Cal. Wat. Code § 10500
The department shall make and file applications for any water which in its judgment is or may be required in the development and completion of the whole or any part of a general or coordinated plan looking toward the development, utilization, or conservation of the water resources of the state.
Any application filed pursuant to this part shall be made and filed pursuant to Part 2 (commencing with Section 1200) of Division 2 of this code and the rules and regulations of the State Water Resources Control Board relating to the appropriation of water insofar as applicable thereto.
Applications filed pursuant to this part shall have priority, as of the date of filing, over any application made and filed subsequent thereto. The statutory requirements of Part 2 (commencing at Section 1200) of Division 2 relating to diligence shall not apply to applications filed under this part, except as otherwise provided in Section 10504.
Ca. Water Code § 10500