Wat. Code, § 1394

(a) The board may reserve jurisdiction, in whole or in part, to amend, revise, supplement, or delete terms and conditions in a permit under either of the following circumstances:

(1) If the board finds that sufficient information is not available to finally determine the terms and conditions which will reasonably protect vested rights without resulting in waste of water or which will best develop, conserve, and utilize in the public interest the water sought to be appropriated, and that a period of actual operation or time for completion of studies will be necessary in order to secure the required information.

(2) If the application or applications being acted upon represent only part of a coordinated project, other applications for the project being pending, and the board finds that the coordinated project requires coordinated terms and conditions which cannot reasonably be decided upon until a decision is reached on the other pending applications.

(b) Jurisdiction shall be reserved under this section for no longer period of time than the board finds to be reasonably necessary, and in no case shall jurisdiction be exercised after the issuance of the license. The jurisdiction shall be exercised only after notice to the parties and a hearing.