purpose of administration, the director shall organize the department with the approval of the Governor in the manner he deems necessary to segregate and conduct the work of the department properly. With the approval of the Governor, the director may create such divisions and subdivisions as may be necessary and change or abolish them from time to time.
The director with the approval of the Governor may establish branch offices in hydrographic or other regions of the State in order to assure the expeditious conduct of the work of the department in such region, and to assure free and rapid communication of local problems and recommendations to the department and may change or abolish any such branch offices from time to time. Any branch office so established shall be under the control of a branch office manager who, subject to the direction and control of the director, shall represent the department in all matters under the department's jurisdiction in the region.
Ca. Water Code § 125