Cal. Water Code § 1014

The transfer of water, or the offer of water for transfer, shall not cause, or be the basis for, a forfeiture, abandonment, or modification of any water right, contract right, or other right to the use of that water. An offer of water for transfer, contract negotiations, or a transfer agreement shall not be used as evidence of waste or unreasonable use, or of cessation of use, of the water made available for transfer.