California Code, Water Code - WAT § 2816

All persons claiming rights under incomplete appropriations who fail to complete their appropriations within the limit of time fixed by the board in its order of determination, or within such further time granted upon motion made prior to the expiration of the time limit as the court finds equitable and just, shall be deemed to have abandoned their rights of appropriation insofar as the same remain incomplete, and such appropriators shall be deemed and held to have no right, title or interest in or to the water of the stream system insofar as their appropriations have not been completed.